SRF2013 - List of Keywords (linac)

Paper	Title	Other Keywords	Page
MOIOA01	The FRIB Project at MSU	cavity, cryomodule, ion, operation	1
	M. Leitner, B. Bird, F. Casagrande, S. Chouhan, C. Compton, J.L. Crisp, K. Elliott, A. Facco, A.D. Fox, M. Hodek, M.J. Johnson, G. Kiupel, I.M. Malloch, D. Miller, S.J. Miller, D. Morris, D. Norton, R. Oweiss, J.P. Ozelis, J. Popielarski, L. Popielarski, A.P. Rauch, R.J. Rose, K. Saito, M. Shuptar, N.R. Usher, G.J. Velianoff, D.R. Victory, J. Wei, J. Whitaker, K. Witgen, T. Xu, Y. Xu, O. Yair, S. Zhao FRIB, East Lansing, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. The Facility for Rare Isotope Beams (FRIB) is ready to start construction. The facility will utilize a high-intensity, heavy-ion driver linac to provide stable ion beams from protons to uranium up to energies of >200 MeV/u and at a beam power of up to 400 kW. The superconducting cw linac consists of 330 individual low-beta (β = 0.041, 0.085, 0.29, and 0.53 at 80.5 MHz and 322 MHz) cavities in 49 cryomodules operating at 2 K. This paper discusses the current development status of the project with emphasis on the linac SRF acquisition. SRF coldmass and cryomodule component designs are briefly summarized. A SRF production facility, currently under construction, is described.
	Slides MOIOA01 [9.804 MB]

MOIOA02	Status and Challenges of Spiral2 SRF Linac	cryomodule, cavity, vacuum, ion	11
	R. Ferdinand, P.-E. Bernaudin, M. Di Giacomo GANIL, Caen, France P. Bosland CEA/IRFU, Gif-sur-Yvette, France Y. Gómez Martínez LPSC, Grenoble Cedex, France G. Olry IPN, Orsay, France
	GANIL is presently extending its experimental facility with the new SPIRAL2 project. It is based on a multi-beam Superconducting Linac Driver delivering 5 mA deuterons up to 40 MeV and 1 mA heavy ions up to 14.5 MeV/u. Several domains of research in nuclear physics at the limits of stability will be covered by this new accelerator. SPIRAL2 construction has two phases. SPIRAL2 phase 1 includes the superconducting accelerator driver, and the construction of the two research areas where the accelerated protons and deuterons will generate extremely intense neutron beams for fundamental physics experiments and numerous applications. SPIRAL2 will also accelerate stable heavy ion beams of very high intensity. The phase2 includes the RIB production building and links to the existing GANIL accelerator complex for RIB post acceleration. The Superconducting Linac incorporates many innovative developments of the Quarter-Wave resonators and their associated cryogenic and RF systems. The installation of the SPIRAL2 accelerator at GANIL has started. Status of the Spiral 2 SRF linac will be presented, focusing on the various SRF challenges met by this project and how/what solutions were chosen. * on behalf of the SPIRAL2 project and superconducting teams
	Slides MOIOA02 [87.841 MB]

MOIOA04	SRF Challenges for Energy Recovery Linacs	cavity, SRF, HOM, operation	24
	A. Burrill HZB, Berlin, Germany
	Many of the challenges associated with operating a SRF ERL are independent of the choice of operating frequency, beam energy, and overall purpose of the machine. Worldwide there are an increasing number of ERLs in various stages of development and operation which are facing a number of similar challenges and often solving them in very different ways. In this talk I will seek to summarize the main challenges the community as a whole faces, address how different laboratories are working to solve these problems, and seek to identify areas of overlap where the community can work together to solve some of these common problems.
	Slides MOIOA04 [5.213 MB]

MOIOA05	SRF in Heavy Ions Projects	cavity, ion, heavy-ion, cryomodule	30
	D. Jeon IBS, Daejeon, Republic of Korea
	SRF technologies are widely applied to heavy ion accelerator projects in the world such as the RAON, C-ADS, HIAF, FRIB, SPIRAL2, ISAC-II, HIE-ISOLDE etc. In this talk, status report, design choices and SRF challenges met in heavy ion machines are presented.
	Slides MOIOA05 [10.228 MB]

MOIOB01	High Power Proton/Deuteron Accelerators	SRF, proton, operation, cavity	35
	J.-L. Biarrotte IPN, Orsay, France
	High power proton and deuteron linear accelerators can give rise to a large variety of scientific applications, useful for both fundamental and applied research. Thanks to the on-going efficient development of the superconducting RF technology, more and more projects based on such machines have emerged during the last 2 decades. This paper will review these existing high power proton/deuteron accelerator facilities or projects, trying in particular to emphasize in each case the various specificities and challenges related to the SRF technology.
	Slides MOIOB01 [4.474 MB]

MOP002	Conceptual Design for Replacement of the DTL and CCL with Superconducting RF Cavities in the Spallation Neutron Source Linac	cryomodule, DTL, cavity, klystron	69
	M.S. Champion, M. Doleans, S.-H. Kim ORNL, Oak Ridge, Tennessee, USA
	Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. The Spallation Neutron Source Linac utilizes normal conducting RF cavities in the low energy section from 2.5 MeV to 186 MeV. Six Drift Tube Linac (DTL) structures accelerate the beam to 87 MeV, and four Coupled Cavity Linac (CCL) structures provide further acceleration to 186 MeV. The remainder of the Linac is comprised of 81 superconducting cavities packaged in 23 cryomodules to provide a final beam energy of approximately 1 GeV. The superconducting Linac has proven to be substantially more reliable than the normal conducting Linac despite the greater number of stations and the complexity associated with the cryogenic plant and distribution. A conceptual design has been initiated on a replacement of the DTL and CCL with superconducting RF cavities. The motivation, constraints, and conceptual design are presented.

MOP003	Implications of Increased Beam Current for the Diamond Storage Ring RF System	cavity, storage-ring, operation, cathode	73
	C. Christou, A. Bogusz, P. Gu, M. Maddock, P.J. Marten, S.A. Pande, A.F. Rankin, D. Spink, A.V. Watkins Diamond, Oxfordshire, United Kingdom
	Diamond Light Source presently operates for users with 300mA beam current and initial tests have begun to upgrade this current towards an ultimate goal of 500mA. The implications of such a beam current increase for the storage ring RF system will be significant, including the installation of a third superconducting cavity and a possible modification of the coupling parameters of the existing cavities. An overview of the planned enhancements of the RF system is presented, including an update of the procurement of a new CESR-design cavity and options for installation and operation of this cavity and supporting infrastructure.

MOP004	The ESS Superconducting Linear Accelerator	cryomodule, cavity, SRF, lattice	77
	C. Darve, M. Eshraqi, M. Lindroos, D.P. McGinnis, S. Molloy ESS, Lund, Sweden P. Bosland CEA/IRFU, Gif-sur-Yvette, France S. Bousson IPN, Orsay, France
	The European Spallation Source (ESS) is one of Europe's largest planned research infrastructure. The collaborative project is funded by a collaboration of 17 European countries and is under design and construction in Lund, Sweden. The ESS will bring new insights to the grand challenges of science and innovation in fields as diverse as material and life sciences, energy, environmental technology, cultural heritage solid-state and fundamental physics. A 5 MW, long pulse proton accelerator is used to reach this goal. The pulsed length is 2.86 ms, the repetition frequency is 14 Hz (4 % duty cycle). The choice of SRF technology is a key element in the development of the ESS linear accelerator(linac). The superconducting linac is composed of one section of spoke cavity cryomodule (352 MHz) and two sections of elliptical cavity cryomodules (704 MHz). These cryomodules contain Niobium SRF cavities operating at 2 K. This paper presents the superconducting linac layout and its lifecycle.

MOP006	Status of the SC CW-Linac Demonstrator	cavity, solenoid, status, emittance	80
	V. Gettmann, W.A. Barth, S. Jacke, S. Mickat, S. Mickat, A. Orzhekhovskaya GSI, Darmstadt, Germany M. Amberg, K. Aulenbacher, W.A. Barth, S. Jacke, S. Mickat HIM, Mainz, Germany M. Amberg, F.D. Dziuba, H. Podlech, U. Ratzinger IAP, Frankfurt am Main, Germany K. Aulenbacher IKP, Mainz, Germany
	The commissioning of the superconducting (sc) continuous wave (cw) LINAC Demonstrator, financed by the Helmholtz Institute Mainz (HIM) mainly, is planned in 2014. The aim is a “full performance test” at GSI-High Charge Injector (HLI) of a 217 MHz sc CH-Cavity, which is designed by the Institute of Applied Physics (IAP) of the University Frankfurt. Inside the cryostat a suspended frame supports the cavity embedded by two solenoids. All of these components are in fabrication. The testing environment is about to be completed. The radiation protection bunker, and the beam transport line straightforward to the GSI-HLI, comprising beam diagnostic components as well as focusing and steering magnets, has been mounted.

MOP007	The Status of Superconducting Linac and SRF Activities at the SNS	cryomodule, cavity, operation, SRF	83
	S.-H. Kim, W. Blokland, M.S. Champion, A. Coleman, M.T. Crofford, M. Doleans, D.L. Douglas, T.V. Gorlov, M.P. Howell, Y.W. Kang, A.P. Shishlo, S.E. Stewart, W.H. Strong ORNL, Oak Ridge, Tennessee, USA R. Afanador, B. DeGraff, B.S. Hannah, S.W. Lee, C.J. McMahan, T.S. Neustadt, S.W. Ottaway, C.C. Peters, J. Saunders, D.M. Vandygriff ORNL RAD, Oak Ridge, Tennessee, USA
	Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE. There have been substantial gains at the Spallation Neutron Source (SNS) in last 7 years in understanding pulsed superconducting linac (SCL) operation including system and equipment limiting factors and resolution of system and equipment issues. Significant effort and focus are required to assure ongoing success of the operation, maintenance and improvement of the SCL, and to address the requirements of the upgrade project in the future. The SNS is taking a multi-faceted approach to maintaining and improving its linac. A balanced set of facilities which support processing, assembly, repair, and testing of cavities/cryomodules are currently being placed into service. This paper summarizes the status of the SNS SCL and related superconducting radio-frequency (SRF) activities such as development of ASME code-stamped spare cryomodules, R&D activities for SRF cavity performance improvements, SRF cavity development for power upgrade project and SRF facility development/upgrade to support all required activities.

MOP008	SUPERCONDUCTING LINAC FOR THE RISP	cavity, cryomodule, proton, ion	89
	H.J. Kim, H.J. Cha, M.O. Hyun, H.J. Jang, D. Jeon, J.D. Joo, M.J. Joung, H.C. Jung, Y. Jung, Y. Kim, M. Lee, G.-T. Park IBS, Daejeon, Republic of Korea
	The RISP (Rare Isotope Science Project) accelerator has been planned to study heavy ion of nuclear, material and medical science at the Institute for Basic Science (IBS). It can deliver ions from proton to Uranium. The facility consists of three superconducting linacs of which superconducting cavities are independently phased. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the RISP linac design, the superconducting cavity, and cryomodule.

MOP010	Spiral2 Cryomodules B Tests Results	cryomodule, cavity, operation, alignment	95
	G. Olry, F. Chatelet, C. Commeaux, N. Gandolfo, D. Grolet, C. Joly, J. Lesrel, D. Longuevergne, R. Martret, G. Michel, L. Renard, A. Stephen, P. Szott IPN, Orsay, France P.-E. Bernaudin, R. Beunard, R. Ferdinand, A. Lefevre GANIL, Caen, France Y. Gómez Martínez LPSC, Grenoble Cedex, France
	Assembly and tests of the SPIRAL2 superconducting linac's cryomodules at CEA/Saclay and IPN/Orsay have now reached cruising speed after having faced a series of problems, among them contamination. 19 cryomodules are composing the whole Linac and IPN Orsay is in charge of the 7 cryomodules B, housing two 88MHz, beta 0.12 Quarter-Wave Resonators. Two cryomodules have been successfully assembled and tested up to the nominal gradient of 6.5 MV/m for all cavities with also total cryogenic losses under specifications. One of them is fully qualified and has been already delivered to GANIL. The second one showed misalignment on one cavity which could lead to partial disassembly. This paper will present the results of those cryomodules tests as well as the status of the remaining ones.

MOP011	European XFEL 3.9 GHz System	cavity, HOM, cryomodule, controls	100
	P. Pierini, M. Bertucci, A. Bosotti, C. Maiano, P. Michelato, L. Monaco, R. Paparella, D. Sertore INFN/LASA, Segrate (MI), Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy E. Vogel DESY, Hamburg, Germany
	The third harmonic system of the European XFEL is a joint INFN and DESY contribution to the project. Achievements, status and activity plan will be reviewed.

MOP012	Completion of the Superconducting Heavy Ion Linac at Inter-University Accelerator Centre	operation, electronics, ion, controls	103
	A. Rai, R. Ahuja, J. Antony, S. Babu, J. Chacko, G.K. Chaudhari, A. Chaudhary, T.S. Datta, R.N. Dutt, S. Ghosh, R. Joshi, D. Kanjilal, S. Kar, J. Karmakar, M. Kumar, R. Kumar, D.S. Mathuria, R. Mehta, K.K. Mistri, A. Pandey, P. Patra, P.N. Prakash, A. Roy, J. Sacharias, B.K. Sahu, A. Sarkar, S.S.K. Sonti, S. K. Suman, J. Zacharias IUAC, New Delhi, India
	The Superconducting heavy ion Linac at Inter University Accelerator Centre (IUAC), New Delhi has been delivering accelerated ion beams to the users since 2009 . Initially the first accelerating module, housing eight Quarter Wave Resonators (QWR’s), became operational together with the Superbuncher having one and the Rebuncher having two QWR’s, respectively. In the subsequent years, the remaining two modules have been installed and commissioned. The complete Linac was operated recently and several ion beams were delivered for scheduled experiments. The maximum energy gain was 8 MeV per charge state. Operational highlights include successful operation of four resonators in the third module with Piezo based * mechanical tuning, implementation of remote phase locking for all resonators in three modules, development of a scheme for auto locking of resonators and testing of a capacitive pickup as a beam diagnostic element. Details will be presented vis-à-vis the problems encountered and the future course of action. * A. Rai et. al., Proc. of SRF2009 Sept. 20–25, 2009, Berlin, Germany, page 244. ** B.K.Sahu et. al., Proc. of IPAC 2010, Kyoto Japan, page 2920.

MOP015	Status of the SRF Development for the Project X	cavity, cryomodule, SRF, proton	117
	V.P. Yakovlev, T.T. Arkan, M.H. Awida, P. Berrutti, E. Borissov, A.C. Crawford, M.H. Foley, C.M. Ginsburg, I.V. Gonin, A. Grassellino, C.J. Grimm, S.D. Holmes, S. Kazakov, R.D. Kephart, T.N. Khabiboulline, V.A. Lebedev, A. Lunin, M. Merio, S. Nagaitsev, T.H. Nicol, Y.O. Orlov, D. Passarelli, T.J. Peterson, Y.M. Pischalnikov, O.V. Pronitchev, L. Ristori, A.M. Rowe, D.A. Sergatskov, N. Solyak, A.I. Sukhanov, I. Terechkine Fermilab, Batavia, USA
	Project X is a high intensity proton facility being developed to support a world-leading program of Intensity Frontier physics over the next two decades at Fermilab. The proposed facility is based on the SRF technology and consists of two linacs: CW linac to accelerate beam from 2.1 MeV to 3 GeV and pulsed linac accelerate 5% of the beam up to 8 GeV. In a CW linac five families of SC cavities are used: half-wave resonators (162.5 MHz); single-spoke cavities: SSR1 and SSR2 (325 MHz) and elliptical 5-cell β=0.6 and β=0.9 cavities (650 MHz). Pulsed 3-8 GeV linac linac are based on 9-cell 1.3 GHz cavities. In the paper the basic requirements and the status of development of SC accelerating cavities, auxiliaries (couplers, tuners, etc.) and cryomodules are presented as well as technology challenges caused by their specifics.

MOP017	SRF for Low Energy RHIC Electron Cooling: Preliminary Considerations	SRF, gun, electron, cavity	126
	S.A. Belomestnykh, I. Ben-Zvi, M. Blaskiewicz, A.V. Fedotov, D. Kayran, V. Litvinenko, Q. Wu, B. P. Xiao, W. Xu, A. Zaltsman BNL, Upton, Long Island, New York, USA S.A. Belomestnykh, I. Ben-Zvi, V. Litvinenko Stony Brook University, Stony Brook, USA Z.A. Conway, M.P. Kelly, S.V. Kutsaev, B. Mustapha, P.N. Ostroumov ANL, Argonne, USA
	Funding: Work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE A search for the QCD Critical Point has renewed interest to electron cooling ion beams in RHIC at energies below 10 GeV/nucleon. The electron cooling will utilize bunched electron beams form an SRF linac at energies from 0.9 to 5 MeV. The SRF linac will consist of two quarter wave structures: a photoemission electron gun and a booster cavity. In this paper we present preliminary design consideration of this SRF linac.

MOP018	Design of the MYRRHA 17-600 MeV Superconducting Linac	cavity, lattice, operation, simulation	129
	J.-L. Biarrotte IPN, Orsay, France F. Bouly CERN, Geneva, Switzerland J.-P. Carneiro Fermilab, Batavia, USA D. Uriot CEA/DSM/IRFU, France D. Vandeplassche SCK•CEN, Mol, Belgium
	Funding: This work is being supported by the European Atomic Energy Community’s (EURATOM) Seventh Framework Programme under grant agreement n°269565 (MAX project). The goal of the MYRRHA project is to demonstrate the technical feasibility of transmutation in a 100MWth Accelerator Driven System (ADS) by building a new flexible irradiation complex in Mol (Belgium). The MYRRHA facility requires a 600 MeV accelerator delivering a maximum proton flux of 4 mA in continuous operation, with an additional requirement for exceptional reliability. This paper will briefly describe the beam dynamics design of the main superconducting linac section which covers the 17 to 600 MeV energy range and requires enhanced fault-tolerance capabilities.

MOP021	Conceptual Design of SC Linac for RIBF-Upgrade Plan	cryomodule, cavity, quadrupole, ion	137
	K. Yamada, O. Kamigaito, N. Sakamoto, K. Suda RIKEN Nishina Center, Wako, Japan
	For the intensity upgrade of very-heavy ions such as 238U and 124Xe at the RIKEN RI-Beam Factory (RIBF), a design study of new SC linac injector has started on. In the RIBF, the very-heavy ions are accelerated in a cascade of the injector linac (RILAC2), the RIKEN ring cyclotron (RRC), the fixed-frequency ring cyclotron (fRC), the intermediate-stage ring cyclotron (IRC), and the world's first superconducting ring cyclotron (SRC). We plan to substitute the SC linac for the RRC with respect to the very heavy ions, and to boost up the energy of ions with mass-to-charge ratio of 7 from 1.4 MeV/u to 11 MeV/u in the cw mode. The SC cavity is assumed to be a two gap QWR with an rf frequency of 73 MHz, that is twice the rf frequency of IRC and SRC. The cell parameters and number of cavity are determined by calculating the energy gain of synchronous ion by taking the rf phase at the center of gap into account. The transverse motion is calculated by the transfer matrix method and several types of lattice are studied. This contribution reports the progress of design study for the SC linac.

MOP029	Cryo-Losses Measurements of the XFEL Prototype and Pre-Series Cryomodules	cryomodule, operation, cryogenics, electron	162
	S. Barbanotti, J. Eschke, K. Jensch, W. Maschmann, O. Sawlanski DESY, Hamburg, Germany W. Gaj, L.M. Kolwicz-Chodak, W. Maciocha IFJ-PAN, Kraków, Poland X. Wang ESS, Lund, Sweden
	Cryo-losses measurements of the XFEL prototype and pre-series cryomodules are here presented and compared with the XFEL requirements. Cryo-losses at the 4.5 K, 80 K and 2K temperatures are calculated during the test period at CMTB (CryoModule Test Bench) at DESY to qualify the cryomodules before installation. This paper summarizes the test procedure for the different circuits (2K, 4.5K, 80K) and in different load conditions: static losses, losses due to the magnet and dynamic losses due to the RF power sent to the cavities at different MV/m levels.

MOP033	Quality Assurance and Acceptance Testing of Niobium Material for Use in the Construction of the Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU)	niobium, cavity, SRF, controls	174
	C. Compton, D. Miller FRIB, East Lansing, USA T.R. Bieler, D. Kang Michigan State University, East Lansing, USA S.K. Chandrasekaran, N.T. Wright MSU, East Lansing, USA
	Funding: Work supported by US DOE Cooperative Agreement DE-SC0000661 and Michigan State University Niobium is the current material of choice for the fabrication of superconducting radio frequency (SRF) cavities used in SRF based accelerators. Although niobium specifications for this application have been well established, material properties of as-received materials can still vary substantially. As required for the FRIB accelerator, large volumes (60,000 lbs) of niobium materials (sheet, tube, and flange) have been contracted to several niobium vendors. The FRIB cavity designs require very large niobium sheets, increasing the difficulty in fabrication and potential for contamination. FRIB has developed and initiated plans to control niobium specifications and perform incoming acceptance checks to ensure quality is maintained. Acceptance results from the first niobium shipment will be presented, looking at several production lots from the same vendor and across multiple vendors. Non-conforming results were observed and will be discussed including follow-up investigations and mitigation strategies to improve quality of future shipments.

MOP039	Strategy of Technology Transfer of EXFEL Preparation Technology to Industry	cavity, controls, status, hardware	197
	A. Matheisen, J. Iversen, A. Schmidt, W. Singer DESY, Hamburg, Germany P. Michelato, L. Monaco INFN/LASA, Segrate (MI), Italy
	For the EXFEL a specification for the cavitiy preparation procedures (R1)was set up and handed to the industrial companies. Basing on this specification companies hard ware as well as process flows were set up. Beside this specified part of the preparation technique the companies personal needed to be educated and the processes ramped up. To check the quality of the infrastructure, status of education of personal and correct set up of process flows, so called Dummy (DCV) - , Reference (RCV ) and Pre-series (PCV) cavities were assigned. We report on the general strategy applied for the EXFEL technology transfer on cavity preparation and the results obtained on the qualification cavities. R1) Series Surface and acceptance test preparation of superconducting cavities for the European Xfel (XFEL/A - D) JUNE 30, 2009

MOP048	PED Requirements Applied to the Cavity and Helium Tank Manufacturing	cavity, niobium, controls, operation	227
	A. Schmidt, J. Iversen, A. Matheisen, W. Singer DESY, Hamburg, Germany
	For the European XFEL more than 800 Cavities are manufactured by industrial partners. Each cavity is housed in an individual cryo vessel, the so called helium tank. All vessels are made from titanium and manufactured by industry as well. The cavity, welded into its helium tank, is a pressure loaded part and has to follow the pressure equipment directive - PED (97/23/EC). Setting up a series production of cavities and helium tanks by different vendors according given standards, was the task of the EXFEL WPG-1 LINAC-WP04. In cooperation with the TUEV-Nord as the notified body, DESY is responsible for the qualification of design, material in use and reasonable tests to get a certificate for pressure bearing parts.

MOP055	Status of the Superconducting Cavity Development for ILC	cavity, cryomodule, status, HOM	247
	T. Yanagisawa, H. Hara, F. Inoue, K. Kanaoka, K. Sennyu MHI, Hiroshima, Japan
	MHI activities for ILC are reported. MHI had developed several procedure and method of cavity production for stable quality and cost reduction. And we are producing cryomodules too. These activities are reported in detail.

MOP057	Developments and Tests of a 700 MHz Cryomodule for the Superconducting Linac of MYRRHA	cavity, cryomodule, vacuum, cryogenics	250
	F. Bouly CERN, Geneva, Switzerland S. Berthelot, J.-L. Biarrotte, M. El Yakoubi, C. Joly, J. Lesrel, E. Rampnoux IPN, Orsay, France A. Bosotti, R. Paparella, P. Pierini INFN/LASA, Segrate (MI), Italy
	Funding: This work is being supported by the European Atomic Energy Community’s EURATOM) Seventh Framework Programme under grant agreement n°269565(MAX project). The MYRRHA (“Multi-purpose Hybrid Research reactor for High-tech Applications”) project aims at the construction of a new flexible fast spectrum research reactor. This reactor will operate as an Accelerator Driven System demonstrator. The criticality will be sustained by an external spallation neutron flux; produced thanks to a 600 MeV high intensity proton beam. This CW beam will be delivered by a superconducting linac which must fulfil very stringent reliability requirements. In this purpose, the accelerator design is based on a redundant and fault-tolerant scheme to enable the rapid mitigation of RF failures. To carry out “real scale” reliability-oriented experiments a prototype of cryomodule was developed by INFN Milano and installed at IPN Orsay. The module holds a 700 MHz 5-cell elliptical cavity (βg = 0.47) equipped with its blade frequency tuner. Several tests were carried out to commission the experimental set-up. We review here the obtained results and the lessons learnt by operating this module, as well as the on-going developments.

MOP065	Consolidated Design of the 17 MeV Injector for MYRRHA	cavity, proton, rfq, cryomodule	274
	D. Mäder, D. Koser, H. Podlech, A. Schempp IAP, Frankfurt am Main, Germany
	Funding: Project supported by the EU, FP7 MAX, contract No. 269565 and BMBF, contract No. 06FY7102. The MYRRHA research reactor will be an Accelerator Driven System, which demands a 2.4 MW proton beam delivered by a 600 MeV cw operated linac. The beam dynamics design of the injector has been consolidated to fulfil the requirements with respect to beam losses and quality. After a 4-rod-RFQ, four 7-gap room temperature CH cavities with a constant phase and an effective voltage of 750 keV are used to reach 4.3 MeV. Then the proton beam is accelerated to 18 MeV using six superconducting 5-gap Nb CH structures with a constant beta profile. With reducing the gradient and adjusting the phase of the twelfth CH structure the originally demanded 17 MeV can be delivered, too. Every SC CH cavity is cooled down to 2K with liquid helium in a separate cryo module. The new geometric design of the SC CH cavities improves the rigidity and reduces the electric peak field.

MOP066	Development of Compact Cryomodules Housing HWRs for High-intensity SC CW Linacs	cavity, cryomodule, niobium, proton	277
	P.N. Ostroumov, Z.A. Conway, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.H. Kim, S.V. Kutsaev, R.C. Murphy, B. Mustapha, T. Reid ANL, Argonne, USA D. Berkovits Soreq NRC, Yavne, Israel S. Nagaitsev Fermilab, Batavia, USA
	Funding: This work was supported by the U.S. Department of Energy, under Contracts No. DE-AC02-06CH11357, DE-AC02-76CH03000 and ANL WFO No. 85Y47. Acceleration of high-intensity light-ion beams immediately after an RFQ requires a compact accelerating and focusing lattice with a high packing factor. We have developed a cryomodule which satisfies this requirement with eight accelerating-focusing periods for Project X at FNAL. Each focusing period consist of a 162.5-MHz SC HWR, a SC solenoid and a beam position monitor. The highly optimized EM parameters of the cavity were achieved by using double conical, hour glass like, inner and outer conductors. This design is also favorable for the beam dynamics because the short focusing periods which helps to better control the beam quality. All sub-systems of the cryomodule, except the vacuum-vessel, are in advanced stages of prototyping and testing. A similar concept has been developed for the design of several cryomodules for a 20 MeV/u proton/deuteron 200 kW linac at SNRC. These cryomodules house two types of 176 MHz half-wave resonators and require only modest modifications for the application. This paper will discuss the status of the FNAL cryomodule design and sub-system fabrication and its impact on future HWR cryomodule such as the SNRC project.

MOP067	Results From Initial Tests of the 1st Production Prototype β=0.29 and β=0.53 HWR Cavities for FRIB	cavity, target, cryomodule, vacuum	280
	J.P. Ozelis, C. Compton, K. Elliott, M. Hodek, M. Leitner, I.M. Malloch, D. Miller, S.J. Miller, D. Norton, R. Oweiss, J. Popielarski, L. Popielarski, A.P. Rauch, K. Saito, G.J. Velianoff, D.R. Victory FRIB, East Lansing, USA
	Funding: Work supported by US DOE Cooperative Agreement DE-SC0000661 and Michigan State University The first prototypes of the β=0.53 and β=0.29 HWR production design cavities for FRIB were fabricated early this year by Roark Manufacturing Company and delivered to MSU. These cavities have undergone an extensive evaluation program to verify both mechanical and RF performance before proceeding with fabrication of a pre-production run of 10 cavities. Results from physical inspections, warm RF measurements, chemical processing, and cryogenic vertical testing will be presented.

MOP068	NGLS Linac Design	cryomodule, cavity, cryogenics, controls	286
	R.P. Wells, J.M. Byrd, J.N. Corlett, L.R. Doolittle, P. Emma, A. Ratti LBNL, Berkeley, California, USA C. Adolphsen, C.D. Nantista SLAC, Menlo Park, California, USA D. Arenius JLAB, Newport News, Virginia, USA C.M. Ginsburg, T.J. Peterson Fermilab, Batavia, USA
	Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 The Next Generation Light Source (NGLS) is a design concept for a multibeamline soft x-ray FEL array powered by a CW superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. This paper describes the concepts for the cavity and cryostat design operating at 1.3 GHZ and based on minimal modifications to the design of ILC cryomodules, This leverages the extensive experience derived from R&D that resulted in the ILC design. Due to the different nature of the two applications, particular attention is given now to high loaded Q operation and microphonics control, as well as high reliability and expected up time. The work describes the design and configuration of the linac, including choice of gradient, possible modes of operation, cavity design and RF power, as well as the consequent requirements for the cryogenic system.

MOP069	Precise Measurement of Superconducting Cavity Movement in Cryomodule by the Position Monitor Using White Light Interferometer	target, cryomodule, cavity, superconducting-cavity	291
	H. Sakai, T. Aoto, K. Enami, T. Furuya, M. Sato, K. Shinoe, K. Umemori KEK, Ibaraki, Japan E. Cenni Sokendai, Ibaraki, Japan K. Hayashi, K. Kanzaki Tokyo Seimitsu Co. Ltd, Ibaraki, Japan M. Sawamura JAEA, Ibaraki-ken, Japan
	Alignment of Superconducting cavity is one of the important issues for linear collider and/or future light source like ERL and X-FEL. To measure the cavity displacement under cooling to Liq He temperature more precisely, we newly developed the position monitor by using white light interferometer. This monitor is based on the measurement of the interference of light between the measurement target and the reference point. It can measure the position from the outside of the cryomodule. We applied this monitor to the main linac cryomodule of Compact ERL and successfully measured the displacement during 2K cooling with the resolution of 10 micron

MOP071	Record Quality Factor Performance of the Prototype Cornell ERL Main Linac Cavity in the Horizontal Test Cryomodule	cavity, cryomodule, experiment, higher-order-mode	300
	N.R.A. Valles, R.G. Eichhorn, F. Furuta, G.M. Ge, D. Gonnella, D.L. Hall, Y. He, K.M.V. Ho, G.H. Hoffstaetter, M. Liepe, T.I. O'Connel, S. Posen, P. Quigley, J. Sears, V. Veshcherevich Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: Supported by NSF grant DMR-0807731 Future SRF linac driven accelerators operated in CW mode will require very efficient SRF cavities with high intrinsic quality factors Q at medium accelerating fields. Cornell has recently ﬁnished testing the fully equipped 1.3 GHz, 7-cell main linac cavity for the Cornell Energy Recovery Linac in a horizontal test cryomodule (HTC). Measurements characterizing the fundamental mode’s quality factor have been completed, showing record Q performance. In this paper, we present detailed quality factor vs gradient results for three HTC assembly stages. We show that the performance of an SRF cavity can be maintained when installed into a cryomodule, and that thermal cycling reduces residual surface resistance. We present world record results for a fully equipped multicell cavity in a cryomodule, reaching intrinsic quality factors at operating accelerating field of Q(E =16.2 MV/m, 1.8K) > 6·10¹⁰ and Q(E =16.2 MV/m, 1.6K) > 1.0·10¹¹, corresponding to a very low residual surface resistance of 1.1 nOhm.

MOP074	Design and Construction of the Main Linac Cryomodule for the Energy Recovery Linac Project at Cornell	cryomodule, vacuum, alignment, cryogenics	308
	R.G. Eichhorn, B. Bullock, J.V. Conway, Y. He, T.I. O'Connel, P. Quigley, D.M. Sabol, J. Sears, E.N. Smith, V. Veshcherevich Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Cornell University has been designing and building superconducting accelerators for various applications for more than 50 years. Currently, an energy-recovery linac (ERL) based synchrotron-light facility is proposed making use of the existing CESR facility. As part of the phase 1 R&D program funded by the NSF, critical challenges in the design were addressed, one of them being a full linac cryo-module. It houses 6 superconducting cavities- operated at 1.8 K in continuous wave (CW) mode - with individual HOM absorbers and one magnet/ BPM section. Pushing the limits, a high quality factor of the cavities and high beam currents (2*100 mA)are targeted. We will present the design of the main linac module (MLC) being finalized recently, its cryogenic features and report on the status of the fabrication which started in late 2012

MOP081	Preliminary Studies of the Cryogenic Refrigerator and Distribution Systems for the MYRRHA Proton Linac	cryogenics, cryomodule, proton, operation	331
	T. Junquera, N.R. Chevalier, J.P. Thermeau Accelerators and Cryogenic Systems, Orsay, France L. Medeiros Romão, D. Vandeplassche SCK•CEN, Mol, Belgium H. Saugnac IPN, Orsay, France
	Funding: Work supported by the EU, FP7 MAX contract number 269565 In the framework of recent European programs (FP6-Eurotrans, FP7-MAX), the SC proton Linac for the MYRRHA project (associating an accelerator to a subcritical nuclear reactor, to be installed in the SCK•CEN at Mol-Belgium), has been extensively studied and optimized to reach strict requirements in beam power and reliability as needed for this ADS demonstrator. The linac, composed of 150 SC cavities (CH, spoke and elliptical) installed in 60 cryomodules, operates at 2K, delivering a beam power of 2.5 MW (600 MeV, 4 mA) in CW mode, will be installed in a tunnel of 240 m length. In this paper we present the evaluation of the cryogenic power requirements, a preliminary architecture of the cryogenic refrigerator system including all its major components, and preliminary proposals for the cryofluids distribution along the SC linac.

MOP082	Development and Test of a New Cryostat Module for the Injector of the S-DALINAC*	electron, operation, vacuum, cavity	334
	T. Kürzeder, J. Conrad, F. Hug, N. Pietralla, A. Richter, S.T. Sievers TU Darmstadt, Darmstadt, Germany R.G. Eichhorn Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: *This work is supported by the DFG through the Collaborative Research Center SFB 634. The present injector of the superconducting Darmstadt electron linear accelerator S-DALINAC provides an electron beam of up to 10 MeV kinetic energy and up to 60 μA current in continuous wave operation. A new cryostat module has been constructed to replace the actual one in order to provide higher beam energies of up to 14 MeV and currents of up to 250 μA for nuclear resonance fluorescence experiments at the Darmstadt High Intensity Photon Setup (DHIPS). As before two 20-cell superconducting microwave cavities will be operated at an acceleration frequency of 3 GHz in a liquid helium bath at 2 K. For the injector upgrade two new elliptical 20-cell niobium cavities were also manufactured and in addition a third spare one. The rf power is transferred to the cavities by an also newly developed waveguide-transition line and input couplers. We report on the construction of the cryostat module and its components and present the results of a first cooling-down procedure.

MOP085	Status of the Superconducting Proton Linac (SPL) Cryomodule	cavity, vacuum, cryogenics, operation	345
	V. Parma, R. Bonomi, O. Capatina, J.K. Chambrillon, E. Montesinos, K.M. Schirm, A. Vande Craen, G. Vandoni, R. van Weelderen CERN, Geneva, Switzerland G. Devanz CEA/IRFU, Gif-sur-Yvette, France P. Duchesne, P. Duthil, S. Rousselot IPN, Orsay, France
	The Superconducting Proton Linac (SPL) is an R&D effort conducted by CERN in partnership with other international laboratories, aimed at developing key technologies for the construction of a multi-megawatt proton linac based on state-of-the-art SRF technology. Such an accelerator would serve as a driver in new physics facilities for neutrinos and/or radioactive ion beams. Amongst the main objectives of this effort, are the development of 704 MHz bulk niobium β=1 elliptical cavities (operating at 2 K and providing an accelerating field of 25 MV/m) and the test of a string of cavities integrated in a machine-type cryo-module. In an initial phase, only four out of the eight cavities of the SPL cryo-module will be tested in a half- length cryo-module developed for this purpose, which nonetheless preserves the main features of the full size machine. This paper presents the final design of the cryo-module and the status of the construction of the main cryostat parts. Preliminary plans for the assembly and testing of the cryo-module at CERN are presented and discussed.

MOP086	Integration, Commissioning and Cryogenics Performance of the ERL Cryomodule Installed on ALICE-ERL Facility at STFC Daresbury Laboratory, UK	cryomodule, cryogenics, SRF, HOM	349
	S.M. Pattalwar, R.K. Buckley, P.A. Corlett, P. Goudket, A.R. Goulden, A.J. May, P.A. McIntosh, A.E. Wheelhouse STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom S.A. Belomestnykh BNL, Upton, Long Island, New York, USA A. Büchner, F.G. Gabriel, P. Michel HZDR, Dresden, Germany E.P. Chojnacki, J.V. Conway, R.G. Eichhorn, G.H. Hoffstaetter, M. Liepe, H. Padamsee, P. Quigley, J. Sears, V.D. Shemelin Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA M.A. Cordwell, T.J. Jones, L. Ma, A.J. Moss, J. Strachan STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom J.N. Corlett, D. Li, S.M. Lidia LBNL, Berkeley, California, USA T. Kimura Stanford University, Stanford, California, USA R.E. Laxdal TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada J.K. Sekutowicz DESY, Hamburg, Germany T.J. Smith SLAC, Menlo Park, California, USA
	On successful assembly and preliminary testing of an optimised SRF cryomodule for application on ERL accelerators, which is being developed through an international collaboration the cryomodule has been installed on the 35 MeV ALICE (Accelerators and Lasers in Combined Experiments) Energy Recovery Linac (ERL) facility at STFC Daresbury Laboratory. Existing cryogenic infrastructure has a capacity to deliver approximately 120 W cooling power at 2 K, but the HOM (Higher Order Mode) absorbers, the thermal intercepts for the high power RF couplers and the radiation shield in the cryomodule are designed to be cooled (to 5 K and 80 K) with gaseous helium instead of liquid nitrogen. As a result the cryogenic infrastructure for ALICE had to be modified to meet these additional requirements. In this paper we describe our experience with the process of integration and the cryogenic commissioning, and present some initial results.

MOP090	Feasibility of Using Conductively Cooled Magnets in Cryomodules of Superconducting Linacs	radiation, cryomodule, focusing, solenoid	361
	I. Terechkine, S. Cheban, T.H. Nicol, V. Poloubotko, D.A. Sergatskov Fermilab, Batavia, USA
	While trying to find an optimal way to configure cryomodule for the low energy part of a high-current, high-power superconducting linac, an option of using conductively cooled superconducting focusing lenses was evaluated. As part of this evaluation, several tests were made using existing test cryostat. The cryostat was modified by adding current feed-throughs and two conductively cooled current leads, each equipped with heat sinks at the temperatures of liquid nitrogen and liquid helium. A superconducting magnet was mounted inside the cryostat on an individual heat sink, and thermometers were installed on the leads, heat sinks, and on the magnet’s winding. In this report we provide some details of the heat exchangers’ designs, compare predicted and measured temperature distribution along the leads, and analyze results of the winding temperature measurements.

TUP026	Performance of a FNAL Nitrogen Treated Superconducting Niobium Cavity at Cornell	cavity, niobium, SRF, superconductivity	475
	D. Gonnella, M. Liepe Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA A. Grassellino Fermilab, Batavia, USA
	Funding: NSF In many tests of superconducting cavities, the performance of the cavity in the medium field region will be limited by medium field Q slope. For projects such as the proposed Cornell Energy Recovery Linac, high Q operation at medium fields is necessary to meet specifications for efficient CW cavity operation. A single cell cavity was prepared by Fermilab by electropolishing it and baking it at 1000°C with 1x10^-2 Torr of Nitrogen, and subsequently tested at Cornell. The cavity displayed an increase in Q at medium fields between 5 and 20 MV/m at 2.0 K, opposite of the usual medium field Q slope. The material properties of this cavity were studied and correlated with performance. This analysis helps to better understand how to overcome medium field Q slope and improve cavity performance in future CW SRF machines such as the Cornell ERL.

TUP027	High Q0 Studies at Cornell	cavity, niobium, SRF, factory	478
	D. Gonnella, M. Liepe Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: NSF The construction and preparation of superconducting RF cavities with very high quality factors is very advantageous for future particle accelerators operating in CW mode. Until recently, the highest quality factors measured in SRF cavities were on the order of 10¹¹. A Cornell ERL single-center-cell cavity was prepared with BCP and a five day heat treatment at 1000°C. Following this treatment, the cavity was tested and achieved a record high intrinsic quality factor of 2.9·10¹¹ at 1.4 K, corresponding to a very small residual resistance of (0.35±0.10) nOhm. This cavity was then given a series of BCP’s of 5, 75, and 200 μm and retested. Material properties were extracted from the data hinting at a very low mean free path of the niobium. In this paper we discuss the unusual material properties of the surface layer of the cavity and their implication for the RF performance of the cavity.

TUP044	Surface Processing Facilities for Spoke Cavities at IHEP	cavity, recirculation, superconductivity, LLRF	508
	J.P. Dai, H. Li, L.H. Li, Q.Y. Wang, J. Zhang IHEP, Beijing, People's Republic of China P. Sha Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China
	Funding: Work supported by the "Strategic Priority Research Program" of CAS, under Grant No. XDA03020600 The China ADS injector I program is building a CW 10MeV Superconducting proton linac at IHEP. To develop the superconducting spoke-type cavities incorporated in this linac, a set of new surface processing facilities were built and successfully used to treat the Spoke012 prototype cavities. In this paper, we present the design, fabrication and operation of these facilities, including BCP, HPR and UPW, etc.

TUP057	Plasma Processing R&D for the SNS Superconducting Linac RF Cavities	plasma, cavity, cryomodule, niobium	551
	M. Doleans, W. Blokland, M.T. Crofford, D.L. Douglas, M.P. Howell, S.-H. Kim, P.V. Tyagi ORNL, Oak Ridge, Tennessee, USA R. Afanador, J.A. Ball, B. DeGraff, B.S. Hannah, S.W. Lee, C.J. McMahan, J. Saunders ORNL RAD, Oak Ridge, Tennessee, USA
	Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE The Spallation Neutron Source routinely operates with a proton beam power of 1 MW on its production target. A plan to reach the design 1.4 MW within a few years is in place* and relies on increasing the ion beam current, pulse length and beam energy in the linac. The increase in beam energy from the present 930 MeV to 1 GeV will require an increase of approximately 15% in the accelerating gradient of the superconducting linac high-beta cryomodules. In-situ plasma processing was identified as a promising technique** to reduce electron activity in the SNS superconducting cavities and increase their accelerating gradient. R&D on plasma processing aims at deploying the new in-situ technique in the linac tunnel by 2016. Overall plan and current status of the plasma processing R&D will be presented. * NScD Five year plan 2012-2016, SNS-NSCD-EXE-PN-0001, R00, ORNL ** S-H Kim et al., “R&D Status for In-Situ Plasma Surface Cleaning of SRF Cavities at Spallation Neutron Source”, PAC 2011 Proceedings

TUP069	The Copper Substrate Developments for the HIE-ISOLDE High-Beta Quarter Wave Resonator	cavity, electron, cryogenics, operation	596
	L. Alberty, G. Arnau-Izquierdo, I. Aviles Santillana, S. Calatroni, O. Capatina, A. D'Elia, G. Foffano, Y. Kadi, P. Moyret, K.M. Schirm, T. Tardy, W. Venturini Delsolaro CERN, Geneva, Switzerland A. D'Elia UMAN, Manchester, United Kingdom
	A new linac using superconducting quarter-wave resonators (QWR) is under construction at CERN in the framework of the HIE-ISOLDE project. The QWRs are made by Niobium sputtered on a bulk Copper substrate. The working frequency at 4.5 K is 101.28 MHz and they will provide 6 MV/m accelerating gradient on the beam axis with a total maximum power dissipation of 10 W. The properties of the cavity substrate have a direct impact on the final cavity performance. The Copper substrate has to ensure an optimum surface for the Niobium sputtered layer. It has also to fulfill the required geometrical tolerances, the mechanical stability during operation and the thermal performance to optimally extract the RF dissipated power on cavity walls. The paper presents the mechanical design of the high β cavities. The procurement process of the Copper raw material is detailed, including specifications and tests. The manufacture sequence of the complete cavity is then explained and the structural and thermo-mechanical behavior during the tests performed on a prototype cavity is discussed. The industrialization strategy is presented in view of final production of the cavities.

TUP085	Study of NbTi Welded Parts	niobium, cavity, laser, plasma	659
	N. Bazin, C.Z. Antoine CEA/DSM/IRFU, France C. B. Baumier, G. Martinet IPN, Orsay, France F. F. Fortuna CSNSM, ORSAY CAMPUS, France J.-B. Sirven Commisariat à l'Energie Atomique (CEA/DEN/DPC), Direction de l'Energie Nucléaire, Gif-sur-Yvette, France
	Due to its properties, niobium-titanium alloy is widely used to manufacture the flanges of superconducting niobium accelerating cavities. The material hardness is compliant to provide UHV-tight connections with aluminum gaskets or spring-type gaskets (Helicoflex). And the alloy can be directly welded to the niobium. The paper will present the surface analysis made on NbTi samples after the chemical treatment and on a Nb / NbTi weld.

TUP087	RF Test Results of the first Nb3Sn Cavities Coated at Cornell	cavity, niobium, SRF, operation	666
	S. Posen, M. Liepe Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	As an alternative material to niobium for SRF cavities in particle accelerators, Nb3Sn presents two significant advantages. With a Tc of 18 K, it has a very small surface resistance at a given temperature, leading to a significant reduction in cryogenic costs; and with a predicted Hsh of nearly 400 mT, it has the potential to produce cavities with higher gradients and therefore shorter high energy linacs. Recently, two 1.3 GHz cavities have been fabricated and coated with Nb3Sn at Cornell. Tests of these first cavities have produced encouraging results, including a very high Tc and some very high-performing surface regions. These cavity results as well as new results of samples studied using TEM will be presented.

TUP091	Field Emission Measure During cERL Main Linac Cryomodule High Power Test in KEK	cavity, radiation, electron, cryomodule	678
	E. Cenni Sokendai, Ibaraki, Japan K. Enami, T. Furuya, H. Sakai, M. Satoh, K. Shinoe, K. Umemori KEK, Ibaraki, Japan M. Sawamura JAEA, Ibaraki-ken, Japan
	A compact Energy Recovery Linac (cERL) is under construction in KEK in order to proof the performance of the key components required for the future ERL project in KEK. The main linac L-band cavities were assembled and tested in the cryomodule under high power operation, during the test information concerning field emission were gathered by means of PIN diodes rings and NaI scintillator located at the cavities ends. The data were analyzed by means of simulations, taking into account the cavities operating conditions and interaction between the accelerated electrons and the cavity surface. The resulting information are used to deduce a possible emitter location, determining if there is any change in the cavities performance with respect to the last vertical test they undertook. With PIN diode is possible to observe the radiation pattern produced by field emission, inferring the meridian where the emitter belongs. On the other hand the bremsstrahlung spectra recorded with the scintillator allow an estimation of the cavity cell where the emitter is located.

TUP116	Quench field and Location in Vertical Tests at KEK-STF	cavity, linear-collider, accelerating-gradient, cryomodule	751
	Y. Yamamoto, E. Kako, T. Shishido KEK, Ibaraki, Japan
	Many vertical tests have been done for the ILC and ERL at KEK-STF since 2008. T-mapping system (fixed type) was equipped at every vertical test, and quench location was identified completely. Every quench location at quench field will be presented in this paper.

WEIOA03	Nb Sputtered Quarter Wave Resonators for the HIE-ISOLDE	cavity, cathode, niobium, vacuum	767
	W. Venturini Delsolaro, S. Calatroni, A. D'Elia, B. Delaup, N.M. Jecklin, Y. Kadi, P. Maesen, I. Mondino, A. Sublet, M. Therasse CERN, Geneva, Switzerland A. D'Elia UMAN, Manchester, United Kingdom D.A. Franco Lespinasse, G. Keppel, V. Palmieri, S. Stark INFN/LNL, Legnaro (PD), Italy
	The HIE-ISOLDE superconducting linac will be based on quarter wave resonators (QWRs), made by Niobium sputtering on Copper. The operating frequency at 4.5 K is 101.28 MHz and the required performance for the high beta cavity is 6 MV/m accelerating field for 10 W maximum power dissipation. These challenging specifications were recently met at CERN at the end of a vigorous development program. The paper reports on the progress of the cavity RF performance with the evolution of the sputtering process; it equally illustrates the parallel R&D which is ongoing at CERN and at INFN in the quest for even higher performances.
	Slides WEIOA03 [14.564 MB]

WEIOD01	Review of Magnetic Shielding Designs of Low-Beta Cryomodules	solenoid, cavity, cryomodule, shielding	800
	R.E. Laxdal TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	It is well known that superconducting cavities can trap magnetic flux while cooling through transition. The trapped flux adds to the residual rf surface resistance. For this reason magnetic shielding is added to the cryomodules to shield the cavities from the environmental magnetic field. The low beta portion of many superconducting hadron linear accelerators, either in operation or in production, includes cryomodules containing one or more high field superconducting solenoids. The operation of a high field solenoid in close proximity to a cavity adds a level of complexity to the cryomodule design considerations. The paper will summarize the various techniques that can be employed to reduce the risk of magnetic pollution from internal solenoids.
	Slides WEIOD01 [10.342 MB]

WEIOD02	Magnetic Shielding: Our Experience with Various Shielding Materials	shielding, cryogenics, superconducting-RF, simulation	808
	M. Masuzawa, A. Terashima, K. Tsuchiya KEK, Ibaraki, Japan A. Daël, O. Napoly, J. Plouin CEA/DSM/IRFU, France
	Magnetic shielding is a key technology for superconducting RF cavities. The tolerance of the ambient magnetic field depends on factors such as the operating RF frequency and acceleration gradient, but it can be as small as a few mG. Some high-Ni-content alloys, such as Cryperm 10 or Cryophy, which are claimed to maintain high permeability at cryogenic temperatures where superconducting cavities are operated, are commercially available at present and are used for magnetic shielding of superconducting cavities at many laboratories. Permeability measurements were made in order to understand the characteristics of such materials at both room and cryogenic temperatures, and the results will be used as a database for designing magnetic shields. It was found that the catalog performance of such materials was not always reproduced in the measurements. Some degradation was observed which depended on how the material was handled. The results of investigation into possible causes for the performance degradation of the shielding material at cryogenic temperature will be presented, along with permeability measurement results for various materials at different temperatures.
	Slides WEIOD02 [8.475 MB]

THIOA02	The Challenge to Assemble 100 Cryomodules for the European E-XFEL	cryomodule, cavity, controls, vacuum	816
	C. Madec CEA, Gif-sur-Yvette, France S. Berry, J.-P. Charrier, M. Fontaine, Y. Gasser, O. Napoly, C.S. Simon, T.V. Vacher, B. Visentin CEA/DSM/IRFU, France P. Charon, C. Cloué, G. Monnereau, J.L. Perrin, D. Roudier, Y. Sauce, T. Trublet CEA/IRFU, Gif-sur-Yvette, France
	As In-Kind contributor to the E-XFEL project, CEA is committed to the integration on the Saclay site of the 100 cryomodules (CM) of the superconducting linac as well as to the procurement of miscellaneous parts including 31 cold beam position monitors (BPM) of the re-entrant type. The assembly infrastructure has been renovated from the previous Saturne Synchrotron Laboratory facility: it includes a 200 m2 clean room complex with 112 m2 under ISO4, 1325 m2 of assembly platforms and 400 m2 of storage area. In parallel, CEA has conducted industrial studies and three cryomodule assembly prototyping both aiming at preparing the industrial file, the quality management system and the commissioning of the assembly plant, tooling and control equipment. In 2012, the contract of the integration has been awarded to ALSYOM. The first pre-series modules have been assembled and are being tested at DESY. This paper will present the challenges of the module integration from the preparation phase to the industrial phase.
	Slides THIOA02 [17.641 MB]

THIOA05	Optimization of SRF Linacs	cryomodule, cavity, cryogenics, operation	830
	T. Powers JLAB, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. This work describes preliminary results of a new software tool that allows one to vary parameters and understand the effects on the optimized costs of construction plus 10 year operations of an SRF linac, the associated cryogenic facility, and controls, where operations includes the cost of the electrical utilities but not the labor or other costs. It derives from collaborative work done with staff from Accelerator Science and Technology Centre, Daresbury, UK several years ago while they were in the process of developing a conceptual design for the New Light Source project. The initial goal was to convert a spread sheet format to a graphical interface to allow the ability to sweep different parameter sets. The tools also allow one to compare the cost of the different facets of the machine design and operations so as to better understand the tradeoffs. More recent additions to the software include the ability to save and restore input parameters as well as to adjust the Qo versus E parameters in order to explore the potential costs savings associated with doing so.
	Slides THIOA05 [2.712 MB]

THIOB01	CEBAF Upgrade: Cryomodule Performance and Lessons Learned	cryomodule, cavity, vacuum, controls	836
	M.A. Drury, J. Hogan, C. Hovater, L.K. King, H. Park, J.P. Preble, R.A. Rimmer, H. Wang, M. Wiseman JLAB, Newport News, Virginia, USA G.K. Davis, C.E. Reece JLab, Newport News, Virginia, USA F. Marhauser Muons, Inc, Illinois, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract DE-AC05-06OR23177. The Thomas Jefferson National Accelerator Facility is currently engaged in the 12 GeV Upgrade Project. The goal of the 12 GeV Upgrade is a doubling of the available beam energy of the Continuous Electron Beam Accelerator Facility (CEBAF) from 6 GeV to 12 GeV. The increase in beam energy will largely be due to the addition of ten C100 cryomodules and the associated RF in the CEBAF linacs. These cryomodules are designed to deliver 100 MeV per cryomodule. Each C100 cryomodule contains a string of eight seven-cell, electro-polished, superconducting RF cavities. While an average performance of 100 MV is needed to achieve the overall 12 GeV beam energy goal, the actual performance goal for the cryomodules is an average energy gain of 108 MV to provide operational headroom. All ten of the C100 cryomodules are installed in the linac tunnels and are on schedule to be commissioned by September 2013. Commissioned performance has ranged from 104 MV to 118 MV. In May, 2012, a test of an early C100 achieved 108 MV with full beam loading. This paper will discuss the performance of the C100 cryomodules along with operational challenges and lessons learned for future designs. The U.S. Govt. retains a non-exclusive, paid-up,irrevocable,world-wide license to publish or reproduce this manuscript.
	Slides THIOB01 [2.534 MB]

THIOB02	High Q Cavities for the Cornell ERL Main Linac	cavity, cryomodule, SRF, HOM	844
	R.G. Eichhorn, B. Bullock, B. Clasby, B. Elmore, F. Furuta, A. Ganshin, G.M. Ge, D. Gonnella, D.L. Hall, Y. He, K.M.V. Ho, G.H. Hoffstaetter, J.J. Kaufman, M. Liepe, T.I. O'Connel, S. Posen, P. Quigley, J. Sears, V.D. Shemelin, E.N. Smith, V. Veshcherevich Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	While SRF research for linear colliders was focused on achieving high gradients, Cornell’s proposal for an energy recovery linac (ERL) demanded for low cw losses. Starting several years ago, a high-Q R&D phase was launched that led to remarkable results recently: A fully dressed cavity (7 cells, 1.3 GHz) with side-mounted input coupler and beamline HOM absorbers achieved a Q of 3.5·10¹⁰ ((16 MV/m, 1.8 K). This talk will review the staged approach we have chosen in testing a single cavity in a horizontal short cryomodule (HTC), report results on each step and conclude on our findings about preserving high Q from vertical testing. We also discuss the production of six additional cavities as we progress toward constructing a full 6-cavity cryomodule as a prototype for Cornell’s main linac module
	Slides THIOB02 [8.378 MB]

THIOC01	Low Beta Cavity Development for an ATLAS Intensity Upgrade	cavity, cryomodule, niobium, ion	850
	M.P. Kelly, Z.A. Conway, S.M. Gerbick, M. Kedzie, S.H. Kim, R.C. Murphy, B. Mustapha, P.N. Ostroumov, T. Reid ANL, Argonne, USA
	The set of seven new 72 MHz quarter wave SC (QWR) cavities has been completed and is being installed in the ATLAS heavy-ion accelerator at Argonne. The aim is to provide at least 17.5 MV accelerating potential with large acceptance and minimal beam losses for high intensity ion beams. The cavity electromagnetic design uses optimizations not used before with QWR including a large taper on both the inner and outer conductors in order to reduce surface fields and make efficient use of space along the beam line. Electropolishing (EP) on the finished cavities with integral helium jacket and no demountable RF joints has been performed, and is the first for any low beta SC cavity. This type of EP, adapted from Argonne systems for the linear collider effort, appears to have a large benefit in terms of the average quench field which range between 103-165 mT for five QWR tested to date. Cavity residual resistances at the proposed operating point of ~70 mT are low, clustering close to a value of ~2nOhm. Additional technical details including the almost exclusive use of wire EDM for niobium fabrication and a new CW 4 kW RF power coupler are presented.
	Slides THIOC01 [10.152 MB]

THIOC02	High Power CW Tests of cERL Main-Linac Cryomodule	cryomodule, cavity, HOM, alignment	855
	H. Sakai, K. Enami, T. Furuya, M. Satoh, K. Shinoe, K. Umemori KEK, Ibaraki, Japan E. Cenni Sokendai, Ibaraki, Japan M. Sawamura JAEA, Ibaraki-ken, Japan
	A main linac cryomodule have been constructed for Compact ERL project. It contains two 9-cell cavities, mounted with HOM absorbers and input couplers. After cavity string assembly, they were installed into the vacuum vessel of the cryomodule. It was placed inside radiation shield of cERL and connected to a refrigerator system. The cryomodule was successfully cooled down to 2K and low power and high power measurements were carried out.
	Slides THIOC02 [12.842 MB]

THIOD01	SRF Cavities for ADS Project in China	cavity, SRF, proton, operation	868
	Y. He, W.M. Yue, S.H. Zhang IMP, Lanzhou, People's Republic of China J.P. Dai, Z.Q. Li, Z.C. Liu, W.M. Pan IHEP, Beijing, People's Republic of China X.Y. Lu PKU, Beijing, People's Republic of China
	The driver linac for ADS project in China is full superconducting downstream of Radio Frequecy Quadrupole Accelerator. It is a key technology R&D stage of the project from 2011 to 2015. Superconducting HWR, Spoke, and elliptical cavities are all involved in the project. The prototypes of 162.5 MHz HWR010, 325 MHz Spoke012, 325 MHz Spoke021, 325 MHz Spoke040, and 650 MHz elliptical 063 are being developed at IMP and IHEP in China. A small number of HWR010 and Spoke012 have been produced and vertically tested. The first prototype of Spoke021 were tested too. The design, performances, fabrication, suface processing, and testing of all cavities will be presented in the talk. The design improvement of the cavities in the future will also be discussed.
	Slides THIOD01 [13.465 MB]

THIOD02	Faced Issues in ReA3 Quarter-Wave Resonators and Their Successful Resolution	cavity, vacuum, cryomodule, operation	873
	A. Facco NSCL, East Lansing, Michigan, USA C. Compton, J.L. Crisp, K. Elliott, A. Facco, M. Hodek, M.J. Johnson, M. Leitner, I.M. Malloch, D. Miller, S.J. Miller, D. Morris, D. Norton, R. Oweiss, J.P. Ozelis, J. Popielarski, L. Popielarski, K. Saito, N.R. Usher, G.J. Velianoff, D.R. Victory, J. Wei, K. Witgen, Y. Xu, S. Zhao FRIB, East Lansing, Michigan, USA A. Facco INFN/LNL, Legnaro (PD), Italy
	Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. The 80.5 MHz, β=0.085 QWR production cavities for the ReA3 project at MSU have initially shown puzzling behavior and unexpected lack of performance. This was due to a combination of design problems and subtle mechanical effects which have been pointed out during a brief but intense testing campaign made by the FRIB SRF group. The same cavities could be eventually refurbished and brought to performance well above original specifications. This work will be presented with emphasis to the technical problems encountered, their diagnosis and the adopted solutions.
	Slides THIOD02 [8.256 MB]

THIOD04	A Cold Tuner System With Mobile Plunger	cavity, simulation, insertion, cryomodule	884
	D. Longuevergne, S. Blivet, S. Bousson, N. Gandolfo, G. Martinet, G. Olry, H. Saugnac IPN, Orsay, France
	Tuner systems for accelerating cavities are required to compensate static and dynamic frequency perturbations during beam operation. In the case of superconducting cavities, these are commonly tuned by deforming the cavity wall in specific places of the geometry. Nevertheless, considering the mechanical properties and frequency versus displacement sensitivity of some structures, tuning by deformation doesn’t allow to meet the requirements. In these specific cases, inspired from the “room temperature technology”, an alternative tuning technique by insertion of a helium-cooled superconducting plunger can be considered and has been studied for several projects (IFMIF, ESS-BILBAO). Advantages and drawbacks of such solution will be discussed and the successful results on SPIRAL2 cryomodule developed at IPNO will be presented.
	Slides THIOD04 [4.938 MB]

THP001	Development of a Prototype SRF Cavity for the Proton Beam Utilization Facility at Nanjing University	cavity, HOM, SRF, proton	889
	S. An, P.P. Xue PLAI, Nanjing, People's Republic of China S.Q.X. Xu, H. Z. Zhang ADS-SRF, People's Republic of China P.P. Xue, L. Zhang Chang’an University, Chang'an, People's Republic of China Z.R. Zhang Nanjing University of Aeronautics and Astronautics, Jiangning, People's Republic of China
	Nanjing University has initiated the new technology development in the field of high-energy, charged-particle beam application and fundamental sciences. A high-current proton accelerator used for the new energy, new technology and fundamental science applications platform will be the near term goal at Nanjing University. For developing the superconducting RF linac for the proton beam utilization at Nanjing University, the first 6-cell, medium-beta prototype superconducting RF cavity has been fabricated and demonstrated using Chinese vendors only. The low-power test has been completed. The vertical test will be carried out soon.

THP003	Cold Measurements on the 325 MHz CH-Cavity	cavity, coupling, ion, operation	896
	M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger IAP, Frankfurt am Main, Germany M. Amberg HIM, Mainz, Germany
	Funding: GSI, BMBF Contr. No. 06FY7102, 06FY9089I At the Institute for Applied Physics (IAP), Frankfurt University, a sc 325 MHz CH-Cavity has been designed and built. This 7-cell cavity has a geometrical beta of 0.16 corresponding to a beam energy of 11.4 AMeV. The design gradient is 5 MV/m. Novel features of this resonator are a compact design, low peak fields, easy surface processing and high power coupling. After successful tests at Research Instruments (RI) and in Frankfurt the cavity was processed and cleaned at RI and power tests at 4K have been performed at the cryo lab in Frankfurt. In this paper these measurements will be presented.

THP006	A Superconducting 217 MHz CH Cavitiy for the CW Demonstrator at GSI	cavity, solenoid, cryomodule, ion	906
	F.D. Dziuba, M. Amberg, M. Busch, H. Podlech, U. Ratzinger IAP, Frankfurt am Main, Germany M. Amberg, K. Aulenbacher, W.A. Barth, V. Gettmann, S. Mickat HIM, Mainz, Germany K. Aulenbacher IKP, Mainz, Germany W.A. Barth, S. Mickat GSI, Darmstadt, Germany
	Funding: Work supported by HIM, GSI, BMBF Contr. No. 05P12RFRBL For a competitive production of new Super Heavy Elements (SHE) in the future a 7.3 AMeV superconducting (sc) continuous wave (cw) LINAC is planned at GSI. Currently, a cw demonstrator is going to be built up. The demonstrator consists of a sc 217 MHz Crossbar-H-mode (CH) cavity and two sc 9.5 T solenoids mounted in a horizontal cryostat. One major goal of the demonstrator project is to show the operation ability of sc CH cavity technology under a realistic accelerator environment. After first rf and cold tests the demonstrator will be tested with beam delivered by the GSI High Charge State Injector (HLI) in 2014.

THP007	Cornell's ERL Cavity Production	cavity, target, controls, cryomodule	909
	R.G. Eichhorn, B. Bullock, B. Clasby, B. Elmore, F. Furuta, G.H. Hoffstaetter, J.J. Kaufman, B.M. Kilpatrick, J. Sears, V.D. Shemelin Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA T. Kürzeder TU Darmstadt, Darmstadt, Germany
	The phase 1 R&D program launched in preparation to building a 5 GeV Energy Recovery Linac (ERL) at Cornell, a full main linac cryomodule is currently built, housing six 7-cell cavities. In order to control the beam break-up limit, the shape of the cavity was highly optimized and stringent tolerances on the cavity production were targeted. We will report on the details of the cavity production, the accuracy of the cups forming the individual cells, the trimming procedure for the dumbbells, the cavity tuning and final accuracy of the cavity concerning field flatness, resonant frequency and overall length within this small series production.

THP013	A New Cavity Design for Medium Beta Acceleration	cavity, cryomodule, target, impedance	920
	F.S. He, R.A. Rimmer, H. Wang JLAB, Newport News, Virginia, USA
	Funding: Work supported by DOE Heavy duty or CW, superconducting proton and heavy ion accelerators are being proposed and constructed worldwide. The total length of the machine is one of the main drivers in terms of cost. Thus HWR and spoke cavities at medium beta are usually optimized to achieve low surface field and high gradient. A novel accelerating structure at β=0.5 evolved from spoke cavity is proposed, with lower surface fields but slightly higher heat load. It would be an interesting option for pulsed and CW accelerators with beam energy of more than 200MeV/u.

THP016	DEVELOPMENT OF THE SUPERCONDUCTING HALF WAVE RESONATOR FOR INJECTOR II IN C-ADS	cavity, niobium, simulation, proton	923
	W.M. Yue, W. Chang, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, F.F. Wang, R.X. Wang, M.X. Xu, C. Zhang, S.H. Zhang, S.X. Zhang IMP, Lanzhou, People's Republic of China
	The Development of the Half Wave Resonator (HWR010) is based on the China ADS. The HWR010 operates at 162.5 MHz and can provide more than 0.78 MV of accelerating voltage per cavity for proton withβopt=0.10. We have designed the HWR010 in 2011. A copper model has been fabricated to test the HWR fabrication procedure. Five HWR010s have been fabricated in 2012. The HWR010s has finished the vertical testing and the Q0 is 4·10⁸ at Epeak = 45 MeV/m, and one of the HWR010s has been vertical tested with helium vessel. The slow tuner and high power coupler for this HWR have been developed and tested.

THP018	Design of a Superconducting 352MHz Fully Jacketed Double-Spoke Resonator for the ESS-Bilbao Proton Linac	cavity, cryomodule, simulation, DTL	929
	T. Junquera Accelerators and Cryogenic Systems, Orsay, France F.J. Bermejo, J.L. Muñoz, A.V. Vélez ESS Bilbao, Bilbao, Spain P. Duchesne, G. Olry IPN, Orsay, France
	The baseline design for the ESS-Bilbao light-ion linear accelerator and neutron source (a facility compliant with the ESS-AB requirements) has been completed and the normal conducting section of the linac (RFQ and DTL) is at present under detailed design and construction. Starting at 50 MeV, it is proposed to follow this section with a superconducting section composed of double and triple spoke cavities grouped in cryomodules of 2 or 3 cavities reaching a maximum energy of 300 MeV. After an initial R&D program on spoke cavities with an aluminum model, detailed electromagnetic and mechanical studies of a beta 0.50, 352MHz, double spoke cavity were performed. The results of the calculations are presented in this paper. It is proposed to continue this development by the construction and test of the niobium cavities prototypes and initiating the study of a cryo-module with two cavities that could be tested with beam at the ESS-Bilbao facility.

THP019	1.3 GHz SRF Cavity Tests for ARIEL at TRIUMF	cavity, TRIUMF, HOM, SRF	933
	P. Kolb, P.R. Harmer, D. Kishi, A. Koveshnikov, C. Laforge, D. Lang, R.E. Laxdal, Y. Ma, B.S. Waraich, Z.Y. Yao, V. Zvyagintsev TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	The 1.3 GHz cavity test program at TRIUMF for the ARIEL eLINAC progressed into its next stage: Going from single cell cavity tests to demonstrate the operating Q and gradient for ARIEL can be reached at TRIUMF to nine cell cavity tests for production cavities. Single cell cavity tests at TRIUMF showed a comparable performance to a characterization done on the same cavity at FNAL last year. These single cell tests showed that the operating point for ARIEL of Q0 > 10¹⁰ at 10 MV/m during 2 K operation can be reached and exceeded at TRIUMF. To prepare for the first ARIEL nine cell cavity, a test with a TESLA nine cell cavity was done. This included frequency and field tuning, etching via BCP, HPR and assembly in a class 10 clean environment as well as modifications to the cryo assembly and upgrades to the 2 K pumping system. The performance of this TESLA cavity and the performance of first ARIEL nine cell cavity produced by PAVAC will be shown.

THP021	Design of the SSR021 Cavity for the Proton Accelerator Main Linac of China ADS	cavity, proton, simulation, target	939
	Z.Q. Li, Y.L. Chi, Q. Ma, W.M. Pan, Y. Sun, J.Y. Tang, Q.Y. Wang, B. Xu, X.Y. Zhang IHEP, Beijing, People's Republic of China Y. He, C. Zhang, S.H. Zhang, S.X. Zhang IMP, Lanzhou, People's Republic of China H.Y. Lin, P. Sha Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China
	China ADS is a high intensity proton machine based on CW superconducting technology. It includes two injectors and one main linac. The Institute of High Energy Physics (IHEP) and the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS), are responsible for developing the main linac together. This paper introduces the physics and mechanical design of the single spoke resonator (SSR021, beta021 cavity), which is used for first section of the main linac.

THP022	DEVELOPMENT OF A VERY LOW BETA SUPERCONDUCTING SINGLE SPOKE CAVITY FOR CHINA-ADS LINAC*	cavity, accelerating-gradient, LLRF, niobium	942
	H. Li, J.P. Dai, L.H. Li, H.Y. Lin, Q. Ma, W.M. Pan, Y. Sun, Q.Y. Wang, J. Zhang IHEP, Beijing, People's Republic of China H. Huang, P. Sha Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China
	Twelve very low Beta superconducting single spoke cavities whose Beta is only 0.12 (Spoke012) operating at 325MHz, are adopted in Injector I for China-ADS linac. This type of spoke cavity is believed to be one of the key challenges for its very low geometric Beta. So far, collaborated with Peking University and Harbin Institute of Technology, IHEP has designed, fabricated and tested the spoke012 prototype cavity successfully. This paper presents the details of the design, fabrication and vertical test results for Spoke012 prototype cavity.

THP028	The Research on Spoke 0.40 Cavity	cavity, simulation, proton, superconducting-cavity	959
	P. Sha, H. Huang Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China W.M. Pan, X.Y. Zhang IHEP, Beijing, People's Republic of China
	Spoke superconducting cavity can be used in the low-energy section of the proton accelerator. It has many significant advantages: compact structure, high value of R/Q, etc. The Chinese ADS (Accelerator Driven System) project will adopt many spoke cavities with 3 different β values (0.12, 0.21, 0.40). Spoke040 cavities (β=0.40) are used to increase the proton energy from 34 MeV to 178 MeV. Now the physical design of spoke040 cavity has been finished, and the machining are going on right now. The vertical test would be held at the end of this year.

THP052	Cornell’s Beam Line Higher Order Mode Absorbers	HOM, vacuum, cryomodule, damping	1027
	R.G. Eichhorn, J.V. Conway, Y. He, Y. Li, T.I. O'Connel, P. Quigley, J. Sears, N.R.A. Valles Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA V.D. Shemelin Cornell University, Ithaca, New York, USA
	Efficient damping of the higher-order modes (HOMs) of the superconducting cavities is essential for the proposed energy recovery linac at Cornell that aims for high beam currents and short bunches. Designing these HOM beamline absorbers has been a long endeavor, sometimes including disappointing results. We will review the design, the findings on the prototype and the final choices made for the 7 HOM absorbers being built for the main linac cryomodule (MLC) prototype.

THP056	Validation Procedures for the IFMIF Power Coupler Prototypes	operation, vacuum, controls, target	1043
	H. Jenhani, P. Carbonnier, Y. Gasser, N. Grouas, P. Hardy, V.M. Hennion, F. Orsini, Y. Penichot, B. Renard, D. Roudier CEA/IRFU, Gif-sur-Yvette, France S.J. Einarson, T.A. Treado CPI, Beverley, Massachusetts, USA D. Regidor, M. Weber CIEMAT, Madrid, Spain
	In the framework of the International Fusion Materials Irradiation Facility (IFMIF), which consists of two high power CW accelerator drivers, each delivering a 125 mA deuteron beam at 40 MeV, a Linear IFMIF Prototype Accelerator (LIPAc) is presently under design for the first phase of the project. The first two IFMIF Power Coupler Prototypes were manufactured for LIPAc. Series of acceptance tests have been performed successfully. Prototype Power Couplers have been then cleaned and assembled in an ISO 5 cleanroom. A dedicated test bench allowing RF conditioning of the couplers up to 200 kW CW at 175 MHz was achieved. RF power conditioning is planned to start during October 2013.

THP058	Update on the European XFEL RF Power Input Coupler	simulation, cryogenics, superconductivity, electron	1047
	D. Kostin, W.-D. Möller DESY, Hamburg, Germany W. Kaabi LAL, Orsay, France
	European XFEL project is being currently realized in Hamburg, Germany. The 1.5 km 17.5 GeV linear electron accelerator is based on the 1.3GHz 9-cell TESLA type SRF cavity. The RF power input coupler design for the E-XFEL is based on well known TTF3 coupler design, used in FLASH accelerator. Coupler design was adapted for the industrial production with some parameters optimisation revisited and simulations done. Results are presented and discussed.

THP060	High Power RF Coupler for ADS Accelerating Cavities	cavity, simulation, operation, Windows	1055
	S.V. Kutsaev, M.P. Kelly, B. Mustapha, J.A. Nolen, P.N. Ostroumov ANL, Argonne, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. Accelerator driven systems (ADS) require a high-power CW proton accelerator with proton beam energy near 1 GeV. High-gradient superconducting TEM-cavities are a natural choice for the front end of linac. This paper presents the design of superconducting low-beta half wave resonator operating at 162 MHz frequency for ADS, as well as a new 75 kW power coupler that has been designed at Argonne National Laboratory. This coupler would permit operations with an accelerating voltage of 3.0 MV with a beam current of 25 mA. The coupler includes a cold RF window which keeps the antenna at low temperature and a variable bellows section to adjust the coupling factor. The importance of these features for reliable operation will be discussed in detail.

THP064	HOM Couplers for CERN SPL Cavities	HOM, coupling, cavity, dipole	1066
	K. Papke, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany F. Gerigk CERN, Geneva, Switzerland
	Funding: Work supported by the Wolfgang-Gentner-Programme of the Bundesministerium für Bildung und Forschung (BMBF) Higher-Order-Modes (HOMs) may affect beam stability and refrigeration requirements of superconducting proton linacs such as the SPL, which is studied at CERN as the driver for future neutrino facilities. In order to limit beam-induced HOM effects CERN considers the use of HOM couplers on the cut-off tubes of the 5-cell superconducting cavities. These couplers consist of resonant antennas shaped as loops or probes which are designed to couple to modes of a specific frequency range. In this paper the design process is presented and a comparison is made between various design options for the medium and high-beta SPL cavities, both operating at 704 MHz. The RF characteristics, thermal behaviour and multipacting sensitivity of the various designs are discussed and 2 options are presented, which will be tested as warm prototypes on 5-cell high-beta copper cavity models.

THP066	SARAF Phase-I HWR Coupler Cooling Design	simulation, operation, cavity, proton	1073
	J. Rodnizki, Y. Ben Aliz, I. Fishman, A. Grin, Z. Horvitz, B. Kaizer, L. Weissman Soreq NRC, Yavne, Israel
	The Soreq Applied Research Accelerator Facility (SARAF) design is based on a 40 MeV 5 mA light ions superconducting RF linac. Phase I of SARAF delivers up to 2 mA CW proton beam in an energy range of 1.5-4.5 MeV. The maximum beam power that we have reached is 4.5 kW. The warming of the SARAF linac RF couplers is currently the main limiting factor for reaching higher CW beam power. The coupler cooling configuration was optimized by increasing the cold window copper braid and adding a copper braid to the top end, using CST Multiphysics and ANSYS steady state and transient solvers. The study was conducted for the heat load generated by the surface currents of a matched 4 kW forward CW power, simulated by the CST MWS FD solver. Multipacting is a known potential heat source that overheats the coupler in the vicinity of the cold window. The coupler overheat phenomena was experimentally studied as a function of DC bias voltage, and it was found that a 900 V bias reduces significantly the heating rate. As a result we expect that the beam power can be significantly increased. The long overheat period implies that optimization of the cooling configuration is still needed.

THP070	Analysis of High Order Modes in 1.3 GHz CW SRF Electron Linac for a Light Source	HOM, cavity, dipole, emittance	1085
	A.I. Sukhanov, A. Vostrikov, V.P. Yakovlev Fermilab, Batavia, USA
	Design of a Light Source (LS) based on the continuous wave superconducting RF (CW SRF) electron linac is currently underway. This facility will provide soft coherent X-ray radiation for a broad spectrum of basic research applications. Quality of the X-ray laser radiation is affected by the electron beam parameters such as the stability of the transverse beam position and longitudinal and transverse beam emittances. High order modes (HOMs) excited in the SRF structures by a passing beam may deteriorate the beam quality and affect the beam stability. Deposition of HOM energy in the walls of SRF cavities adds to the heat load of the cryogenic system and leads to the increased cost of building and operation of the linac. In this paper we evaluate effects of HOMs in an LS CW SRF linac based on Tesla-type 9-cell 1.3 GHz cavities. We analyze non-coherent losses and resonance excitation of HOMs. We estimate heat load due to the very high frequency HOMs. We study influence of the HOMs on the transverse beam dynamics.

THP071	HOM Studies of the Cornell ERL Main Linac Cavity in the Horizontal Test Cryomodule	HOM, cavity, cryomodule, experiment	1090
	N.R.A. Valles, R.G. Eichhorn, D.A. Goldman, G.H. Hoffstaetter, M. Liepe Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: Supported by NSF grant DMR-0807731 The Cornell energy recovery linac will accelerate a 100 mA beam to 5 GeV, while maintaining very low emittance (30 pm at 77 pC bunch charge). A major challenge to running such a large current continuously through the machine is the effect of strong higher-order modes (HOMs) in the SRF cavities that can lead to beam breakup. This paper presents the results of HOM studies for the prototype 7-cell cavity installed in a horizontal test cryomodule (HTC). HOM measurements were done for three HTC assembly stages, from initial measurements on the bare cavity to being fully outﬁtted with side-mounted RF input coupler and beam line HOM absorbers. We compare the simulated results of the optimized cavity geometry with measurements from all three HTC experiments, demonstrating excellent damping of all dipole higher order modes.

THP072	Input Coupler for Cornell ERL Main Linac	cavity, cryomodule, vacuum, operation	1094
	V. Veshcherevich, P. Quigley Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: Work is supported by the National Science Foundation grant DMR-0807731. Each cavity of the Cornell ERL Main Linac has a single coaxial type input coupler with fixed coupling, Qext = 6.5×E7. The input coupler will operate at RF power up to 5 kW at full reflection. The coupler design is based on the design of TTF-III input coupler with appropriate modifications and with taking into account the Cornell experience with couplers for ERL Injector. Seven couplers have been fabricated by CPI, Beverly and tested at Cornell on the test stand up to 5 kW CW. No major issues were noticed during the test. One coupler was attached to the prototype linac cavity. The cavity was successfully tested with great results achieved inside the horizontal test cryomodule. Six other couplers will be installed in the Main Linac Cryomodule (MLC) Prototype.

THP077	Coaxial Blade Tuner for European XFEL 3.9 GHz cavities	cavity, operation, simulation, cryomodule	1101
	R. Paparella, M. Bertucci, A. Bosotti INFN/LASA, Segrate (MI), Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy
	The European XFEL linac injector features a third harmonic section jointly realized by INFN and DESY and hosting a 3.9 GHz 9-cell cavities cryomodule. The cold tuning system, developed by INFN for these cavities, is inspired by the coaxial Blade Tuner already qualified for ILC cavities. Design, fabrication and room temperature qualification of first tuner units produced are reviewed in this paper.

THP078	Deformation Tuner Design for a Double Spoke Cavity	cavity, operation, cryomodule, SRF	1104
	N. Gandolfo, S. Bousson, S. Brault, P. Duchesne, P. Duthil, G. Olry, D. Reynet IPN, Orsay, France
	IPN Orsay is developing the low-beta double Spoke cavities cryomodule for the ESS. Based on previous successfully tested prototypes, a fast/slow tuner has been studied to compensate resonance frequency variations of the cavity during operation. The typical perturbations are coming from LHe pressure variations as well as microphonics and Lorentz force detuning (LFD). Two tuners are being built in order to validate both expected performances and series production feasibility. In this paper, the tuner design of the double Spoke cavity is presented.

THP079	Improvement of the Pneumatic Frequency Tuner of the Superconducting Resonators at IUAC	controls, cavity, vacuum, feedback	1107
	A. Pandey, G.K. Chaudhari, R.N. Dutt, S. Ghosh, D. Kanjilal, J. Karmakar, D.S. Mathuria, P. Patra, A. Rai, A. Roy, B.K. Sahu, S.K. Saini IUAC, New Delhi, India
	The existing phase locking scheme of the quarter wave resonators used in superconducting linear accelerator of Inter University Accelerator Centre consists of a fast (electronic) and a slow time scale (pneumatic) control. Presently, helium gas operated mechanical tuners are being used to phase lock the resonators against the master oscillator frequency and different ion beams have been accelerated and delivered to conduct experiments. The present pneumatic frequency tuner has two limitations: (a) no proportional flow control in vacuum condition (b) large hysteresis problem in the proportional valve responsible for gas flow control. Due to these limitations, the system becomes non-linear and the response time is very slow (~sec). Using the existing system, phase locking of a resonator becomes delicate and time consuming. In addition, it was found to be difficult to implement auto phase locking mechanism on the resonator. To overcome these problems and to improve the dynamics of the existing tuner, a new pneumatic tuning system has been adopted. Details of the existing tuning mechanism and the modified tuning system along with the test results will be presented in the paper.

FRIOB01	SRF Cavities for Future Ion Linacs	cavity, cryomodule, ion, SRF	1183
	Z.A. Conway, G.L. Cherry, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.H. Kim, S.V. Kutsaev, R.C. Murphy, B. Mustapha, P.N. Ostroumov, T. Reid ANL, Argonne, USA
	There is considerable interest worldwide in the applications of high-intensity (>5 mA) high-energy (>200 MeV) ion accelerators and the research which could be done with these machines. This presentation will present results of the three year ANL study funded specifically to make possible substantial reductions in the size and cost for future ion linacs in the region beta < 0.5. Applications include basic research, medical isotope production, and accelerator driven systems. High-performance low-beta resonators are key components of all of these machines. Recent 72.75 MHz, β = 0.077, quarter-wave resonator cold test results, designs and their impact on next generation ion accelerators are discussed. Peak fields in excess of 166 mT and 117 MV/m have been achieved and future work to improve upon this will be discussed.
	Slides FRIOB01 [3.833 MB]

FRIOB04	CERN Developments for 704 MHz Superconducting Cavities	cavity, niobium, operation, proton	1198
	O. Capatina, G. Arnau-Izquierdo, S. Atieh, I. Aviles Santillana, R. Bonomi, S. Calatroni, J.K. Chambrillon, R. Garoby, F. Gerigk, M. Guinchard, T. Junginger, M. Malabaila, L. Marques Antunes Ferreira, S. Mikulas, V. Parma, T. Renaglia, K.M. Schirm, T. Tardy, M. Therasse, A. Vacca, N. Valverde Alonso, A. Vande Craen CERN, Geneva, Switzerland F. Pillon Kraftanlagen Nukleartechnik GmbH, Heidelberg, Germany
	The Superconducting Proton Linac (SPL) is an R&D effort coordinated by CERN in partnership with other international laboratories. It is aiming at developing key technologies for the construction of a multi-megawatt proton linac based on state-of-the-art RF superconducting technology, which would serve as a driver in new physics facilities for neutrinos and/or Radioactive Ion Beam (RIB). Amongst the main objectives of this R&D effort, is the development of 704 MHz bulk niobium β=1 elliptical cavities, operating at 2 K with a maximum accelerating gradient of 25 MV/m, and the testing of a string of cavities integrated in a machine-type cryomodule. The cavity together with its helium tank had to be carefully designed in coherence with the innovative design of the cryomodule. New fabrication methods have also been explored. Five such niobium cavities and two copper cavities are in fabrication. The key design aspects are discussed, the results of the alternative fabrication methods presented and the status of the cavity manufacturing and surface preparation is detailed.
	Slides FRIOB04 [8.677 MB]

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MOIOA01

The FRIB Project at MSU

cavity, cryomodule, ion, operation

1

M. Leitner, B. Bird, F. Casagrande, S. Chouhan, C. Compton, J.L. Crisp, K. Elliott, A. Facco, A.D. Fox, M. Hodek, M.J. Johnson, G. Kiupel, I.M. Malloch, D. Miller, S.J. Miller, D. Morris, D. Norton, R. Oweiss, J.P. Ozelis, J. Popielarski, L. Popielarski, A.P. Rauch, R.J. Rose, K. Saito, M. Shuptar, N.R. Usher, G.J. Velianoff, D.R. Victory, J. Wei, J. Whitaker, K. Witgen, T. Xu, Y. Xu, O. Yair, S. Zhao
FRIB, East Lansing, USA

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The Facility for Rare Isotope Beams (FRIB) is ready to start construction. The facility will utilize a high-intensity, heavy-ion driver linac to provide stable ion beams from protons to uranium up to energies of >200 MeV/u and at a beam power of up to 400 kW. The superconducting cw linac consists of 330 individual low-beta (β = 0.041, 0.085, 0.29, and 0.53 at 80.5 MHz and 322 MHz) cavities in 49 cryomodules operating at 2 K. This paper discusses the current development status of the project with emphasis on the linac SRF acquisition. SRF coldmass and cryomodule component designs are briefly summarized. A SRF production facility, currently under construction, is described.

Slides MOIOA01 [9.804 MB]

MOIOA02

Status and Challenges of Spiral2 SRF Linac

cryomodule, cavity, vacuum, ion

11

R. Ferdinand, P.-E. Bernaudin, M. Di Giacomo
GANIL, Caen, France
P. Bosland
CEA/IRFU, Gif-sur-Yvette, France
Y. Gómez Martínez
LPSC, Grenoble Cedex, France
G. Olry
IPN, Orsay, France

GANIL is presently extending its experimental facility with the new SPIRAL2 project. It is based on a multi-beam Superconducting Linac Driver delivering 5 mA deuterons up to 40 MeV and 1 mA heavy ions up to 14.5 MeV/u. Several domains of research in nuclear physics at the limits of stability will be covered by this new accelerator. SPIRAL2 construction has two phases. SPIRAL2 phase 1 includes the superconducting accelerator driver, and the construction of the two research areas where the accelerated protons and deuterons will generate extremely intense neutron beams for fundamental physics experiments and numerous applications. SPIRAL2 will also accelerate stable heavy ion beams of very high intensity. The phase2 includes the RIB production building and links to the existing GANIL accelerator complex for RIB post acceleration. The Superconducting Linac incorporates many innovative developments of the Quarter-Wave resonators and their associated cryogenic and RF systems. The installation of the SPIRAL2 accelerator at GANIL has started. Status of the Spiral 2 SRF linac will be presented, focusing on the various SRF challenges met by this project and how/what solutions were chosen.
* on behalf of the SPIRAL2 project and superconducting teams

Slides MOIOA02 [87.841 MB]

MOIOA04

SRF Challenges for Energy Recovery Linacs

cavity, SRF, HOM, operation

24

A. Burrill
HZB, Berlin, Germany

Many of the challenges associated with operating a SRF ERL are independent of the choice of operating frequency, beam energy, and overall purpose of the machine. Worldwide there are an increasing number of ERLs in various stages of development and operation which are facing a number of similar challenges and often solving them in very different ways. In this talk I will seek to summarize the main challenges the community as a whole faces, address how different laboratories are working to solve these problems, and seek to identify areas of overlap where the community can work together to solve some of these common problems.

Slides MOIOA04 [5.213 MB]

MOIOA05

SRF in Heavy Ions Projects

cavity, ion, heavy-ion, cryomodule

30

D. Jeon
IBS, Daejeon, Republic of Korea

SRF technologies are widely applied to heavy ion accelerator projects in the world such as the RAON, C-ADS, HIAF, FRIB, SPIRAL2, ISAC-II, HIE-ISOLDE etc. In this talk, status report, design choices and SRF challenges met in heavy ion machines are presented.

Slides MOIOA05 [10.228 MB]

MOIOB01

High Power Proton/Deuteron Accelerators

SRF, proton, operation, cavity

35

J.-L. Biarrotte
IPN, Orsay, France

High power proton and deuteron linear accelerators can give rise to a large variety of scientific applications, useful for both fundamental and applied research. Thanks to the on-going efficient development of the superconducting RF technology, more and more projects based on such machines have emerged during the last 2 decades. This paper will review these existing high power proton/deuteron accelerator facilities or projects, trying in particular to emphasize in each case the various specificities and challenges related to the SRF technology.

Slides MOIOB01 [4.474 MB]

MOP002

Conceptual Design for Replacement of the DTL and CCL with Superconducting RF Cavities in the Spallation Neutron Source Linac

cryomodule, DTL, cavity, klystron

69

M.S. Champion, M. Doleans, S.-H. Kim
ORNL, Oak Ridge, Tennessee, USA

Funding: ORNL is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
The Spallation Neutron Source Linac utilizes normal conducting RF cavities in the low energy section from 2.5 MeV to 186 MeV. Six Drift Tube Linac (DTL) structures accelerate the beam to 87 MeV, and four Coupled Cavity Linac (CCL) structures provide further acceleration to 186 MeV. The remainder of the Linac is comprised of 81 superconducting cavities packaged in 23 cryomodules to provide a final beam energy of approximately 1 GeV. The superconducting Linac has proven to be substantially more reliable than the normal conducting Linac despite the greater number of stations and the complexity associated with the cryogenic plant and distribution. A conceptual design has been initiated on a replacement of the DTL and CCL with superconducting RF cavities. The motivation, constraints, and conceptual design are presented.

MOP003

Implications of Increased Beam Current for the Diamond Storage Ring RF System

cavity, storage-ring, operation, cathode

73

C. Christou, A. Bogusz, P. Gu, M. Maddock, P.J. Marten, S.A. Pande, A.F. Rankin, D. Spink, A.V. Watkins
Diamond, Oxfordshire, United Kingdom

Diamond Light Source presently operates for users with 300mA beam current and initial tests have begun to upgrade this current towards an ultimate goal of 500mA. The implications of such a beam current increase for the storage ring RF system will be significant, including the installation of a third superconducting cavity and a possible modification of the coupling parameters of the existing cavities. An overview of the planned enhancements of the RF system is presented, including an update of the procurement of a new CESR-design cavity and options for installation and operation of this cavity and supporting infrastructure.

MOP004

The ESS Superconducting Linear Accelerator

cryomodule, cavity, SRF, lattice

77

C. Darve, M. Eshraqi, M. Lindroos, D.P. McGinnis, S. Molloy
ESS, Lund, Sweden
P. Bosland
CEA/IRFU, Gif-sur-Yvette, France
S. Bousson
IPN, Orsay, France

The European Spallation Source (ESS) is one of Europe's largest planned research infrastructure. The collaborative project is funded by a collaboration of 17 European countries and is under design and construction in Lund, Sweden. The ESS will bring new insights to the grand challenges of science and innovation in fields as diverse as material and life sciences, energy, environmental technology, cultural heritage solid-state and fundamental physics. A 5 MW, long pulse proton accelerator is used to reach this goal. The pulsed length is 2.86 ms, the repetition frequency is 14 Hz (4 % duty cycle). The choice of SRF technology is a key element in the development of the ESS linear accelerator(linac). The superconducting linac is composed of one section of spoke cavity cryomodule (352 MHz) and two sections of elliptical cavity cryomodules (704 MHz). These cryomodules contain Niobium SRF cavities operating at 2 K. This paper presents the superconducting linac layout and its lifecycle.

MOP006

Status of the SC CW-Linac Demonstrator

cavity, solenoid, status, emittance

80

V. Gettmann, W.A. Barth, S. Jacke, S. Mickat, S. Mickat, A. Orzhekhovskaya
GSI, Darmstadt, Germany
M. Amberg, K. Aulenbacher, W.A. Barth, S. Jacke, S. Mickat
HIM, Mainz, Germany
M. Amberg, F.D. Dziuba, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany
K. Aulenbacher
IKP, Mainz, Germany

The commissioning of the superconducting (sc) continuous wave (cw) LINAC Demonstrator, financed by the Helmholtz Institute Mainz (HIM) mainly, is planned in 2014. The aim is a “full performance test” at GSI-High Charge Injector (HLI) of a 217 MHz sc CH-Cavity, which is designed by the Institute of Applied Physics (IAP) of the University Frankfurt. Inside the cryostat a suspended frame supports the cavity embedded by two solenoids. All of these components are in fabrication. The testing environment is about to be completed. The radiation protection bunker, and the beam transport line straightforward to the GSI-HLI, comprising beam diagnostic components as well as focusing and steering magnets, has been mounted.

MOP007

The Status of Superconducting Linac and SRF Activities at the SNS

cryomodule, cavity, operation, SRF

83

S.-H. Kim, W. Blokland, M.S. Champion, A. Coleman, M.T. Crofford, M. Doleans, D.L. Douglas, T.V. Gorlov, M.P. Howell, Y.W. Kang, A.P. Shishlo, S.E. Stewart, W.H. Strong
ORNL, Oak Ridge, Tennessee, USA
R. Afanador, B. DeGraff, B.S. Hannah, S.W. Lee, C.J. McMahan, T.S. Neustadt, S.W. Ottaway, C.C. Peters, J. Saunders, D.M. Vandygriff
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE.
There have been substantial gains at the Spallation Neutron Source (SNS) in last 7 years in understanding pulsed superconducting linac (SCL) operation including system and equipment limiting factors and resolution of system and equipment issues. Significant effort and focus are required to assure ongoing success of the operation, maintenance and improvement of the SCL, and to address the requirements of the upgrade project in the future. The SNS is taking a multi-faceted approach to maintaining and improving its linac. A balanced set of facilities which support processing, assembly, repair, and testing of cavities/cryomodules are currently being placed into service. This paper summarizes the status of the SNS SCL and related superconducting radio-frequency (SRF) activities such as development of ASME code-stamped spare cryomodules, R&D activities for SRF cavity performance improvements, SRF cavity development for power upgrade project and SRF facility development/upgrade to support all required activities.

MOP008

SUPERCONDUCTING LINAC FOR THE RISP

cavity, cryomodule, proton, ion

89

H.J. Kim, H.J. Cha, M.O. Hyun, H.J. Jang, D. Jeon, J.D. Joo, M.J. Joung, H.C. Jung, Y. Jung, Y. Kim, M. Lee, G.-T. Park
IBS, Daejeon, Republic of Korea

The RISP (Rare Isotope Science Project) accelerator has been planned to study heavy ion of nuclear, material and medical science at the Institute for Basic Science (IBS). It can deliver ions from proton to Uranium. The facility consists of three superconducting linacs of which superconducting cavities are independently phased. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the RISP linac design, the superconducting cavity, and cryomodule.

MOP010

Spiral2 Cryomodules B Tests Results

cryomodule, cavity, operation, alignment

95

G. Olry, F. Chatelet, C. Commeaux, N. Gandolfo, D. Grolet, C. Joly, J. Lesrel, D. Longuevergne, R. Martret, G. Michel, L. Renard, A. Stephen, P. Szott
IPN, Orsay, France
P.-E. Bernaudin, R. Beunard, R. Ferdinand, A. Lefevre
GANIL, Caen, France
Y. Gómez Martínez
LPSC, Grenoble Cedex, France

Assembly and tests of the SPIRAL2 superconducting linac's cryomodules at CEA/Saclay and IPN/Orsay have now reached cruising speed after having faced a series of problems, among them contamination. 19 cryomodules are composing the whole Linac and IPN Orsay is in charge of the 7 cryomodules B, housing two 88MHz, beta 0.12 Quarter-Wave Resonators. Two cryomodules have been successfully assembled and tested up to the nominal gradient of 6.5 MV/m for all cavities with also total cryogenic losses under specifications. One of them is fully qualified and has been already delivered to GANIL. The second one showed misalignment on one cavity which could lead to partial disassembly. This paper will present the results of those cryomodules tests as well as the status of the remaining ones.

MOP011

European XFEL 3.9 GHz System

cavity, HOM, cryomodule, controls

100

P. Pierini, M. Bertucci, A. Bosotti, C. Maiano, P. Michelato, L. Monaco, R. Paparella, D. Sertore
INFN/LASA, Segrate (MI), Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy
E. Vogel
DESY, Hamburg, Germany

The third harmonic system of the European XFEL is a joint INFN and DESY contribution to the project. Achievements, status and activity plan will be reviewed.

MOP012

Completion of the Superconducting Heavy Ion Linac at Inter-University Accelerator Centre

operation, electronics, ion, controls

103

A. Rai, R. Ahuja, J. Antony, S. Babu, J. Chacko, G.K. Chaudhari, A. Chaudhary, T.S. Datta, R.N. Dutt, S. Ghosh, R. Joshi, D. Kanjilal, S. Kar, J. Karmakar, M. Kumar, R. Kumar, D.S. Mathuria, R. Mehta, K.K. Mistri, A. Pandey, P. Patra, P.N. Prakash, A. Roy, J. Sacharias, B.K. Sahu, A. Sarkar, S.S.K. Sonti, S. K. Suman, J. Zacharias
IUAC, New Delhi, India

The Superconducting heavy ion Linac at Inter University Accelerator Centre (IUAC), New Delhi has been delivering accelerated ion beams to the users since 2009 *. Initially the first accelerating module, housing eight Quarter Wave Resonators (QWR’s), became operational together with the Superbuncher having one and the Rebuncher having two QWR’s, respectively. In the subsequent years, the remaining two modules have been installed and commissioned. The complete Linac was operated recently and several ion beams were delivered for scheduled experiments. The maximum energy gain was 8 MeV per charge state. Operational highlights include successful operation of four resonators in the third module with Piezo based ** mechanical tuning, implementation of remote phase locking for all resonators in three modules, development of a scheme for auto locking of resonators and testing of a capacitive pickup as a beam diagnostic element. Details will be presented vis-à-vis the problems encountered and the future course of action.
* A. Rai et. al., Proc. of SRF2009 Sept. 20–25, 2009, Berlin, Germany, page 244.
** B.K.Sahu et. al., Proc. of IPAC 2010, Kyoto Japan, page 2920.

MOP015

Status of the SRF Development for the Project X

cavity, cryomodule, SRF, proton

117

V.P. Yakovlev, T.T. Arkan, M.H. Awida, P. Berrutti, E. Borissov, A.C. Crawford, M.H. Foley, C.M. Ginsburg, I.V. Gonin, A. Grassellino, C.J. Grimm, S.D. Holmes, S. Kazakov, R.D. Kephart, T.N. Khabiboulline, V.A. Lebedev, A. Lunin, M. Merio, S. Nagaitsev, T.H. Nicol, Y.O. Orlov, D. Passarelli, T.J. Peterson, Y.M. Pischalnikov, O.V. Pronitchev, L. Ristori, A.M. Rowe, D.A. Sergatskov, N. Solyak, A.I. Sukhanov, I. Terechkine
Fermilab, Batavia, USA

Project X is a high intensity proton facility being developed to support a world-leading program of Intensity Frontier physics over the next two decades at Fermilab. The proposed facility is based on the SRF technology and consists of two linacs: CW linac to accelerate beam from 2.1 MeV to 3 GeV and pulsed linac accelerate 5% of the beam up to 8 GeV. In a CW linac five families of SC cavities are used: half-wave resonators (162.5 MHz); single-spoke cavities: SSR1 and SSR2 (325 MHz) and elliptical 5-cell β=0.6 and β=0.9 cavities (650 MHz). Pulsed 3-8 GeV linac linac are based on 9-cell 1.3 GHz cavities. In the paper the basic requirements and the status of development of SC accelerating cavities, auxiliaries (couplers, tuners, etc.) and cryomodules are presented as well as technology challenges caused by their specifics.

MOP017

SRF for Low Energy RHIC Electron Cooling: Preliminary Considerations

SRF, gun, electron, cavity

126

S.A. Belomestnykh, I. Ben-Zvi, M. Blaskiewicz, A.V. Fedotov, D. Kayran, V. Litvinenko, Q. Wu, B. P. Xiao, W. Xu, A. Zaltsman
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh, I. Ben-Zvi, V. Litvinenko
Stony Brook University, Stony Brook, USA
Z.A. Conway, M.P. Kelly, S.V. Kutsaev, B. Mustapha, P.N. Ostroumov
ANL, Argonne, USA

Funding: Work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE
A search for the QCD Critical Point has renewed interest to electron cooling ion beams in RHIC at energies below 10 GeV/nucleon. The electron cooling will utilize bunched electron beams form an SRF linac at energies from 0.9 to 5 MeV. The SRF linac will consist of two quarter wave structures: a photoemission electron gun and a booster cavity. In this paper we present preliminary design consideration of this SRF linac.

MOP018

Design of the MYRRHA 17-600 MeV Superconducting Linac

cavity, lattice, operation, simulation

129

J.-L. Biarrotte
IPN, Orsay, France
F. Bouly
CERN, Geneva, Switzerland
J.-P. Carneiro
Fermilab, Batavia, USA
D. Uriot
CEA/DSM/IRFU, France
D. Vandeplassche
SCK•CEN, Mol, Belgium

Funding: This work is being supported by the European Atomic Energy Community’s (EURATOM) Seventh Framework Programme under grant agreement n°269565 (MAX project).
The goal of the MYRRHA project is to demonstrate the technical feasibility of transmutation in a 100MWth Accelerator Driven System (ADS) by building a new flexible irradiation complex in Mol (Belgium). The MYRRHA facility requires a 600 MeV accelerator delivering a maximum proton flux of 4 mA in continuous operation, with an additional requirement for exceptional reliability. This paper will briefly describe the beam dynamics design of the main superconducting linac section which covers the 17 to 600 MeV energy range and requires enhanced fault-tolerance capabilities.

MOP021

Conceptual Design of SC Linac for RIBF-Upgrade Plan

cryomodule, cavity, quadrupole, ion

137

K. Yamada, O. Kamigaito, N. Sakamoto, K. Suda
RIKEN Nishina Center, Wako, Japan

For the intensity upgrade of very-heavy ions such as 238U and 124Xe at the RIKEN RI-Beam Factory (RIBF), a design study of new SC linac injector has started on. In the RIBF, the very-heavy ions are accelerated in a cascade of the injector linac (RILAC2), the RIKEN ring cyclotron (RRC), the fixed-frequency ring cyclotron (fRC), the intermediate-stage ring cyclotron (IRC), and the world's first superconducting ring cyclotron (SRC). We plan to substitute the SC linac for the RRC with respect to the very heavy ions, and to boost up the energy of ions with mass-to-charge ratio of 7 from 1.4 MeV/u to 11 MeV/u in the cw mode. The SC cavity is assumed to be a two gap QWR with an rf frequency of 73 MHz, that is twice the rf frequency of IRC and SRC. The cell parameters and number of cavity are determined by calculating the energy gain of synchronous ion by taking the rf phase at the center of gap into account. The transverse motion is calculated by the transfer matrix method and several types of lattice are studied. This contribution reports the progress of design study for the SC linac.

MOP029

Cryo-Losses Measurements of the XFEL Prototype and Pre-Series Cryomodules

cryomodule, operation, cryogenics, electron

162

S. Barbanotti, J. Eschke, K. Jensch, W. Maschmann, O. Sawlanski
DESY, Hamburg, Germany
W. Gaj, L.M. Kolwicz-Chodak, W. Maciocha
IFJ-PAN, Kraków, Poland
X. Wang
ESS, Lund, Sweden

Cryo-losses measurements of the XFEL prototype and pre-series cryomodules are here presented and compared with the XFEL requirements. Cryo-losses at the 4.5 K, 80 K and 2K temperatures are calculated during the test period at CMTB (CryoModule Test Bench) at DESY to qualify the cryomodules before installation. This paper summarizes the test procedure for the different circuits (2K, 4.5K, 80K) and in different load conditions: static losses, losses due to the magnet and dynamic losses due to the RF power sent to the cavities at different MV/m levels.

MOP033

Quality Assurance and Acceptance Testing of Niobium Material for Use in the Construction of the Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU)

niobium, cavity, SRF, controls

174

C. Compton, D. Miller
FRIB, East Lansing, USA
T.R. Bieler, D. Kang
Michigan State University, East Lansing, USA
S.K. Chandrasekaran, N.T. Wright
MSU, East Lansing, USA

Funding: Work supported by US DOE Cooperative Agreement DE-SC0000661 and Michigan State University
Niobium is the current material of choice for the fabrication of superconducting radio frequency (SRF) cavities used in SRF based accelerators. Although niobium specifications for this application have been well established, material properties of as-received materials can still vary substantially. As required for the FRIB accelerator, large volumes (60,000 lbs) of niobium materials (sheet, tube, and flange) have been contracted to several niobium vendors. The FRIB cavity designs require very large niobium sheets, increasing the difficulty in fabrication and potential for contamination. FRIB has developed and initiated plans to control niobium specifications and perform incoming acceptance checks to ensure quality is maintained. Acceptance results from the first niobium shipment will be presented, looking at several production lots from the same vendor and across multiple vendors. Non-conforming results were observed and will be discussed including follow-up investigations and mitigation strategies to improve quality of future shipments.

MOP039

Strategy of Technology Transfer of EXFEL Preparation Technology to Industry

cavity, controls, status, hardware

197

A. Matheisen, J. Iversen, A. Schmidt, W. Singer
DESY, Hamburg, Germany
P. Michelato, L. Monaco
INFN/LASA, Segrate (MI), Italy

For the EXFEL a specification for the cavitiy preparation procedures (R1)was set up and handed to the industrial companies. Basing on this specification companies hard ware as well as process flows were set up. Beside this specified part of the preparation technique the companies personal needed to be educated and the processes ramped up. To check the quality of the infrastructure, status of education of personal and correct set up of process flows, so called Dummy (DCV) - , Reference (RCV ) and Pre-series (PCV) cavities were assigned. We report on the general strategy applied for the EXFEL technology transfer on cavity preparation and the results obtained on the qualification cavities.
R1) Series Surface and acceptance test preparation of superconducting cavities for the European Xfel (XFEL/A - D) JUNE 30, 2009

MOP048

PED Requirements Applied to the Cavity and Helium Tank Manufacturing

cavity, niobium, controls, operation

227

A. Schmidt, J. Iversen, A. Matheisen, W. Singer
DESY, Hamburg, Germany

For the European XFEL more than 800 Cavities are manufactured by industrial partners. Each cavity is housed in an individual cryo vessel, the so called helium tank. All vessels are made from titanium and manufactured by industry as well. The cavity, welded into its helium tank, is a pressure loaded part and has to follow the pressure equipment directive - PED (97/23/EC). Setting up a series production of cavities and helium tanks by different vendors according given standards, was the task of the EXFEL WPG-1 LINAC-WP04. In cooperation with the TUEV-Nord as the notified body, DESY is responsible for the qualification of design, material in use and reasonable tests to get a certificate for pressure bearing parts.

MOP055

Status of the Superconducting Cavity Development for ILC

cavity, cryomodule, status, HOM

247

T. Yanagisawa, H. Hara, F. Inoue, K. Kanaoka, K. Sennyu
MHI, Hiroshima, Japan

MHI activities for ILC are reported. MHI had developed several procedure and method of cavity production for stable quality and cost reduction. And we are producing cryomodules too. These activities are reported in detail.

MOP057

Developments and Tests of a 700 MHz Cryomodule for the Superconducting Linac of MYRRHA

cavity, cryomodule, vacuum, cryogenics

250

F. Bouly
CERN, Geneva, Switzerland
S. Berthelot, J.-L. Biarrotte, M. El Yakoubi, C. Joly, J. Lesrel, E. Rampnoux
IPN, Orsay, France
A. Bosotti, R. Paparella, P. Pierini
INFN/LASA, Segrate (MI), Italy

Funding: This work is being supported by the European Atomic Energy Community’s EURATOM) Seventh Framework Programme under grant agreement n°269565(MAX project).
The MYRRHA (“Multi-purpose Hybrid Research reactor for High-tech Applications”) project aims at the construction of a new flexible fast spectrum research reactor. This reactor will operate as an Accelerator Driven System demonstrator. The criticality will be sustained by an external spallation neutron flux; produced thanks to a 600 MeV high intensity proton beam. This CW beam will be delivered by a superconducting linac which must fulfil very stringent reliability requirements. In this purpose, the accelerator design is based on a redundant and fault-tolerant scheme to enable the rapid mitigation of RF failures. To carry out “real scale” reliability-oriented experiments a prototype of cryomodule was developed by INFN Milano and installed at IPN Orsay. The module holds a 700 MHz 5-cell elliptical cavity (βg = 0.47) equipped with its blade frequency tuner. Several tests were carried out to commission the experimental set-up. We review here the obtained results and the lessons learnt by operating this module, as well as the on-going developments.

MOP065

Consolidated Design of the 17 MeV Injector for MYRRHA

cavity, proton, rfq, cryomodule

274

D. Mäder, D. Koser, H. Podlech, A. Schempp
IAP, Frankfurt am Main, Germany

Funding: Project supported by the EU, FP7 MAX, contract No. 269565 and BMBF, contract No. 06FY7102.
The MYRRHA research reactor will be an Accelerator Driven System, which demands a 2.4 MW proton beam delivered by a 600 MeV cw operated linac. The beam dynamics design of the injector has been consolidated to fulfil the requirements with respect to beam losses and quality. After a 4-rod-RFQ, four 7-gap room temperature CH cavities with a constant phase and an effective voltage of 750 keV are used to reach 4.3 MeV. Then the proton beam is accelerated to 18 MeV using six superconducting 5-gap Nb CH structures with a constant beta profile. With reducing the gradient and adjusting the phase of the twelfth CH structure the originally demanded 17 MeV can be delivered, too. Every SC CH cavity is cooled down to 2K with liquid helium in a separate cryo module. The new geometric design of the SC CH cavities improves the rigidity and reduces the electric peak field.

MOP066

Development of Compact Cryomodules Housing HWRs for High-intensity SC CW Linacs

cavity, cryomodule, niobium, proton

277

P.N. Ostroumov, Z.A. Conway, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.H. Kim, S.V. Kutsaev, R.C. Murphy, B. Mustapha, T. Reid
ANL, Argonne, USA
D. Berkovits
Soreq NRC, Yavne, Israel
S. Nagaitsev
Fermilab, Batavia, USA

Funding: This work was supported by the U.S. Department of Energy, under Contracts No. DE-AC02-06CH11357, DE-AC02-76CH03000 and ANL WFO No. 85Y47.
Acceleration of high-intensity light-ion beams immediately after an RFQ requires a compact accelerating and focusing lattice with a high packing factor. We have developed a cryomodule which satisfies this requirement with eight accelerating-focusing periods for Project X at FNAL. Each focusing period consist of a 162.5-MHz SC HWR, a SC solenoid and a beam position monitor. The highly optimized EM parameters of the cavity were achieved by using double conical, hour glass like, inner and outer conductors. This design is also favorable for the beam dynamics because the short focusing periods which helps to better control the beam quality. All sub-systems of the cryomodule, except the vacuum-vessel, are in advanced stages of prototyping and testing. A similar concept has been developed for the design of several cryomodules for a 20 MeV/u proton/deuteron 200 kW linac at SNRC. These cryomodules house two types of 176 MHz half-wave resonators and require only modest modifications for the application. This paper will discuss the status of the FNAL cryomodule design and sub-system fabrication and its impact on future HWR cryomodule such as the SNRC project.

MOP067

Results From Initial Tests of the 1st Production Prototype β=0.29 and β=0.53 HWR Cavities for FRIB

cavity, target, cryomodule, vacuum

280

J.P. Ozelis, C. Compton, K. Elliott, M. Hodek, M. Leitner, I.M. Malloch, D. Miller, S.J. Miller, D. Norton, R. Oweiss, J. Popielarski, L. Popielarski, A.P. Rauch, K. Saito, G.J. Velianoff, D.R. Victory
FRIB, East Lansing, USA

Funding: Work supported by US DOE Cooperative Agreement DE-SC0000661 and Michigan State University
The first prototypes of the β=0.53 and β=0.29 HWR production design cavities for FRIB were fabricated early this year by Roark Manufacturing Company and delivered to MSU. These cavities have undergone an extensive evaluation program to verify both mechanical and RF performance before proceeding with fabrication of a pre-production run of 10 cavities. Results from physical inspections, warm RF measurements, chemical processing, and cryogenic vertical testing will be presented.

MOP068

NGLS Linac Design

cryomodule, cavity, cryogenics, controls

286

R.P. Wells, J.M. Byrd, J.N. Corlett, L.R. Doolittle, P. Emma, A. Ratti
LBNL, Berkeley, California, USA
C. Adolphsen, C.D. Nantista
SLAC, Menlo Park, California, USA
D. Arenius
JLAB, Newport News, Virginia, USA
C.M. Ginsburg, T.J. Peterson
Fermilab, Batavia, USA

Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
The Next Generation Light Source (NGLS) is a design concept for a multibeamline soft x-ray FEL array powered by a CW superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. This paper describes the concepts for the cavity and cryostat design operating at 1.3 GHZ and based on minimal modifications to the design of ILC cryomodules, This leverages the extensive experience derived from R&D that resulted in the ILC design. Due to the different nature of the two applications, particular attention is given now to high loaded Q operation and microphonics control, as well as high reliability and expected up time. The work describes the design and configuration of the linac, including choice of gradient, possible modes of operation, cavity design and RF power, as well as the consequent requirements for the cryogenic system.

MOP069

Precise Measurement of Superconducting Cavity Movement in Cryomodule by the Position Monitor Using White Light Interferometer

target, cryomodule, cavity, superconducting-cavity

291

H. Sakai, T. Aoto, K. Enami, T. Furuya, M. Sato, K. Shinoe, K. Umemori
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
K. Hayashi, K. Kanzaki
Tokyo Seimitsu Co. Ltd, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

Alignment of Superconducting cavity is one of the important issues for linear collider and/or future light source like ERL and X-FEL. To measure the cavity displacement under cooling to Liq He temperature more precisely, we newly developed the position monitor by using white light interferometer. This monitor is based on the measurement of the interference of light between the measurement target and the reference point. It can measure the position from the outside of the cryomodule. We applied this monitor to the main linac cryomodule of Compact ERL and successfully measured the displacement during 2K cooling with the resolution of 10 micron

MOP071

Record Quality Factor Performance of the Prototype Cornell ERL Main Linac Cavity in the Horizontal Test Cryomodule

cavity, cryomodule, experiment, higher-order-mode

300

N.R.A. Valles, R.G. Eichhorn, F. Furuta, G.M. Ge, D. Gonnella, D.L. Hall, Y. He, K.M.V. Ho, G.H. Hoffstaetter, M. Liepe, T.I. O'Connel, S. Posen, P. Quigley, J. Sears, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: Supported by NSF grant DMR-0807731
Future SRF linac driven accelerators operated in CW mode will require very efficient SRF cavities with high intrinsic quality factors Q at medium accelerating fields. Cornell has recently ﬁnished testing the fully equipped 1.3 GHz, 7-cell main linac cavity for the Cornell Energy Recovery Linac in a horizontal test cryomodule (HTC). Measurements characterizing the fundamental mode’s quality factor have been completed, showing record Q performance. In this paper, we present detailed quality factor vs gradient results for three HTC assembly stages. We show that the performance of an SRF cavity can be maintained when installed into a cryomodule, and that thermal cycling reduces residual surface resistance. We present world record results for a fully equipped multicell cavity in a cryomodule, reaching intrinsic quality factors at operating accelerating field of Q(E =16.2 MV/m, 1.8K) > 6·10¹⁰ and Q(E =16.2 MV/m, 1.6K) > 1.0·10¹¹, corresponding to a very low residual surface resistance of 1.1 nOhm.

MOP074

Design and Construction of the Main Linac Cryomodule for the Energy Recovery Linac Project at Cornell

cryomodule, vacuum, alignment, cryogenics

308

R.G. Eichhorn, B. Bullock, J.V. Conway, Y. He, T.I. O'Connel, P. Quigley, D.M. Sabol, J. Sears, E.N. Smith, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Cornell University has been designing and building superconducting accelerators for various applications for more than 50 years. Currently, an energy-recovery linac (ERL) based synchrotron-light facility is proposed making use of the existing CESR facility. As part of the phase 1 R&D program funded by the NSF, critical challenges in the design were addressed, one of them being a full linac cryo-module. It houses 6 superconducting cavities- operated at 1.8 K in continuous wave (CW) mode - with individual HOM absorbers and one magnet/ BPM section. Pushing the limits, a high quality factor of the cavities and high beam currents (2*100 mA)are targeted. We will present the design of the main linac module (MLC) being finalized recently, its cryogenic features and report on the status of the fabrication which started in late 2012

MOP081

Preliminary Studies of the Cryogenic Refrigerator and Distribution Systems for the MYRRHA Proton Linac

cryogenics, cryomodule, proton, operation

331

T. Junquera, N.R. Chevalier, J.P. Thermeau
Accelerators and Cryogenic Systems, Orsay, France
L. Medeiros Romão, D. Vandeplassche
SCK•CEN, Mol, Belgium
H. Saugnac
IPN, Orsay, France

Funding: Work supported by the EU, FP7 MAX contract number 269565
In the framework of recent European programs (FP6-Eurotrans, FP7-MAX), the SC proton Linac for the MYRRHA project (associating an accelerator to a subcritical nuclear reactor, to be installed in the SCK•CEN at Mol-Belgium), has been extensively studied and optimized to reach strict requirements in beam power and reliability as needed for this ADS demonstrator. The linac, composed of 150 SC cavities (CH, spoke and elliptical) installed in 60 cryomodules, operates at 2K, delivering a beam power of 2.5 MW (600 MeV, 4 mA) in CW mode, will be installed in a tunnel of 240 m length. In this paper we present the evaluation of the cryogenic power requirements, a preliminary architecture of the cryogenic refrigerator system including all its major components, and preliminary proposals for the cryofluids distribution along the SC linac.

MOP082

Development and Test of a New Cryostat Module for the Injector of the S-DALINAC*

electron, operation, vacuum, cavity

334

T. Kürzeder, J. Conrad, F. Hug, N. Pietralla, A. Richter, S.T. Sievers
TU Darmstadt, Darmstadt, Germany
R.G. Eichhorn
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: *This work is supported by the DFG through the Collaborative Research Center SFB 634.
The present injector of the superconducting Darmstadt electron linear accelerator S-DALINAC provides an electron beam of up to 10 MeV kinetic energy and up to 60 μA current in continuous wave operation. A new cryostat module has been constructed to replace the actual one in order to provide higher beam energies of up to 14 MeV and currents of up to 250 μA for nuclear resonance fluorescence experiments at the Darmstadt High Intensity Photon Setup (DHIPS). As before two 20-cell superconducting microwave cavities will be operated at an acceleration frequency of 3 GHz in a liquid helium bath at 2 K. For the injector upgrade two new elliptical 20-cell niobium cavities were also manufactured and in addition a third spare one. The rf power is transferred to the cavities by an also newly developed waveguide-transition line and input couplers. We report on the construction of the cryostat module and its components and present the results of a first cooling-down procedure.

MOP085

Status of the Superconducting Proton Linac (SPL) Cryomodule

cavity, vacuum, cryogenics, operation

345

V. Parma, R. Bonomi, O. Capatina, J.K. Chambrillon, E. Montesinos, K.M. Schirm, A. Vande Craen, G. Vandoni, R. van Weelderen
CERN, Geneva, Switzerland
G. Devanz
CEA/IRFU, Gif-sur-Yvette, France
P. Duchesne, P. Duthil, S. Rousselot
IPN, Orsay, France

The Superconducting Proton Linac (SPL) is an R&D effort conducted by CERN in partnership with other international laboratories, aimed at developing key technologies for the construction of a multi-megawatt proton linac based on state-of-the-art SRF technology. Such an accelerator would serve as a driver in new physics facilities for neutrinos and/or radioactive ion beams. Amongst the main objectives of this effort, are the development of 704 MHz bulk niobium β=1 elliptical cavities (operating at 2 K and providing an accelerating field of 25 MV/m) and the test of a string of cavities integrated in a machine-type cryo-module. In an initial phase, only four out of the eight cavities of the SPL cryo-module will be tested in a half- length cryo-module developed for this purpose, which nonetheless preserves the main features of the full size machine. This paper presents the final design of the cryo-module and the status of the construction of the main cryostat parts. Preliminary plans for the assembly and testing of the cryo-module at CERN are presented and discussed.

MOP086

Integration, Commissioning and Cryogenics Performance of the ERL Cryomodule Installed on ALICE-ERL Facility at STFC Daresbury Laboratory, UK

cryomodule, cryogenics, SRF, HOM

349

S.M. Pattalwar, R.K. Buckley, P.A. Corlett, P. Goudket, A.R. Goulden, A.J. May, P.A. McIntosh, A.E. Wheelhouse
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
S.A. Belomestnykh
BNL, Upton, Long Island, New York, USA
A. Büchner, F.G. Gabriel, P. Michel
HZDR, Dresden, Germany
E.P. Chojnacki, J.V. Conway, R.G. Eichhorn, G.H. Hoffstaetter, M. Liepe, H. Padamsee, P. Quigley, J. Sears, V.D. Shemelin
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
M.A. Cordwell, T.J. Jones, L. Ma, A.J. Moss, J. Strachan
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
J.N. Corlett, D. Li, S.M. Lidia
LBNL, Berkeley, California, USA
T. Kimura
Stanford University, Stanford, California, USA
R.E. Laxdal
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
J.K. Sekutowicz
DESY, Hamburg, Germany
T.J. Smith
SLAC, Menlo Park, California, USA

On successful assembly and preliminary testing of an optimised SRF cryomodule for application on ERL accelerators, which is being developed through an international collaboration the cryomodule has been installed on the 35 MeV ALICE (Accelerators and Lasers in Combined Experiments) Energy Recovery Linac (ERL) facility at STFC Daresbury Laboratory. Existing cryogenic infrastructure has a capacity to deliver approximately 120 W cooling power at 2 K, but the HOM (Higher Order Mode) absorbers, the thermal intercepts for the high power RF couplers and the radiation shield in the cryomodule are designed to be cooled (to 5 K and 80 K) with gaseous helium instead of liquid nitrogen. As a result the cryogenic infrastructure for ALICE had to be modified to meet these additional requirements. In this paper we describe our experience with the process of integration and the cryogenic commissioning, and present some initial results.

MOP090

Feasibility of Using Conductively Cooled Magnets in Cryomodules of Superconducting Linacs

radiation, cryomodule, focusing, solenoid

361

I. Terechkine, S. Cheban, T.H. Nicol, V. Poloubotko, D.A. Sergatskov
Fermilab, Batavia, USA

While trying to find an optimal way to configure cryomodule for the low energy part of a high-current, high-power superconducting linac, an option of using conductively cooled superconducting focusing lenses was evaluated. As part of this evaluation, several tests were made using existing test cryostat. The cryostat was modified by adding current feed-throughs and two conductively cooled current leads, each equipped with heat sinks at the temperatures of liquid nitrogen and liquid helium. A superconducting magnet was mounted inside the cryostat on an individual heat sink, and thermometers were installed on the leads, heat sinks, and on the magnet’s winding. In this report we provide some details of the heat exchangers’ designs, compare predicted and measured temperature distribution along the leads, and analyze results of the winding temperature measurements.

TUP026

Performance of a FNAL Nitrogen Treated Superconducting Niobium Cavity at Cornell

cavity, niobium, SRF, superconductivity

475

D. Gonnella, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
A. Grassellino
Fermilab, Batavia, USA

Funding: NSF
In many tests of superconducting cavities, the performance of the cavity in the medium field region will be limited by medium field Q slope. For projects such as the proposed Cornell Energy Recovery Linac, high Q operation at medium fields is necessary to meet specifications for efficient CW cavity operation. A single cell cavity was prepared by Fermilab by electropolishing it and baking it at 1000°C with 1x10^-2 Torr of Nitrogen, and subsequently tested at Cornell. The cavity displayed an increase in Q at medium fields between 5 and 20 MV/m at 2.0 K, opposite of the usual medium field Q slope. The material properties of this cavity were studied and correlated with performance. This analysis helps to better understand how to overcome medium field Q slope and improve cavity performance in future CW SRF machines such as the Cornell ERL.

TUP027

High Q0 Studies at Cornell

cavity, niobium, SRF, factory

478

D. Gonnella, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: NSF
The construction and preparation of superconducting RF cavities with very high quality factors is very advantageous for future particle accelerators operating in CW mode. Until recently, the highest quality factors measured in SRF cavities were on the order of 10¹¹. A Cornell ERL single-center-cell cavity was prepared with BCP and a five day heat treatment at 1000°C. Following this treatment, the cavity was tested and achieved a record high intrinsic quality factor of 2.9·10¹¹ at 1.4 K, corresponding to a very small residual resistance of (0.35±0.10) nOhm. This cavity was then given a series of BCP’s of 5, 75, and 200 μm and retested. Material properties were extracted from the data hinting at a very low mean free path of the niobium. In this paper we discuss the unusual material properties of the surface layer of the cavity and their implication for the RF performance of the cavity.

TUP044

Surface Processing Facilities for Spoke Cavities at IHEP

cavity, recirculation, superconductivity, LLRF

508

J.P. Dai, H. Li, L.H. Li, Q.Y. Wang, J. Zhang
IHEP, Beijing, People's Republic of China
P. Sha
Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China

Funding: Work supported by the "Strategic Priority Research Program" of CAS, under Grant No. XDA03020600
The China ADS injector I program is building a CW 10MeV Superconducting proton linac at IHEP. To develop the superconducting spoke-type cavities incorporated in this linac, a set of new surface processing facilities were built and successfully used to treat the Spoke012 prototype cavities. In this paper, we present the design, fabrication and operation of these facilities, including BCP, HPR and UPW, etc.

TUP057

Plasma Processing R&D for the SNS Superconducting Linac RF Cavities

plasma, cavity, cryomodule, niobium

551

M. Doleans, W. Blokland, M.T. Crofford, D.L. Douglas, M.P. Howell, S.-H. Kim, P.V. Tyagi
ORNL, Oak Ridge, Tennessee, USA
R. Afanador, J.A. Ball, B. DeGraff, B.S. Hannah, S.W. Lee, C.J. McMahan, J. Saunders
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: This work was supported by SNS through UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. DOE
The Spallation Neutron Source routinely operates with a proton beam power of 1 MW on its production target. A plan to reach the design 1.4 MW within a few years is in place* and relies on increasing the ion beam current, pulse length and beam energy in the linac. The increase in beam energy from the present 930 MeV to 1 GeV will require an increase of approximately 15% in the accelerating gradient of the superconducting linac high-beta cryomodules. In-situ plasma processing was identified as a promising technique** to reduce electron activity in the SNS superconducting cavities and increase their accelerating gradient. R&D on plasma processing aims at deploying the new in-situ technique in the linac tunnel by 2016. Overall plan and current status of the plasma processing R&D will be presented.
* NScD Five year plan 2012-2016, SNS-NSCD-EXE-PN-0001, R00, ORNL
** S-H Kim et al., “R&D Status for In-Situ Plasma Surface Cleaning of SRF Cavities at Spallation Neutron Source”, PAC 2011 Proceedings

TUP069

The Copper Substrate Developments for the HIE-ISOLDE High-Beta Quarter Wave Resonator

cavity, electron, cryogenics, operation

596

L. Alberty, G. Arnau-Izquierdo, I. Aviles Santillana, S. Calatroni, O. Capatina, A. D'Elia, G. Foffano, Y. Kadi, P. Moyret, K.M. Schirm, T. Tardy, W. Venturini Delsolaro
CERN, Geneva, Switzerland
A. D'Elia
UMAN, Manchester, United Kingdom

A new linac using superconducting quarter-wave resonators (QWR) is under construction at CERN in the framework of the HIE-ISOLDE project. The QWRs are made by Niobium sputtered on a bulk Copper substrate. The working frequency at 4.5 K is 101.28 MHz and they will provide 6 MV/m accelerating gradient on the beam axis with a total maximum power dissipation of 10 W. The properties of the cavity substrate have a direct impact on the final cavity performance. The Copper substrate has to ensure an optimum surface for the Niobium sputtered layer. It has also to fulfill the required geometrical tolerances, the mechanical stability during operation and the thermal performance to optimally extract the RF dissipated power on cavity walls. The paper presents the mechanical design of the high β cavities. The procurement process of the Copper raw material is detailed, including specifications and tests. The manufacture sequence of the complete cavity is then explained and the structural and thermo-mechanical behavior during the tests performed on a prototype cavity is discussed. The industrialization strategy is presented in view of final production of the cavities.

TUP085

Study of NbTi Welded Parts

niobium, cavity, laser, plasma

659

N. Bazin, C.Z. Antoine
CEA/DSM/IRFU, France
C. B. Baumier, G. Martinet
IPN, Orsay, France
F. F. Fortuna
CSNSM, ORSAY CAMPUS, France
J.-B. Sirven
Commisariat à l'Energie Atomique (CEA/DEN/DPC), Direction de l'Energie Nucléaire, Gif-sur-Yvette, France

Due to its properties, niobium-titanium alloy is widely used to manufacture the flanges of superconducting niobium accelerating cavities. The material hardness is compliant to provide UHV-tight connections with aluminum gaskets or spring-type gaskets (Helicoflex). And the alloy can be directly welded to the niobium. The paper will present the surface analysis made on NbTi samples after the chemical treatment and on a Nb / NbTi weld.

TUP087

RF Test Results of the first Nb3Sn Cavities Coated at Cornell

cavity, niobium, SRF, operation

666

S. Posen, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

As an alternative material to niobium for SRF cavities in particle accelerators, Nb3Sn presents two significant advantages. With a Tc of 18 K, it has a very small surface resistance at a given temperature, leading to a significant reduction in cryogenic costs; and with a predicted Hsh of nearly 400 mT, it has the potential to produce cavities with higher gradients and therefore shorter high energy linacs. Recently, two 1.3 GHz cavities have been fabricated and coated with Nb3Sn at Cornell. Tests of these first cavities have produced encouraging results, including a very high Tc and some very high-performing surface regions. These cavity results as well as new results of samples studied using TEM will be presented.

TUP091

Field Emission Measure During cERL Main Linac Cryomodule High Power Test in KEK

cavity, radiation, electron, cryomodule

678

E. Cenni
Sokendai, Ibaraki, Japan
K. Enami, T. Furuya, H. Sakai, M. Satoh, K. Shinoe, K. Umemori
KEK, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

A compact Energy Recovery Linac (cERL) is under construction in KEK in order to proof the performance of the key components required for the future ERL project in KEK. The main linac L-band cavities were assembled and tested in the cryomodule under high power operation, during the test information concerning field emission were gathered by means of PIN diodes rings and NaI scintillator located at the cavities ends. The data were analyzed by means of simulations, taking into account the cavities operating conditions and interaction between the accelerated electrons and the cavity surface. The resulting information are used to deduce a possible emitter location, determining if there is any change in the cavities performance with respect to the last vertical test they undertook. With PIN diode is possible to observe the radiation pattern produced by field emission, inferring the meridian where the emitter belongs. On the other hand the bremsstrahlung spectra recorded with the scintillator allow an estimation of the cavity cell where the emitter is located.

TUP116

Quench field and Location in Vertical Tests at KEK-STF

cavity, linear-collider, accelerating-gradient, cryomodule

751

Y. Yamamoto, E. Kako, T. Shishido
KEK, Ibaraki, Japan

Many vertical tests have been done for the ILC and ERL at KEK-STF since 2008. T-mapping system (fixed type) was equipped at every vertical test, and quench location was identified completely. Every quench location at quench field will be presented in this paper.

WEIOA03

Nb Sputtered Quarter Wave Resonators for the HIE-ISOLDE

cavity, cathode, niobium, vacuum

767

W. Venturini Delsolaro, S. Calatroni, A. D'Elia, B. Delaup, N.M. Jecklin, Y. Kadi, P. Maesen, I. Mondino, A. Sublet, M. Therasse
CERN, Geneva, Switzerland
A. D'Elia
UMAN, Manchester, United Kingdom
D.A. Franco Lespinasse, G. Keppel, V. Palmieri, S. Stark
INFN/LNL, Legnaro (PD), Italy

The HIE-ISOLDE superconducting linac will be based on quarter wave resonators (QWRs), made by Niobium sputtering on Copper. The operating frequency at 4.5 K is 101.28 MHz and the required performance for the high beta cavity is 6 MV/m accelerating field for 10 W maximum power dissipation. These challenging specifications were recently met at CERN at the end of a vigorous development program. The paper reports on the progress of the cavity RF performance with the evolution of the sputtering process; it equally illustrates the parallel R&D which is ongoing at CERN and at INFN in the quest for even higher performances.

Slides WEIOA03 [14.564 MB]

WEIOD01

Review of Magnetic Shielding Designs of Low-Beta Cryomodules

solenoid, cavity, cryomodule, shielding

800

R.E. Laxdal
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

It is well known that superconducting cavities can trap magnetic flux while cooling through transition. The trapped flux adds to the residual rf surface resistance. For this reason magnetic shielding is added to the cryomodules to shield the cavities from the environmental magnetic field. The low beta portion of many superconducting hadron linear accelerators, either in operation or in production, includes cryomodules containing one or more high field superconducting solenoids. The operation of a high field solenoid in close proximity to a cavity adds a level of complexity to the cryomodule design considerations. The paper will summarize the various techniques that can be employed to reduce the risk of magnetic pollution from internal solenoids.

Slides WEIOD01 [10.342 MB]

WEIOD02

Magnetic Shielding: Our Experience with Various Shielding Materials

shielding, cryogenics, superconducting-RF, simulation

808

M. Masuzawa, A. Terashima, K. Tsuchiya
KEK, Ibaraki, Japan
A. Daël, O. Napoly, J. Plouin
CEA/DSM/IRFU, France

Magnetic shielding is a key technology for superconducting RF cavities. The tolerance of the ambient magnetic field depends on factors such as the operating RF frequency and acceleration gradient, but it can be as small as a few mG. Some high-Ni-content alloys, such as Cryperm 10 or Cryophy, which are claimed to maintain high permeability at cryogenic temperatures where superconducting cavities are operated, are commercially available at present and are used for magnetic shielding of superconducting cavities at many laboratories. Permeability measurements were made in order to understand the characteristics of such materials at both room and cryogenic temperatures, and the results will be used as a database for designing magnetic shields. It was found that the catalog performance of such materials was not always reproduced in the measurements. Some degradation was observed which depended on how the material was handled. The results of investigation into possible causes for the performance degradation of the shielding material at cryogenic temperature will be presented, along with permeability measurement results for various materials at different temperatures.

Slides WEIOD02 [8.475 MB]

THIOA02

The Challenge to Assemble 100 Cryomodules for the European E-XFEL

cryomodule, cavity, controls, vacuum

816

C. Madec
CEA, Gif-sur-Yvette, France
S. Berry, J.-P. Charrier, M. Fontaine, Y. Gasser, O. Napoly, C.S. Simon, T.V. Vacher, B. Visentin
CEA/DSM/IRFU, France
P. Charon, C. Cloué, G. Monnereau, J.L. Perrin, D. Roudier, Y. Sauce, T. Trublet
CEA/IRFU, Gif-sur-Yvette, France

As In-Kind contributor to the E-XFEL project, CEA is committed to the integration on the Saclay site of the 100 cryomodules (CM) of the superconducting linac as well as to the procurement of miscellaneous parts including 31 cold beam position monitors (BPM) of the re-entrant type. The assembly infrastructure has been renovated from the previous Saturne Synchrotron Laboratory facility: it includes a 200 m2 clean room complex with 112 m2 under ISO4, 1325 m2 of assembly platforms and 400 m2 of storage area. In parallel, CEA has conducted industrial studies and three cryomodule assembly prototyping both aiming at preparing the industrial file, the quality management system and the commissioning of the assembly plant, tooling and control equipment. In 2012, the contract of the integration has been awarded to ALSYOM. The first pre-series modules have been assembled and are being tested at DESY. This paper will present the challenges of the module integration from the preparation phase to the industrial phase.

Slides THIOA02 [17.641 MB]

THIOA05

Optimization of SRF Linacs

cryomodule, cavity, cryogenics, operation

830

T. Powers
JLAB, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S.
This work describes preliminary results of a new software tool that allows one to vary parameters and understand the effects on the optimized costs of construction plus 10 year operations of an SRF linac, the associated cryogenic facility, and controls, where operations includes the cost of the electrical utilities but not the labor or other costs. It derives from collaborative work done with staff from Accelerator Science and Technology Centre, Daresbury, UK several years ago while they were in the process of developing a conceptual design for the New Light Source project. The initial goal was to convert a spread sheet format to a graphical interface to allow the ability to sweep different parameter sets. The tools also allow one to compare the cost of the different facets of the machine design and operations so as to better understand the tradeoffs. More recent additions to the software include the ability to save and restore input parameters as well as to adjust the Qo versus E parameters in order to explore the potential costs savings associated with doing so.

Slides THIOA05 [2.712 MB]

THIOB01

CEBAF Upgrade: Cryomodule Performance and Lessons Learned

cryomodule, cavity, vacuum, controls

836

M.A. Drury, J. Hogan, C. Hovater, L.K. King, H. Park, J.P. Preble, R.A. Rimmer, H. Wang, M. Wiseman
JLAB, Newport News, Virginia, USA
G.K. Davis, C.E. Reece
JLab, Newport News, Virginia, USA
F. Marhauser
Muons, Inc, Illinois, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract DE-AC05-06OR23177.
The Thomas Jefferson National Accelerator Facility is currently engaged in the 12 GeV Upgrade Project. The goal of the 12 GeV Upgrade is a doubling of the available beam energy of the Continuous Electron Beam Accelerator Facility (CEBAF) from 6 GeV to 12 GeV. The increase in beam energy will largely be due to the addition of ten C100 cryomodules and the associated RF in the CEBAF linacs. These cryomodules are designed to deliver 100 MeV per cryomodule. Each C100 cryomodule contains a string of eight seven-cell, electro-polished, superconducting RF cavities. While an average performance of 100 MV is needed to achieve the overall 12 GeV beam energy goal, the actual performance goal for the cryomodules is an average energy gain of 108 MV to provide operational headroom. All ten of the C100 cryomodules are installed in the linac tunnels and are on schedule to be commissioned by September 2013. Commissioned performance has ranged from 104 MV to 118 MV. In May, 2012, a test of an early C100 achieved 108 MV with full beam loading. This paper will discuss the performance of the C100 cryomodules along with operational challenges and lessons learned for future designs.
The U.S. Govt. retains a non-exclusive, paid-up,irrevocable,world-wide license to publish or reproduce this manuscript.

Slides THIOB01 [2.534 MB]

THIOB02

High Q Cavities for the Cornell ERL Main Linac

cavity, cryomodule, SRF, HOM

844

R.G. Eichhorn, B. Bullock, B. Clasby, B. Elmore, F. Furuta, A. Ganshin, G.M. Ge, D. Gonnella, D.L. Hall, Y. He, K.M.V. Ho, G.H. Hoffstaetter, J.J. Kaufman, M. Liepe, T.I. O'Connel, S. Posen, P. Quigley, J. Sears, V.D. Shemelin, E.N. Smith, V. Veshcherevich
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

While SRF research for linear colliders was focused on achieving high gradients, Cornell’s proposal for an energy recovery linac (ERL) demanded for low cw losses. Starting several years ago, a high-Q R&D phase was launched that led to remarkable results recently: A fully dressed cavity (7 cells, 1.3 GHz) with side-mounted input coupler and beamline HOM absorbers achieved a Q of 3.5·10¹⁰ ((16 MV/m, 1.8 K). This talk will review the staged approach we have chosen in testing a single cavity in a horizontal short cryomodule (HTC), report results on each step and conclude on our findings about preserving high Q from vertical testing. We also discuss the production of six additional cavities as we progress toward constructing a full 6-cavity cryomodule as a prototype for Cornell’s main linac module

Slides THIOB02 [8.378 MB]

THIOC01

Low Beta Cavity Development for an ATLAS Intensity Upgrade

cavity, cryomodule, niobium, ion

850

M.P. Kelly, Z.A. Conway, S.M. Gerbick, M. Kedzie, S.H. Kim, R.C. Murphy, B. Mustapha, P.N. Ostroumov, T. Reid
ANL, Argonne, USA

The set of seven new 72 MHz quarter wave SC (QWR) cavities has been completed and is being installed in the ATLAS heavy-ion accelerator at Argonne. The aim is to provide at least 17.5 MV accelerating potential with large acceptance and minimal beam losses for high intensity ion beams. The cavity electromagnetic design uses optimizations not used before with QWR including a large taper on both the inner and outer conductors in order to reduce surface fields and make efficient use of space along the beam line. Electropolishing (EP) on the finished cavities with integral helium jacket and no demountable RF joints has been performed, and is the first for any low beta SC cavity. This type of EP, adapted from Argonne systems for the linear collider effort, appears to have a large benefit in terms of the average quench field which range between 103-165 mT for five QWR tested to date. Cavity residual resistances at the proposed operating point of ~70 mT are low, clustering close to a value of ~2nOhm. Additional technical details including the almost exclusive use of wire EDM for niobium fabrication and a new CW 4 kW RF power coupler are presented.

Slides THIOC01 [10.152 MB]

THIOC02

High Power CW Tests of cERL Main-Linac Cryomodule

cryomodule, cavity, HOM, alignment

855

H. Sakai, K. Enami, T. Furuya, M. Satoh, K. Shinoe, K. Umemori
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
M. Sawamura
JAEA, Ibaraki-ken, Japan

A main linac cryomodule have been constructed for Compact ERL project. It contains two 9-cell cavities, mounted with HOM absorbers and input couplers. After cavity string assembly, they were installed into the vacuum vessel of the cryomodule. It was placed inside radiation shield of cERL and connected to a refrigerator system. The cryomodule was successfully cooled down to 2K and low power and high power measurements were carried out.

Slides THIOC02 [12.842 MB]

THIOD01

SRF Cavities for ADS Project in China

cavity, SRF, proton, operation

868

Y. He, W.M. Yue, S.H. Zhang
IMP, Lanzhou, People's Republic of China
J.P. Dai, Z.Q. Li, Z.C. Liu, W.M. Pan
IHEP, Beijing, People's Republic of China
X.Y. Lu
PKU, Beijing, People's Republic of China

The driver linac for ADS project in China is full superconducting downstream of Radio Frequecy Quadrupole Accelerator. It is a key technology R&D stage of the project from 2011 to 2015. Superconducting HWR, Spoke, and elliptical cavities are all involved in the project. The prototypes of 162.5 MHz HWR010, 325 MHz Spoke012, 325 MHz Spoke021, 325 MHz Spoke040, and 650 MHz elliptical 063 are being developed at IMP and IHEP in China. A small number of HWR010 and Spoke012 have been produced and vertically tested. The first prototype of Spoke021 were tested too. The design, performances, fabrication, suface processing, and testing of all cavities will be presented in the talk. The design improvement of the cavities in the future will also be discussed.

Slides THIOD01 [13.465 MB]

THIOD02

Faced Issues in ReA3 Quarter-Wave Resonators and Their Successful Resolution

cavity, vacuum, cryomodule, operation

873

A. Facco
NSCL, East Lansing, Michigan, USA
C. Compton, J.L. Crisp, K. Elliott, A. Facco, M. Hodek, M.J. Johnson, M. Leitner, I.M. Malloch, D. Miller, S.J. Miller, D. Morris, D. Norton, R. Oweiss, J.P. Ozelis, J. Popielarski, L. Popielarski, K. Saito, N.R. Usher, G.J. Velianoff, D.R. Victory, J. Wei, K. Witgen, Y. Xu, S. Zhao
FRIB, East Lansing, Michigan, USA
A. Facco
INFN/LNL, Legnaro (PD), Italy

Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The 80.5 MHz, β=0.085 QWR production cavities for the ReA3 project at MSU have initially shown puzzling behavior and unexpected lack of performance. This was due to a combination of design problems and subtle mechanical effects which have been pointed out during a brief but intense testing campaign made by the FRIB SRF group. The same cavities could be eventually refurbished and brought to performance well above original specifications. This work will be presented with emphasis to the technical problems encountered, their diagnosis and the adopted solutions.

Slides THIOD02 [8.256 MB]

THIOD04

A Cold Tuner System With Mobile Plunger

cavity, simulation, insertion, cryomodule

884

D. Longuevergne, S. Blivet, S. Bousson, N. Gandolfo, G. Martinet, G. Olry, H. Saugnac
IPN, Orsay, France

Tuner systems for accelerating cavities are required to compensate static and dynamic frequency perturbations during beam operation. In the case of superconducting cavities, these are commonly tuned by deforming the cavity wall in specific places of the geometry. Nevertheless, considering the mechanical properties and frequency versus displacement sensitivity of some structures, tuning by deformation doesn’t allow to meet the requirements. In these specific cases, inspired from the “room temperature technology”, an alternative tuning technique by insertion of a helium-cooled superconducting plunger can be considered and has been studied for several projects (IFMIF, ESS-BILBAO). Advantages and drawbacks of such solution will be discussed and the successful results on SPIRAL2 cryomodule developed at IPNO will be presented.

Slides THIOD04 [4.938 MB]

THP001

Development of a Prototype SRF Cavity for the Proton Beam Utilization Facility at Nanjing University

cavity, HOM, SRF, proton

889

S. An, P.P. Xue
PLAI, Nanjing, People's Republic of China
S.Q.X. Xu, H. Z. Zhang
ADS-SRF, People's Republic of China
P.P. Xue, L. Zhang
Chang’an University, Chang'an, People's Republic of China
Z.R. Zhang
Nanjing University of Aeronautics and Astronautics, Jiangning, People's Republic of China

Nanjing University has initiated the new technology development in the field of high-energy, charged-particle beam application and fundamental sciences. A high-current proton accelerator used for the new energy, new technology and fundamental science applications platform will be the near term goal at Nanjing University. For developing the superconducting RF linac for the proton beam utilization at Nanjing University, the first 6-cell, medium-beta prototype superconducting RF cavity has been fabricated and demonstrated using Chinese vendors only. The low-power test has been completed. The vertical test will be carried out soon.

THP003

Cold Measurements on the 325 MHz CH-Cavity

cavity, coupling, ion, operation

896

M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany
M. Amberg
HIM, Mainz, Germany

Funding: GSI, BMBF Contr. No. 06FY7102, 06FY9089I
At the Institute for Applied Physics (IAP), Frankfurt University, a sc 325 MHz CH-Cavity has been designed and built. This 7-cell cavity has a geometrical beta of 0.16 corresponding to a beam energy of 11.4 AMeV. The design gradient is 5 MV/m. Novel features of this resonator are a compact design, low peak fields, easy surface processing and high power coupling. After successful tests at Research Instruments (RI) and in Frankfurt the cavity was processed and cleaned at RI and power tests at 4K have been performed at the cryo lab in Frankfurt. In this paper these measurements will be presented.

THP006

A Superconducting 217 MHz CH Cavitiy for the CW Demonstrator at GSI

cavity, solenoid, cryomodule, ion

906

F.D. Dziuba, M. Amberg, M. Busch, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany
M. Amberg, K. Aulenbacher, W.A. Barth, V. Gettmann, S. Mickat
HIM, Mainz, Germany
K. Aulenbacher
IKP, Mainz, Germany
W.A. Barth, S. Mickat
GSI, Darmstadt, Germany

Funding: Work supported by HIM, GSI, BMBF Contr. No. 05P12RFRBL
For a competitive production of new Super Heavy Elements (SHE) in the future a 7.3 AMeV superconducting (sc) continuous wave (cw) LINAC is planned at GSI. Currently, a cw demonstrator is going to be built up. The demonstrator consists of a sc 217 MHz Crossbar-H-mode (CH) cavity and two sc 9.5 T solenoids mounted in a horizontal cryostat. One major goal of the demonstrator project is to show the operation ability of sc CH cavity technology under a realistic accelerator environment. After first rf and cold tests the demonstrator will be tested with beam delivered by the GSI High Charge State Injector (HLI) in 2014.

THP007

Cornell's ERL Cavity Production

cavity, target, controls, cryomodule

909

R.G. Eichhorn, B. Bullock, B. Clasby, B. Elmore, F. Furuta, G.H. Hoffstaetter, J.J. Kaufman, B.M. Kilpatrick, J. Sears, V.D. Shemelin
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
T. Kürzeder
TU Darmstadt, Darmstadt, Germany

The phase 1 R&D program launched in preparation to building a 5 GeV Energy Recovery Linac (ERL) at Cornell, a full main linac cryomodule is currently built, housing six 7-cell cavities. In order to control the beam break-up limit, the shape of the cavity was highly optimized and stringent tolerances on the cavity production were targeted. We will report on the details of the cavity production, the accuracy of the cups forming the individual cells, the trimming procedure for the dumbbells, the cavity tuning and final accuracy of the cavity concerning field flatness, resonant frequency and overall length within this small series production.

THP013

A New Cavity Design for Medium Beta Acceleration

cavity, cryomodule, target, impedance

920

F.S. He, R.A. Rimmer, H. Wang
JLAB, Newport News, Virginia, USA

Funding: Work supported by DOE
Heavy duty or CW, superconducting proton and heavy ion accelerators are being proposed and constructed worldwide. The total length of the machine is one of the main drivers in terms of cost. Thus HWR and spoke cavities at medium beta are usually optimized to achieve low surface field and high gradient. A novel accelerating structure at β=0.5 evolved from spoke cavity is proposed, with lower surface fields but slightly higher heat load. It would be an interesting option for pulsed and CW accelerators with beam energy of more than 200MeV/u.

THP016

DEVELOPMENT OF THE SUPERCONDUCTING HALF WAVE RESONATOR FOR INJECTOR II IN C-ADS

cavity, niobium, simulation, proton

923

W.M. Yue, W. Chang, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, F.F. Wang, R.X. Wang, M.X. Xu, C. Zhang, S.H. Zhang, S.X. Zhang
IMP, Lanzhou, People's Republic of China

The Development of the Half Wave Resonator (HWR010) is based on the China ADS. The HWR010 operates at 162.5 MHz and can provide more than 0.78 MV of accelerating voltage per cavity for proton withβopt=0.10. We have designed the HWR010 in 2011. A copper model has been fabricated to test the HWR fabrication procedure. Five HWR010s have been fabricated in 2012. The HWR010s has finished the vertical testing and the Q0 is 4·10⁸ at Epeak = 45 MeV/m, and one of the HWR010s has been vertical tested with helium vessel. The slow tuner and high power coupler for this HWR have been developed and tested.

THP018

Design of a Superconducting 352MHz Fully Jacketed Double-Spoke Resonator for the ESS-Bilbao Proton Linac

cavity, cryomodule, simulation, DTL

929

T. Junquera
Accelerators and Cryogenic Systems, Orsay, France
F.J. Bermejo, J.L. Muñoz, A.V. Vélez
ESS Bilbao, Bilbao, Spain
P. Duchesne, G. Olry
IPN, Orsay, France

The baseline design for the ESS-Bilbao light-ion linear accelerator and neutron source (a facility compliant with the ESS-AB requirements) has been completed and the normal conducting section of the linac (RFQ and DTL) is at present under detailed design and construction. Starting at 50 MeV, it is proposed to follow this section with a superconducting section composed of double and triple spoke cavities grouped in cryomodules of 2 or 3 cavities reaching a maximum energy of 300 MeV. After an initial R&D program on spoke cavities with an aluminum model, detailed electromagnetic and mechanical studies of a beta 0.50, 352MHz, double spoke cavity were performed. The results of the calculations are presented in this paper. It is proposed to continue this development by the construction and test of the niobium cavities prototypes and initiating the study of a cryo-module with two cavities that could be tested with beam at the ESS-Bilbao facility.

THP019

1.3 GHz SRF Cavity Tests for ARIEL at TRIUMF

cavity, TRIUMF, HOM, SRF

933

P. Kolb, P.R. Harmer, D. Kishi, A. Koveshnikov, C. Laforge, D. Lang, R.E. Laxdal, Y. Ma, B.S. Waraich, Z.Y. Yao, V. Zvyagintsev
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

The 1.3 GHz cavity test program at TRIUMF for the ARIEL eLINAC progressed into its next stage: Going from single cell cavity tests to demonstrate the operating Q and gradient for ARIEL can be reached at TRIUMF to nine cell cavity tests for production cavities. Single cell cavity tests at TRIUMF showed a comparable performance to a characterization done on the same cavity at FNAL last year. These single cell tests showed that the operating point for ARIEL of Q0 > 10¹⁰ at 10 MV/m during 2 K operation can be reached and exceeded at TRIUMF. To prepare for the first ARIEL nine cell cavity, a test with a TESLA nine cell cavity was done. This included frequency and field tuning, etching via BCP, HPR and assembly in a class 10 clean environment as well as modifications to the cryo assembly and upgrades to the 2 K pumping system. The performance of this TESLA cavity and the performance of first ARIEL nine cell cavity produced by PAVAC will be shown.

THP021

Design of the SSR021 Cavity for the Proton Accelerator Main Linac of China ADS

cavity, proton, simulation, target

939

Z.Q. Li, Y.L. Chi, Q. Ma, W.M. Pan, Y. Sun, J.Y. Tang, Q.Y. Wang, B. Xu, X.Y. Zhang
IHEP, Beijing, People's Republic of China
Y. He, C. Zhang, S.H. Zhang, S.X. Zhang
IMP, Lanzhou, People's Republic of China
H.Y. Lin, P. Sha
Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China

China ADS is a high intensity proton machine based on CW superconducting technology. It includes two injectors and one main linac. The Institute of High Energy Physics (IHEP) and the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS), are responsible for developing the main linac together. This paper introduces the physics and mechanical design of the single spoke resonator (SSR021, beta021 cavity), which is used for first section of the main linac.

THP022

DEVELOPMENT OF A VERY LOW BETA SUPERCONDUCTING SINGLE SPOKE CAVITY FOR CHINA-ADS LINAC*

cavity, accelerating-gradient, LLRF, niobium

942

H. Li, J.P. Dai, L.H. Li, H.Y. Lin, Q. Ma, W.M. Pan, Y. Sun, Q.Y. Wang, J. Zhang
IHEP, Beijing, People's Republic of China
H. Huang, P. Sha
Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China

Twelve very low Beta superconducting single spoke cavities whose Beta is only 0.12 (Spoke012) operating at 325MHz, are adopted in Injector I for China-ADS linac. This type of spoke cavity is believed to be one of the key challenges for its very low geometric Beta. So far, collaborated with Peking University and Harbin Institute of Technology, IHEP has designed, fabricated and tested the spoke012 prototype cavity successfully. This paper presents the details of the design, fabrication and vertical test results for Spoke012 prototype cavity.

THP028

The Research on Spoke 0.40 Cavity

cavity, simulation, proton, superconducting-cavity

959

P. Sha, H. Huang
Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China
W.M. Pan, X.Y. Zhang
IHEP, Beijing, People's Republic of China

Spoke superconducting cavity can be used in the low-energy section of the proton accelerator. It has many significant advantages: compact structure, high value of R/Q, etc. The Chinese ADS (Accelerator Driven System) project will adopt many spoke cavities with 3 different β values (0.12, 0.21, 0.40). Spoke040 cavities (β=0.40) are used to increase the proton energy from 34 MeV to 178 MeV. Now the physical design of spoke040 cavity has been finished, and the machining are going on right now. The vertical test would be held at the end of this year.

THP052

Cornell’s Beam Line Higher Order Mode Absorbers

HOM, vacuum, cryomodule, damping

1027

R.G. Eichhorn, J.V. Conway, Y. He, Y. Li, T.I. O'Connel, P. Quigley, J. Sears, N.R.A. Valles
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
V.D. Shemelin
Cornell University, Ithaca, New York, USA

Efficient damping of the higher-order modes (HOMs) of the superconducting cavities is essential for the proposed energy recovery linac at Cornell that aims for high beam currents and short bunches. Designing these HOM beamline absorbers has been a long endeavor, sometimes including disappointing results. We will review the design, the findings on the prototype and the final choices made for the 7 HOM absorbers being built for the main linac cryomodule (MLC) prototype.

THP056

Validation Procedures for the IFMIF Power Coupler Prototypes

operation, vacuum, controls, target

1043

H. Jenhani, P. Carbonnier, Y. Gasser, N. Grouas, P. Hardy, V.M. Hennion, F. Orsini, Y. Penichot, B. Renard, D. Roudier
CEA/IRFU, Gif-sur-Yvette, France
S.J. Einarson, T.A. Treado
CPI, Beverley, Massachusetts, USA
D. Regidor, M. Weber
CIEMAT, Madrid, Spain

In the framework of the International Fusion Materials Irradiation Facility (IFMIF), which consists of two high power CW accelerator drivers, each delivering a 125 mA deuteron beam at 40 MeV, a Linear IFMIF Prototype Accelerator (LIPAc) is presently under design for the first phase of the project. The first two IFMIF Power Coupler Prototypes were manufactured for LIPAc. Series of acceptance tests have been performed successfully. Prototype Power Couplers have been then cleaned and assembled in an ISO 5 cleanroom. A dedicated test bench allowing RF conditioning of the couplers up to 200 kW CW at 175 MHz was achieved. RF power conditioning is planned to start during October 2013.

THP058

Update on the European XFEL RF Power Input Coupler

simulation, cryogenics, superconductivity, electron

1047

D. Kostin, W.-D. Möller
DESY, Hamburg, Germany
W. Kaabi
LAL, Orsay, France

European XFEL project is being currently realized in Hamburg, Germany. The 1.5 km 17.5 GeV linear electron accelerator is based on the 1.3GHz 9-cell TESLA type SRF cavity. The RF power input coupler design for the E-XFEL is based on well known TTF3 coupler design, used in FLASH accelerator. Coupler design was adapted for the industrial production with some parameters optimisation revisited and simulations done. Results are presented and discussed.

THP060

High Power RF Coupler for ADS Accelerating Cavities

cavity, simulation, operation, Windows

1055

S.V. Kutsaev, M.P. Kelly, B. Mustapha, J.A. Nolen, P.N. Ostroumov
ANL, Argonne, USA

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
Accelerator driven systems (ADS) require a high-power CW proton accelerator with proton beam energy near 1 GeV. High-gradient superconducting TEM-cavities are a natural choice for the front end of linac. This paper presents the design of superconducting low-beta half wave resonator operating at 162 MHz frequency for ADS, as well as a new 75 kW power coupler that has been designed at Argonne National Laboratory. This coupler would permit operations with an accelerating voltage of 3.0 MV with a beam current of 25 mA. The coupler includes a cold RF window which keeps the antenna at low temperature and a variable bellows section to adjust the coupling factor. The importance of these features for reliable operation will be discussed in detail.

THP064

HOM Couplers for CERN SPL Cavities

HOM, coupling, cavity, dipole

1066

K. Papke, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
F. Gerigk
CERN, Geneva, Switzerland

Funding: Work supported by the Wolfgang-Gentner-Programme of the Bundesministerium für Bildung und Forschung (BMBF)
Higher-Order-Modes (HOMs) may affect beam stability and refrigeration requirements of superconducting proton linacs such as the SPL, which is studied at CERN as the driver for future neutrino facilities. In order to limit beam-induced HOM effects CERN considers the use of HOM couplers on the cut-off tubes of the 5-cell superconducting cavities. These couplers consist of resonant antennas shaped as loops or probes which are designed to couple to modes of a specific frequency range. In this paper the design process is presented and a comparison is made between various design options for the medium and high-beta SPL cavities, both operating at 704 MHz. The RF characteristics, thermal behaviour and multipacting sensitivity of the various designs are discussed and 2 options are presented, which will be tested as warm prototypes on 5-cell high-beta copper cavity models.

THP066

SARAF Phase-I HWR Coupler Cooling Design

simulation, operation, cavity, proton

1073

J. Rodnizki, Y. Ben Aliz, I. Fishman, A. Grin, Z. Horvitz, B. Kaizer, L. Weissman
Soreq NRC, Yavne, Israel

The Soreq Applied Research Accelerator Facility (SARAF) design is based on a 40 MeV 5 mA light ions superconducting RF linac. Phase I of SARAF delivers up to 2 mA CW proton beam in an energy range of 1.5-4.5 MeV. The maximum beam power that we have reached is 4.5 kW. The warming of the SARAF linac RF couplers is currently the main limiting factor for reaching higher CW beam power. The coupler cooling configuration was optimized by increasing the cold window copper braid and adding a copper braid to the top end, using CST Multiphysics and ANSYS steady state and transient solvers. The study was conducted for the heat load generated by the surface currents of a matched 4 kW forward CW power, simulated by the CST MWS FD solver. Multipacting is a known potential heat source that overheats the coupler in the vicinity of the cold window. The coupler overheat phenomena was experimentally studied as a function of DC bias voltage, and it was found that a 900 V bias reduces significantly the heating rate. As a result we expect that the beam power can be significantly increased. The long overheat period implies that optimization of the cooling configuration is still needed.

THP070

Analysis of High Order Modes in 1.3 GHz CW SRF Electron Linac for a Light Source

HOM, cavity, dipole, emittance

1085

A.I. Sukhanov, A. Vostrikov, V.P. Yakovlev
Fermilab, Batavia, USA

Design of a Light Source (LS) based on the continuous wave superconducting RF (CW SRF) electron linac is currently underway. This facility will provide soft coherent X-ray radiation for a broad spectrum of basic research applications. Quality of the X-ray laser radiation is affected by the electron beam parameters such as the stability of the transverse beam position and longitudinal and transverse beam emittances. High order modes (HOMs) excited in the SRF structures by a passing beam may deteriorate the beam quality and affect the beam stability. Deposition of HOM energy in the walls of SRF cavities adds to the heat load of the cryogenic system and leads to the increased cost of building and operation of the linac. In this paper we evaluate effects of HOMs in an LS CW SRF linac based on Tesla-type 9-cell 1.3 GHz cavities. We analyze non-coherent losses and resonance excitation of HOMs. We estimate heat load due to the very high frequency HOMs. We study influence of the HOMs on the transverse beam dynamics.

THP071

HOM Studies of the Cornell ERL Main Linac Cavity in the Horizontal Test Cryomodule

HOM, cavity, cryomodule, experiment

1090

N.R.A. Valles, R.G. Eichhorn, D.A. Goldman, G.H. Hoffstaetter, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: Supported by NSF grant DMR-0807731
The Cornell energy recovery linac will accelerate a 100 mA beam to 5 GeV, while maintaining very low emittance (30 pm at 77 pC bunch charge). A major challenge to running such a large current continuously through the machine is the effect of strong higher-order modes (HOMs) in the SRF cavities that can lead to beam breakup. This paper presents the results of HOM studies for the prototype 7-cell cavity installed in a horizontal test cryomodule (HTC). HOM measurements were done for three HTC assembly stages, from initial measurements on the bare cavity to being fully outﬁtted with side-mounted RF input coupler and beam line HOM absorbers. We compare the simulated results of the optimized cavity geometry with measurements from all three HTC experiments, demonstrating excellent damping of all dipole higher order modes.

THP072

Input Coupler for Cornell ERL Main Linac

cavity, cryomodule, vacuum, operation

1094

V. Veshcherevich, P. Quigley
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: Work is supported by the National Science Foundation grant DMR-0807731.
Each cavity of the Cornell ERL Main Linac has a single coaxial type input coupler with fixed coupling, Qext = 6.5×E7. The input coupler will operate at RF power up to 5 kW at full reflection. The coupler design is based on the design of TTF-III input coupler with appropriate modifications and with taking into account the Cornell experience with couplers for ERL Injector. Seven couplers have been fabricated by CPI, Beverly and tested at Cornell on the test stand up to 5 kW CW. No major issues were noticed during the test. One coupler was attached to the prototype linac cavity. The cavity was successfully tested with great results achieved inside the horizontal test cryomodule. Six other couplers will be installed in the Main Linac Cryomodule (MLC) Prototype.

THP077

Coaxial Blade Tuner for European XFEL 3.9 GHz cavities

cavity, operation, simulation, cryomodule

1101

R. Paparella, M. Bertucci, A. Bosotti
INFN/LASA, Segrate (MI), Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy

The European XFEL linac injector features a third harmonic section jointly realized by INFN and DESY and hosting a 3.9 GHz 9-cell cavities cryomodule. The cold tuning system, developed by INFN for these cavities, is inspired by the coaxial Blade Tuner already qualified for ILC cavities. Design, fabrication and room temperature qualification of first tuner units produced are reviewed in this paper.

THP078

Deformation Tuner Design for a Double Spoke Cavity

cavity, operation, cryomodule, SRF

1104

N. Gandolfo, S. Bousson, S. Brault, P. Duchesne, P. Duthil, G. Olry, D. Reynet
IPN, Orsay, France

IPN Orsay is developing the low-beta double Spoke cavities cryomodule for the ESS. Based on previous successfully tested prototypes, a fast/slow tuner has been studied to compensate resonance frequency variations of the cavity during operation. The typical perturbations are coming from LHe pressure variations as well as microphonics and Lorentz force detuning (LFD). Two tuners are being built in order to validate both expected performances and series production feasibility. In this paper, the tuner design of the double Spoke cavity is presented.

THP079

Improvement of the Pneumatic Frequency Tuner of the Superconducting Resonators at IUAC

controls, cavity, vacuum, feedback

1107

A. Pandey, G.K. Chaudhari, R.N. Dutt, S. Ghosh, D. Kanjilal, J. Karmakar, D.S. Mathuria, P. Patra, A. Rai, A. Roy, B.K. Sahu, S.K. Saini
IUAC, New Delhi, India

The existing phase locking scheme of the quarter wave resonators used in superconducting linear accelerator of Inter University Accelerator Centre consists of a fast (electronic) and a slow time scale (pneumatic) control. Presently, helium gas operated mechanical tuners are being used to phase lock the resonators against the master oscillator frequency and different ion beams have been accelerated and delivered to conduct experiments. The present pneumatic frequency tuner has two limitations: (a) no proportional flow control in vacuum condition (b) large hysteresis problem in the proportional valve responsible for gas flow control. Due to these limitations, the system becomes non-linear and the response time is very slow (~sec). Using the existing system, phase locking of a resonator becomes delicate and time consuming. In addition, it was found to be difficult to implement auto phase locking mechanism on the resonator. To overcome these problems and to improve the dynamics of the existing tuner, a new pneumatic tuning system has been adopted. Details of the existing tuning mechanism and the modified tuning system along with the test results will be presented in the paper.

FRIOB01

SRF Cavities for Future Ion Linacs

cavity, cryomodule, ion, SRF

1183

Z.A. Conway, G.L. Cherry, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.H. Kim, S.V. Kutsaev, R.C. Murphy, B. Mustapha, P.N. Ostroumov, T. Reid
ANL, Argonne, USA

There is considerable interest worldwide in the applications of high-intensity (>5 mA) high-energy (>200 MeV) ion accelerators and the research which could be done with these machines. This presentation will present results of the three year ANL study funded specifically to make possible substantial reductions in the size and cost for future ion linacs in the region beta < 0.5. Applications include basic research, medical isotope production, and accelerator driven systems. High-performance low-beta resonators are key components of all of these machines. Recent 72.75 MHz, β = 0.077, quarter-wave resonator cold test results, designs and their impact on next generation ion accelerators are discussed. Peak fields in excess of 166 mT and 117 MV/m have been achieved and future work to improve upon this will be discussed.

Slides FRIOB01 [3.833 MB]

FRIOB04

CERN Developments for 704 MHz Superconducting Cavities

cavity, niobium, operation, proton

1198

O. Capatina, G. Arnau-Izquierdo, S. Atieh, I. Aviles Santillana, R. Bonomi, S. Calatroni, J.K. Chambrillon, R. Garoby, F. Gerigk, M. Guinchard, T. Junginger, M. Malabaila, L. Marques Antunes Ferreira, S. Mikulas, V. Parma, T. Renaglia, K.M. Schirm, T. Tardy, M. Therasse, A. Vacca, N. Valverde Alonso, A. Vande Craen
CERN, Geneva, Switzerland
F. Pillon
Kraftanlagen Nukleartechnik GmbH, Heidelberg, Germany

The Superconducting Proton Linac (SPL) is an R&D effort coordinated by CERN in partnership with other international laboratories. It is aiming at developing key technologies for the construction of a multi-megawatt proton linac based on state-of-the-art RF superconducting technology, which would serve as a driver in new physics facilities for neutrinos and/or Radioactive Ion Beam (RIB). Amongst the main objectives of this R&D effort, is the development of 704 MHz bulk niobium β=1 elliptical cavities, operating at 2 K with a maximum accelerating gradient of 25 MV/m, and the testing of a string of cavities integrated in a machine-type cryomodule. The cavity together with its helium tank had to be carefully designed in coherence with the innovative design of the cryomodule. New fabrication methods have also been explored. Five such niobium cavities and two copper cavities are in fabrication. The key design aspects are discussed, the results of the alternative fabrication methods presented and the status of the cavity manufacturing and surface preparation is detailed.

Slides FRIOB04 [8.677 MB]