IPAC2017 - Classification: 02 Photon Sources and Electron Accelerators / A08 Linear Accelerators

Paper	Title	Page
TUPAB012	Comparison of Prismatic and Circular Biperiodical Accelerating Structures of 27 GHz Operating Frequency	1330
	Yu.D. Kliuchevskaia, S.M. Polozov MEPhI, Moscow, Russia
	As known a biperiodical accelerating structure (BAS) represents as a system based on disk loaded waveguide (DLW) operating on Pi/2 mode and is widely used for the compact electron linacs. Earlier such structure with operating frequency of 27 GHz was proposed for medical application and beam dynamics simulations and electrodynamics modeling were done [1-2]. It was shown that such structure manufacturing should have very high accuracy and can be manufactured using electro erosive technology only. It is very complex for axi-symmetrical geometry to use such technology. Interesting option will to use a prismatic geometry BAS. In this report the design of a prismatic and disk-loaded BAS will discus, simulation results and analysis will presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB012
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB020	AREAL 50 MeV Electron Accelerator Project for THz and Middle IR FEL	1355
	G.A. Amatuni, Z.G. Amirkhanyan, V.S. Avagyan, A. Azatyan, V. Danielyan, H. Davtyan, S.G. Dekhtiarov, N. Ghazaryan, B. Grigoryan, L. Hakobyan, M. Ivanyan, V.G. Khachatryan, E.M. Laziev, T. Markosyan, N. Martirosyan, Sh.A. Mehrabyan, T. Melkumyan, T.H. Mkrtchyan, V.H. Petrosyan, V. Sahakyan, A. Sargsyan, A.S. Simonyan, A.V. Tsakanian, V.M. Tsakanov, A. Vardanyan, Ta.S. Vardanyan, T.L. Vardanyan, V. V. Vardanyan, A.S. Yeremyan, G.S. Zanyan CANDLE SRI, Yerevan, Armenia P.S. Manukyan SEUA, Yerevan, Armenia A.V. Tsakanian HZB, Berlin, Germany
	Advanced Research Electron Accelerator Laboratory (AREAL) is an electron accelerator project based on photo cathode RF gun. First phase of the facility is a 5 MeV energy RF photogun, which is currently under operation. The facility development implies energy upgrade to 50 MeV with further delivery of the electron beam to the undulator sections for Free Electron Laser and coherent undulator radiation generation in MIR and THz frequency ranges respectively. In this report the design study of AREAL 50 MeV facility main systems along with the beam dynamics and characteristics of expected radiation are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB022	TRIUMF ARIEL e-Linac Ready for 30 MeV	1361
	S.R. Koscielniak, Z.T. Ang, K. Fong, J.J. Keir, O.K. Kester, M.P. Laverty, R.E. Laxdal, Y. Ma, A.K. Mitra, T. Planche, D.W. Storey, E. Thoeng, B.S. Waraich, Z.Y. Yao, V. Zvyagintsev TRIUMF, Vancouver, Canada
	Funding: TRIUMF is funded under a contribution agreement with the National Research Council of Canada. The ARIEL electron linac (e-linac) in its present configuration has a 10 mA electron gun and a single-cavity 10 MeV injector cryomodule followed by the accelerator cryomodule intended to house two 10-MeV-capable SRF cavities. There are momentum analysis stations at 10 MeV and 30 MeV. In October 2014, using a total of two cavities, the e-linac demonstrated 22.9 MeV acceleration. In 2017 an additional SRF cavity was installed in the accelerator cryomodule, thereby completing its design specification; and leading to 30 MeV acceleration capability. The 9-cell 1.3 GHz cavities are a variant of the TESLA type, modified for c.w. operation and recirculation. An unusual feature of the module is the power feed of two cavities by one klystron through a wave-guide type power divider, and closed loop control of the combined voltage from the cavities. Initial operation of the two-cavity control, including power and phase balancing, is reported.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB022
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB023	Commissioning of the 10MeV Electron Injector Cryomodule for VECC at TRIUMF	1365
	R.E. Laxdal, Y. Ma, R.R. Nagimov, D.W. Storey, E. Thoeng, Z.Y. Yao, V. Zvyagintsev TRIUMF, Vancouver, Canada U. Bhunia, A. Chakrabarti, S. Dechoudhury, V. Naik VECC, Kolkata, India
	TRIUMF (Vancouver) and VECC (Kolkata) have been engaged in a collaboration on superconducting electron linacs since 2008. The motivation for the collaboration was to support initiatives at both labs, ARIEL at TRIUMF and ANURIB at VECC, to augment the respective radioactive ion beam (RIB) programs with the addition of a high intensity electron linac driver to produce RIBs through photo-fission. The common linac architecture is based on five 1.3GHz nine-cell SRF cavities housed in three cryomodules; a single cavity injector (ICM) and a pair of two cavity accelerating modules (ACM). Final design goals are 50MeV and 10mA/3mA at TRIUMF/VECC respectively. A ARIEL e-linac demonstrator with two cold cavities in two modules successfully accelerated beam to 20MeV. Recently the VECC 10MeV injector cryomodule was commissioned with beam. A summary of the ICM design and results of the commissioning will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB023
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB025	Experimental Results for Multiphoton Nonlinear Photoemission Processes on Phil Test Line	1369
	H. Purwar, C. Bruni, V. Chaumat, N. ElKamchi, V. Soskov LAL, Orsay, France D. Garzella CEA, Gif-sur-Yvette, France B. Lucas CNRS LPGP Univ Paris Sud, Orsay, France M. Pittman CLUPS, Orsay, France T. Vinatier DESY, Hamburg, Germany
	One of the prerequisites for the next generation high luminosity light sources is the availability of the short electron bunches. It also has several applications in other domains, including medical diagnostics and high-resolution imaging. In principle, using photoelectric effect a short electron bunch can initially be generated by illuminating a photocathode with an ultra-short light pulse of appropriate wavelength. Strong EM fields from a RF gun or similar accelerating structures, synchronized with the incoming laser pulses, are then used to accelerate these electron bunches initially up to an energy of tens of MeV. We present our preliminary results on the experimental investigation of two-photon nonlinear photoemission processes for the generation of picosecond, low-charge electron bunches conducted at PHIL photoinjector facility. A comparison of the emission efficiency and bunch characteristics with the single photon emission process is also made. *PHIL is an acronym for Photo-injector at Linear Accelerator Laboratory (LAL).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB025
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB030	Construction and Status of the Thrice Recirculating S-DALINAC	1384
	M. Arnold, R. Grewe, J. Pforr, N. Pietralla TU Darmstadt, Darmstadt, Germany C. Eschelbach, M. Lösler Frankfurt University of Applied Sciences, Frankfurt am Main, Germany F. Hug IKP, Mainz, Germany T. Kürzeder HIM, Mainz, Germany
	Funding: Work supported by DFG through RTG 2128 and CRC 634. From 1991 until 2015 the S-DALINAC (Superconducting-DArmstadt-LINear-ACcelerator) was operated as a twice recirculating electron accelerator. Its design energy of 130 MeV in cw-operation was not reached so far due to a lower quality factor of the SRF cavities and thus a higher dissipated power to the helium bath. In 2015/2016 a third recirculation has been built. Enabling a fourth passage through the main linac, the accelerating gradients can be reduced to fit the resulting dissipated power to the available cooling power for running at design energy. The upgrade to a thrice recirculating accelerator required the reconstruction of main parts of the existing lattice as well as an installation of a new beam line. All magnets had to be aligned carefully in position and orientation using high-precision metrology sensors. This contribution will present an overview of the construction and the alignment process. A latest status of the commissioning will be given.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB030
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB039	Installation Management for the European XFEL Main Accelerator	1409
	M. Bousonville, S. Choroba, F. Eints DESY, Hamburg, Germany
	By end of 2016, the main accelerator of the European XFEL was completed. To build this complex machine in a minimum of time, certain management methods were introduced in mid 2015, which accelerated the installation process substantially. In the following 64 weeks additional 84 % of the main accelerator were set up. This was possible due to an improved planning, the reinforcement of two teams as well as a permanent controlling and optimizing of the installation process. In this paper, the installation process from July 2015 to end 2016 and the measures which speeded up the workflow are described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB039
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB040	Status Update of the SINBAD-ARES Linac Under Construction at DESY	1412
	B. Marchetti, R.W. Aßmann, S. Baark, U. Dorda, C. Engling, K. Flöttmann, I. Hartl, J. Hauser, J. Herrmann, M. Hüning, M. Körfer, B. Krause, G. Kube, J. Kuhlmann, S. Lederer, F. Ludwig, D. Marx, F. Mayet, M. Pelzer, I. Peperkorn, A. Petrov, S. Pfeiffer, S. Pumpe, J. Rothenburg, H. Schlarb, M. Titberidze, S. Vilcins, M. Werner, Ch. Wiebers, L. Winkelmann, K. Wittenburg, J. Zhu DESY, Hamburg, Germany
	ARES (Accelerator Research Experiment at Sinbad) is a linear accelerator for the production of low charge (from few pC to sub-pC) electron bunches with 100 MeV energy, fs and sub-fs duration and excellent arrival time stability. This experiment is currently under construction at DESY Hamburg and it is foreseen to start operation by the beginning of 2018 with the commissioning of the RF-gun. After an initial beam characterization phase, ARES will provide high temporal resolution probes for testing novel acceleration techniques, such as Laser driven plasma Wake-Field Acceleration (LWFA), Dielectric Laser Acceleration (DLA) and THz driven acceleration. In this work we present an overview of the present design of the linac with a special focus on 3D integration and planned installation phases of the beamline.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB040
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB044	SIMULATION, MEASUREMENT AND TUNING OF A PROTOTYPE DISK LOADED RF CAVITY	1424
	S. Ahmadiannamin ILSF, Tehran, Iran F. Abbasi, F. Ghasemi Shahid Beheshti University, Tehran, Iran M. Lamehi, M. Shirshekan IPM, Tehran, Iran
	Constant impedance accelerator RF cavities are constructed from similar resonator cells that stacked to each other. Best operation condition is achieved when all of cells resonate in one resonance frequency with similar quality factors. So, measurement and tuning of RF cavities is the critical step for final best operation of linear accelerators. In this paper, the electromagnetic computer simulations, RF measurement and final tuning of a nine cell periodic accelerator structure was represented. All of cavities tuned in one resonant frequency and according to theoretical concepts we obtain nine resonant modes from RF measurements by vector network analyzer.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB044
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB045	Design and Construction of a Pre-Buncher for Iranian Low Energy Linear Accelerator	1428
	S. Ahmadiannamin ILSF, Tehran, Iran M. Bahrami, M.R. Khalvati, M. Lamehi, H. Shaker, M. Shirshekan IPM, Tehran, Iran
	Iranian IPM low energy linear accelerator project (e-Linac) is in its final steps for commissioning. Beam dynamic simulations with and without Pre-buncher prior to buncher was done. The results represent improvement in capturing efficiency better than 25% by application of Pre-buncher cavity. In this paper, we present the simulation, construction, RF measurements and vacuum test results. After construction, we measured RF reflection coefficient better than -33 dB in the nominal frequency of 2997.9 MHz with quality factor of 4500.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB045
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB048	Long Beam Pulses With SLED Compression in DAΦNE LINAC	1434
	P. Valente INFN-Roma, Roma, Italy M. Belli, B. Buonomo, R. Ceccarelli, A. Cecchinelli, R. Clementi, D.G.C. Di Giulio, L.G. Foggetta, G. Piermarini, L.A. Rossi, S. Strabioli, R. Zarlenga INFN/LNF, Frascati (Roma), Italy
	The DAΦNE LINAC is a ~60 m long, S-band (2856 MHz) linear accelerator, made up by four 45 MW klystrons with SLED compression, and by 15 travelling-wave, 2/3p, SLAC-type, 3 m long accelerating sections. It serves as injector of the DAΦNE e⁺ e⁻ collider, with 510 MeV, 10 ns long, electron and positron pulses, and the Beam-Test Facility extraction line, with variable beam energy and intensity and with pulses from 1.5 to 40 ns. A new pulsing system for the gun allows longer beam pulses, but the shape of the accelerating field in the sections due to the SLED compression has to be taken into account. We describe the tuning of the RF power, phase and delays in the pre-buncher, buncher and following accelerating sections, and the results of the tests performed in order to reach >200 ns 500 MeV electron pulses and the characterization of the quality of the beam in terms of energy spread, time distribution, etc.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB048
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB049	Development of the High Power Terahertz Light Sources at LEBRA Linac in Nihon University	1437
	T. Sakai, K. Hayakawa, Y. Hayakawa, K. Nogami, T. Tanaka LEBRA, Funabashi, Japan H. Ogawa, N. Sei AIST, Tsukuba, Ibaraki, Japan
	Funding: This work was supported by JSPS KAKENHI (Grant-in-Aid for Young Scientists (B)) Grant Number JP16K17539. Development of a THz light source has been underway at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University in collaboration with National Institute of Advanced Industrial Science and Technology (AIST) since 2011. Basic research on coherent transition radiation (CTR) in the THz region has been carried out using the Parametric X-ray Radiation (PXR)-beam line of LEBRA. Since fiscal year 2016, the THz transport line has been constructed on the same axis as the PXR beam line taking the construction cost and simultaneous use of the two beams into account. Basic measurement and intensity upgrading test have been carried out for the THz lights generated on the PXR-generating electron beam line. The average intensity of the THz lights obtained at the output port in the accelerator room has been 5 mW. Construction of the THz transport beam line and the property of the THz lights is discussed in the report.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB049
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB070	S-Band Accelerating Structure for High-Gradient Upgrade of TTX	1485
	D.Z. Cao, H.B. Chen, Y.-C. Du, W. Gai, W.-H. Huang, X.C. Meng, J. Shi, C.-X. Tang, X.W. Wu, H. Zha TUB, Beijing, People's Republic of China
	Thomson scattering x-ray source is an indispensable scientific X-ray imaging tool in various research fields. The 3-meter S-band linac in Tsinghua Thomson scatter-ing X-ray source (TTX) has been running at an accelerat-ing gradient of 15 MV/m so far. The gradient will be upgraded to 30MV/m by replacing the old structure with a shorter linac. Detailed optimization of the RF design of the new S-band linac structure is presented in this paper. Finally, further research on energy upgrade with X-band structures are also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB070
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB075	Compact High Energy Electron Radiography System Based on Permanent Magnet Quadrupole	1494
	Z. Zhou, Y.-C. Du, W. Gai, W.-H. Huang, F. Li, T. Rui, C.-X. Tang TUB, Beijing, People's Republic of China W. Gai ANL, Argonne, Illinois, USA
	High energy electron radiography(HEER) is a promising diagnostic method for High Energy Density Physics (HEDP) or Inertial Confinement Fusion (ICF) owing to its capability of picosecond-nanometer spatio-temporal resolution, and is cost-effective in the meantime. A Compact HEER (CHEER) system based on Permanent Magnet Quadrupoles (PMQ) instead of conventional electromagnetic quadrupole is proposed. Its lattice design and beam optics optimization is finished, and experiment is to be carried out on Tsinghua Thomson X-ray source (TTX) beamline after PMQs fabrication and installation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB075
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB077	A Combined THz/X-ray Source Based on Brake-applied Velocity Bunching and Magnetic Compression	1500
	R. Huang, Z.G. He, Q.K. Jia, B. Li, W.W. Li, L. Wang, S.C. Zhang USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Work supported by Chinese Universities Scientific Fund under Contracts WK2310000063 and WK2310000047 Ultrashort electron beam can be realized by the process of velocity bunching and magnetic compression. Velocity bunching technique is able to compress the bunch at relatively low energy, which presents peculiar challenges when approaching a very high current and a low transverse emittance in photoinjectors. A brake-applied velocity bunching scheme was proposed, so that the transverse emittance of the beam could be almost compensated even if the compression factor was extremely high. By adding a magnetic compressor, one could obtain a shorter beam and achieve the coherent synchrotron radiation in THz range. Meanwhile, when making the final compressed beam collide with the laser, one could acquire high energy X-ray pulses. This opens the possibility for some interesting combinations of pump-and-probe experiments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB077
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB082	Research of L-Band Disk-Loaded Waveguides Travelling Wave Accelerating Structures for a High Power Linac	1506
	Y.M. Zhang USTC, SNST, Anhui, People's Republic of China Y.J. Pei, L.S. Sheng, Y. Song USTC/NSRL, Hefei, Anhui, People's Republic of China
	L-band Electron Accelerator is widely used for industrial irradiation. This paper describes a constant-impedance, disk-loaded structure operating on the 2Pi/3 mode. The design details of L-band travelling wave accelerating structures are presented. All RF parameters in metal disk-loaded waveguides and fields were calculated. The SUPERFISH code was used to design the bunching and accelerating cavities. At the same time, we also calculated the beam dynamics. Some model cavities have been fabricated and experimental studies were carried on. In this study, some valuable results were obtained, which can provide a beneficial datum for the design and manufacture of L-band travelling-wave accelerating structures of 50MeV LINAC.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB082
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB083	Commissioning Experience and Beam Optimization for DCLS Linac	1509
	M. Zhang, D. Gu, Q. Gu, D. Huang, Z. Wang SINAP, Shanghai, People's Republic of China
	Dalian Coherent Light Source (DCLS), which will focus on the Physical Chemistry with time-resolved pump-probe experiments and EUV absorption spectroscopy techniques, is the first high gain FEL user facility in China. The 300MeV linac consists of a laser-driven rf-gun followed by 7 Sband accelerating tubes. A magnetic chicane is adopted to get the desired 300A peak current. After 5 months component installation, first photoelectrons were generated on 17 August 2016. In this paper, we give a summary of the commissioning experience and the beam parameters measurements. In addition, beam jitter sources are studied based on real machine performances.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB083
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB084	Beam Stability Modeling and Jitter Control for SXFEL Linac	1513
	M. Zhang, R.B. Deng, D. Gu, Q. Gu, D. Huang, Z. Wang SINAP, Shanghai, People's Republic of China
	FEL operations foresee stringent requirements for the stability of the global linac output parameters and this requirement is particularly stringent for the successful operation of an externally seeded FEL. In order to understand the sensitivity of these parameters to jitters of various error sources along the SXFEL linac, studies have been performed based on analytical methods and tracking code simulations. Using the tolerance budget as guidance, beam jitter control techniques are discussed on the view of the beam dynamics.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB084
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB099	Status of MAX IV Linac Beam Commissioning and Performance	1547
	S. Thorin, J. Andersson, M. Brandin, F. Curbis, L. Isaksson, M. Kotur, D. Kumbaro, F. Lindau, E. Mansten, D. Olsson, R. Svärd, S. Werin MAX IV Laboratory, Lund University, Lund, Sweden J. Björklund Svensson Lund University, Division of Atomic Physics, Lund, Sweden
	The MAX IV linac is used both for full energy injection into two storage rings at 3 GeV and 1.5 GeV, and as a high brightness driver for a Short Pulse Facility (SPF). The linac has also been designed to handle the high demands of an FEL injector. The linac is now routinely injecting into the two storage rings, and commissioning work is focused towards delivering high brightness pulses to the SPF. In this paper we present results from characterisation of the linac in ring injection mode, as well as results from measurements of key parameters for the SPF such as bunch length and emittance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB099
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB130	Status of the LCLS-II Superconducting RF Linac	1630
	A. Burrill SLAC, Menlo Park, California, USA
	The LCLS-II project requires the assembly and installation of 37 cryomodules in order to deliver a 4 GeV electron beam to the undulators to produce both soft and hard x-ray pulses at a repetition rate up to 1 MHz. All of the cryomodules will operate in continuous wave mode, with 35 operating at 1.3 GHz for acceleration and 2 operating at 3.9 GHz to linearize the longitudinal beam profile. The assembly and testing of the 1.3 GHz cryomodules is well underway and the 3.9 GHz cryomodule work is entering into the pre-cryomodule testing and component validation phase. Both of these efforts will be reported on in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB130
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB132	A Novel Dual-Mode Dual-Frequency Linac Design	1634
SUSPSIK123	use link to see paper's listing under its alternate paper code
	M.H. Nasr, S.G. Tantawi SLAC, Menlo Park, California, USA
	In this paper we will present a new type of accelerator structure that operates simultaneously at two accelerating modes with two frequencies. The frequencies are not harmonically related, but rather have a common sub-harmonic. This design will use a recently developed parallel-feeding network that feeds every cavity cell independently using a distributed feeding network. This will overcome many of the practical complications of coupled cell structure. We will provide the theoretical background for our dual-mode design as well as present our optimized design that operates at C and X bands simultaneously and provides enhanced gradient and efficiency compared to single-mode designs.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB132
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB142	Tracking of Electrons Created at Wrong RF Phases in the RHIC Low Energy Cooler	1666
	J. Kewisch, A.V. Fedotov, D. Kayran, S. Seletskiy BNL, Upton, Long Island, New York, USA
	Funding: Work supported by the US Department of Energy under contract No. DE-SC0012704. The RHIC Low Energy Cooler will be based on a 400 keV DC electron gun with a photo-cathode and a 2.2 MeV SRF booster cavity. Electron that leave the cathode at the wrong time may be decelerated and turned around in the booster and return to the cathode with energies up to 1 MeV. On the way back these electron will encounter the defocussing EM fields up to nine following electron bunches. Such electrons may be created for various reasons: Cosmic rays, stray laser light including a catastrophic failure of the laser timing system or as secondaries of returning electrons. We present tracking results from the GPT program* and discuss the consequences for the machine protection system. * www.pulsar.nl
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB142
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB143	Dependence of LEReC Beam Energy Spread on Photocathode Laser Modulation	1669
	S. Seletskiy, M. Blaskiewicz, A.V. Fedotov, D. Kayran, J. Kewisch, M.G. Minty, B. Sheehy, Z. Zhao BNL, Upton, Long Island, New York, USA B. Sheehy Sheehy Scientific Consulting, Wading River, New York, USA
	Present requirements to the photocathode DC gun of the low energy RHIC electron cooling (LEReC) project is to produce 100 ps long bunch of electrons with 130 pC charge. The laser pulse of required length will be produced with the stacking of multiple few picosecond long sub-pulses. Depending on the choice of the laser sub-pulse length and on the relative delay between these sub-pulses one can obtain laser pulse with various longitudinal intensity modulations. The longitudinal modulation of laser intensity creates longitudinal modulation of electron bunch charge. Such modulation is known to cause the growth of e-beam uncorrelated energy spread in photoinjectors - the effect we would like to avoid. In this paper we estimate growth of e-beam energy spread due to its initial density modulation and set requirements to the maximum allowable depth of longitudinal modulation of photocathode laser intensity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB143
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPIK033	Test and Commissioning Results of NSC KIPT 100 MeV/ 100 kW Electron Linear Accelerator, Subcritical Neutron Source Driver	1751
	A.Y. Zelinsky, O.E. Andreev, V.P. Androsov, S.V. Bazarov, O. Bezditko, O.V. Bykhun, Y.L. Chi, A.N. Gordienko, V.A. Grevtsev, A. Gvozd, D.Y. He, X. He, V.E. Ivashchenko, A.A. Kalamayko, I.I. Karnaukhov, I.M. Karnaukhov, X.C. Kong, V.P. Lyashchenko, H.Z. Ma, M. Moisieienko, S. Pei, X.H. Peng, A.V. Reuzayev, I.M. Subotenko, D.V. Tarasov, V.I. Trotsenko, X. Wang NSC/KIPT, Kharkov, Ukraine Y.L. Chi, D.Y. He, X. He, X.C. Kong, H.Z. Ma, S. Pei, X.H. Peng, X. Wang IHEP, Beijing, People's Republic of China S. Shu Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China
	Neutron Source on the base of subcritical assembly has been constructed and is under commissioning in NSC KIPT, Kharkov, Ukraine. The source uses 100 MeV/ 100 kW electron linear accelerator as a driver. The accelerator was designed and manufactured in IHEP, Beijing, China. The accelerator has been assembled at NSC KIPT, all accelerator systems and components were and accelerator is under commissioning. Reports describes the status of the NSC KIPT 100 MeV/ 100 kW electron linear accelerator. The results of the first tests are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK033
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPIK104	Effects of Non-axisymmetric Solenoid Field on Beam Quality in Velocity Bunching	1958
	Y.H. Wen NTHU, Hsinchu, Taiwan C.H. Chen, N.Y. Huang, W.K. Lau, A.P. Lee NSRRC, Hsinchu, Taiwan
	Space-charge effect is not negligible during the early stage of beam acceleration in a photoinjector rf linac that is operated for generation of short electron pulses by velocity bunching. A solenoid with iron shield can be used to provide the required axis-symmetric magnetic field to balance the radial space-charge force of the beam. However, the iron shield cannot be perfectly symmetric because openings are reserved for feeding water pipes and electrical cables to the coils. In addition, alignment errors of the solenoid may also spoil the symmetry of the focusing field. In this study, simulation is carried out to investigate how does the non-axisymmetric solenoid field of different origins influence beam properties, such as beam size, transverse emittance during the rf bunch compression.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK104
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Comparison of Prismatic and Circular Biperiodical Accelerating Structures of 27 GHz Operating Frequency

1330

Yu.D. Kliuchevskaia, S.M. Polozov
MEPhI, Moscow, Russia

As known a biperiodical accelerating structure (BAS) represents as a system based on disk loaded waveguide (DLW) operating on Pi/2 mode and is widely used for the compact electron linacs. Earlier such structure with operating frequency of 27 GHz was proposed for medical application and beam dynamics simulations and electrodynamics modeling were done [1-2]. It was shown that such structure manufacturing should have very high accuracy and can be manufactured using electro erosive technology only. It is very complex for axi-symmetrical geometry to use such technology. Interesting option will to use a prismatic geometry BAS. In this report the design of a prismatic and disk-loaded BAS will discus, simulation results and analysis will presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB012

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB020

AREAL 50 MeV Electron Accelerator Project for THz and Middle IR FEL

1355

G.A. Amatuni, Z.G. Amirkhanyan, V.S. Avagyan, A. Azatyan, V. Danielyan, H. Davtyan, S.G. Dekhtiarov, N. Ghazaryan, B. Grigoryan, L. Hakobyan, M. Ivanyan, V.G. Khachatryan, E.M. Laziev, T. Markosyan, N. Martirosyan, Sh.A. Mehrabyan, T. Melkumyan, T.H. Mkrtchyan, V.H. Petrosyan, V. Sahakyan, A. Sargsyan, A.S. Simonyan, A.V. Tsakanian, V.M. Tsakanov, A. Vardanyan, Ta.S. Vardanyan, T.L. Vardanyan, V. V. Vardanyan, A.S. Yeremyan, G.S. Zanyan
CANDLE SRI, Yerevan, Armenia
P.S. Manukyan
SEUA, Yerevan, Armenia
A.V. Tsakanian
HZB, Berlin, Germany

Advanced Research Electron Accelerator Laboratory (AREAL) is an electron accelerator project based on photo cathode RF gun. First phase of the facility is a 5 MeV energy RF photogun, which is currently under operation. The facility development implies energy upgrade to 50 MeV with further delivery of the electron beam to the undulator sections for Free Electron Laser and coherent undulator radiation generation in MIR and THz frequency ranges respectively. In this report the design study of AREAL 50 MeV facility main systems along with the beam dynamics and characteristics of expected radiation are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB020

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB022

TRIUMF ARIEL e-Linac Ready for 30 MeV

1361

S.R. Koscielniak, Z.T. Ang, K. Fong, J.J. Keir, O.K. Kester, M.P. Laverty, R.E. Laxdal, Y. Ma, A.K. Mitra, T. Planche, D.W. Storey, E. Thoeng, B.S. Waraich, Z.Y. Yao, V. Zvyagintsev
TRIUMF, Vancouver, Canada

Funding: TRIUMF is funded under a contribution agreement with the National Research Council of Canada.
The ARIEL electron linac (e-linac) in its present configuration has a 10 mA electron gun and a single-cavity 10 MeV injector cryomodule followed by the accelerator cryomodule intended to house two 10-MeV-capable SRF cavities. There are momentum analysis stations at 10 MeV and 30 MeV. In October 2014, using a total of two cavities, the e-linac demonstrated 22.9 MeV acceleration. In 2017 an additional SRF cavity was installed in the accelerator cryomodule, thereby completing its design specification; and leading to 30 MeV acceleration capability. The 9-cell 1.3 GHz cavities are a variant of the TESLA type, modified for c.w. operation and recirculation. An unusual feature of the module is the power feed of two cavities by one klystron through a wave-guide type power divider, and closed loop control of the combined voltage from the cavities. Initial operation of the two-cavity control, including power and phase balancing, is reported.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB022

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB023

Commissioning of the 10MeV Electron Injector Cryomodule for VECC at TRIUMF

1365

R.E. Laxdal, Y. Ma, R.R. Nagimov, D.W. Storey, E. Thoeng, Z.Y. Yao, V. Zvyagintsev
TRIUMF, Vancouver, Canada
U. Bhunia, A. Chakrabarti, S. Dechoudhury, V. Naik
VECC, Kolkata, India

TRIUMF (Vancouver) and VECC (Kolkata) have been engaged in a collaboration on superconducting electron linacs since 2008. The motivation for the collaboration was to support initiatives at both labs, ARIEL at TRIUMF and ANURIB at VECC, to augment the respective radioactive ion beam (RIB) programs with the addition of a high intensity electron linac driver to produce RIBs through photo-fission. The common linac architecture is based on five 1.3GHz nine-cell SRF cavities housed in three cryomodules; a single cavity injector (ICM) and a pair of two cavity accelerating modules (ACM). Final design goals are 50MeV and 10mA/3mA at TRIUMF/VECC respectively. A ARIEL e-linac demonstrator with two cold cavities in two modules successfully accelerated beam to 20MeV. Recently the VECC 10MeV injector cryomodule was commissioned with beam. A summary of the ICM design and results of the commissioning will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB023

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB025

Experimental Results for Multiphoton Nonlinear Photoemission Processes on Phil Test Line

1369

H. Purwar, C. Bruni, V. Chaumat, N. ElKamchi, V. Soskov
LAL, Orsay, France
D. Garzella
CEA, Gif-sur-Yvette, France
B. Lucas
CNRS LPGP Univ Paris Sud, Orsay, France
M. Pittman
CLUPS, Orsay, France
T. Vinatier
DESY, Hamburg, Germany

One of the prerequisites for the next generation high luminosity light sources is the availability of the short electron bunches. It also has several applications in other domains, including medical diagnostics and high-resolution imaging. In principle, using photoelectric effect a short electron bunch can initially be generated by illuminating a photocathode with an ultra-short light pulse of appropriate wavelength. Strong EM fields from a RF gun or similar accelerating structures, synchronized with the incoming laser pulses, are then used to accelerate these electron bunches initially up to an energy of tens of MeV. We present our preliminary results on the experimental investigation of two-photon nonlinear photoemission processes for the generation of picosecond, low-charge electron bunches conducted at PHIL photoinjector facility. A comparison of the emission efficiency and bunch characteristics with the single photon emission process is also made.
*PHIL is an acronym for Photo-injector at Linear Accelerator Laboratory (LAL).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB025

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB030

Construction and Status of the Thrice Recirculating S-DALINAC

1384

M. Arnold, R. Grewe, J. Pforr, N. Pietralla
TU Darmstadt, Darmstadt, Germany
C. Eschelbach, M. Lösler
Frankfurt University of Applied Sciences, Frankfurt am Main, Germany
F. Hug
IKP, Mainz, Germany
T. Kürzeder
HIM, Mainz, Germany

Funding: Work supported by DFG through RTG 2128 and CRC 634.
From 1991 until 2015 the S-DALINAC (Superconducting-DArmstadt-LINear-ACcelerator) was operated as a twice recirculating electron accelerator. Its design energy of 130 MeV in cw-operation was not reached so far due to a lower quality factor of the SRF cavities and thus a higher dissipated power to the helium bath. In 2015/2016 a third recirculation has been built. Enabling a fourth passage through the main linac, the accelerating gradients can be reduced to fit the resulting dissipated power to the available cooling power for running at design energy. The upgrade to a thrice recirculating accelerator required the reconstruction of main parts of the existing lattice as well as an installation of a new beam line. All magnets had to be aligned carefully in position and orientation using high-precision metrology sensors. This contribution will present an overview of the construction and the alignment process. A latest status of the commissioning will be given.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB030

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB039

Installation Management for the European XFEL Main Accelerator

1409

M. Bousonville, S. Choroba, F. Eints
DESY, Hamburg, Germany

By end of 2016, the main accelerator of the European XFEL was completed. To build this complex machine in a minimum of time, certain management methods were introduced in mid 2015, which accelerated the installation process substantially. In the following 64 weeks additional 84 % of the main accelerator were set up. This was possible due to an improved planning, the reinforcement of two teams as well as a permanent controlling and optimizing of the installation process. In this paper, the installation process from July 2015 to end 2016 and the measures which speeded up the workflow are described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB039

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB040

Status Update of the SINBAD-ARES Linac Under Construction at DESY

1412

B. Marchetti, R.W. Aßmann, S. Baark, U. Dorda, C. Engling, K. Flöttmann, I. Hartl, J. Hauser, J. Herrmann, M. Hüning, M. Körfer, B. Krause, G. Kube, J. Kuhlmann, S. Lederer, F. Ludwig, D. Marx, F. Mayet, M. Pelzer, I. Peperkorn, A. Petrov, S. Pfeiffer, S. Pumpe, J. Rothenburg, H. Schlarb, M. Titberidze, S. Vilcins, M. Werner, Ch. Wiebers, L. Winkelmann, K. Wittenburg, J. Zhu
DESY, Hamburg, Germany

ARES (Accelerator Research Experiment at Sinbad) is a linear accelerator for the production of low charge (from few pC to sub-pC) electron bunches with 100 MeV energy, fs and sub-fs duration and excellent arrival time stability. This experiment is currently under construction at DESY Hamburg and it is foreseen to start operation by the beginning of 2018 with the commissioning of the RF-gun. After an initial beam characterization phase, ARES will provide high temporal resolution probes for testing novel acceleration techniques, such as Laser driven plasma Wake-Field Acceleration (LWFA), Dielectric Laser Acceleration (DLA) and THz driven acceleration. In this work we present an overview of the present design of the linac with a special focus on 3D integration and planned installation phases of the beamline.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB040

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB044

SIMULATION, MEASUREMENT AND TUNING OF A PROTOTYPE DISK LOADED RF CAVITY

1424

S. Ahmadiannamin
ILSF, Tehran, Iran
F. Abbasi, F. Ghasemi
Shahid Beheshti University, Tehran, Iran
M. Lamehi, M. Shirshekan
IPM, Tehran, Iran

Constant impedance accelerator RF cavities are constructed from similar resonator cells that stacked to each other. Best operation condition is achieved when all of cells resonate in one resonance frequency with similar quality factors. So, measurement and tuning of RF cavities is the critical step for final best operation of linear accelerators. In this paper, the electromagnetic computer simulations, RF measurement and final tuning of a nine cell periodic accelerator structure was represented. All of cavities tuned in one resonant frequency and according to theoretical concepts we obtain nine resonant modes from RF measurements by vector network analyzer.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB044

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB045

Design and Construction of a Pre-Buncher for Iranian Low Energy Linear Accelerator

1428

S. Ahmadiannamin
ILSF, Tehran, Iran
M. Bahrami, M.R. Khalvati, M. Lamehi, H. Shaker, M. Shirshekan
IPM, Tehran, Iran

Iranian IPM low energy linear accelerator project (e-Linac) is in its final steps for commissioning. Beam dynamic simulations with and without Pre-buncher prior to buncher was done. The results represent improvement in capturing efficiency better than 25% by application of Pre-buncher cavity. In this paper, we present the simulation, construction, RF measurements and vacuum test results. After construction, we measured RF reflection coefficient better than -33 dB in the nominal frequency of 2997.9 MHz with quality factor of 4500.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB045

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB048

Long Beam Pulses With SLED Compression in DAΦNE LINAC

1434

P. Valente
INFN-Roma, Roma, Italy
M. Belli, B. Buonomo, R. Ceccarelli, A. Cecchinelli, R. Clementi, D.G.C. Di Giulio, L.G. Foggetta, G. Piermarini, L.A. Rossi, S. Strabioli, R. Zarlenga
INFN/LNF, Frascati (Roma), Italy

The DAΦNE LINAC is a ~60 m long, S-band (2856 MHz) linear accelerator, made up by four 45 MW klystrons with SLED compression, and by 15 travelling-wave, 2/3p, SLAC-type, 3 m long accelerating sections. It serves as injector of the DAΦNE e⁺ e⁻ collider, with 510 MeV, 10 ns long, electron and positron pulses, and the Beam-Test Facility extraction line, with variable beam energy and intensity and with pulses from 1.5 to 40 ns. A new pulsing system for the gun allows longer beam pulses, but the shape of the accelerating field in the sections due to the SLED compression has to be taken into account. We describe the tuning of the RF power, phase and delays in the pre-buncher, buncher and following accelerating sections, and the results of the tests performed in order to reach >200 ns 500 MeV electron pulses and the characterization of the quality of the beam in terms of energy spread, time distribution, etc.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB048

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB049

Development of the High Power Terahertz Light Sources at LEBRA Linac in Nihon University

1437

T. Sakai, K. Hayakawa, Y. Hayakawa, K. Nogami, T. Tanaka
LEBRA, Funabashi, Japan
H. Ogawa, N. Sei
AIST, Tsukuba, Ibaraki, Japan

Funding: This work was supported by JSPS KAKENHI (Grant-in-Aid for Young Scientists (B)) Grant Number JP16K17539.
Development of a THz light source has been underway at Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University in collaboration with National Institute of Advanced Industrial Science and Technology (AIST) since 2011. Basic research on coherent transition radiation (CTR) in the THz region has been carried out using the Parametric X-ray Radiation (PXR)-beam line of LEBRA. Since fiscal year 2016, the THz transport line has been constructed on the same axis as the PXR beam line taking the construction cost and simultaneous use of the two beams into account. Basic measurement and intensity upgrading test have been carried out for the THz lights generated on the PXR-generating electron beam line. The average intensity of the THz lights obtained at the output port in the accelerator room has been 5 mW. Construction of the THz transport beam line and the property of the THz lights is discussed in the report.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB049

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB070

S-Band Accelerating Structure for High-Gradient Upgrade of TTX

1485

D.Z. Cao, H.B. Chen, Y.-C. Du, W. Gai, W.-H. Huang, X.C. Meng, J. Shi, C.-X. Tang, X.W. Wu, H. Zha
TUB, Beijing, People's Republic of China

Thomson scattering x-ray source is an indispensable scientific X-ray imaging tool in various research fields. The 3-meter S-band linac in Tsinghua Thomson scatter-ing X-ray source (TTX) has been running at an accelerat-ing gradient of 15 MV/m so far. The gradient will be upgraded to 30MV/m by replacing the old structure with a shorter linac. Detailed optimization of the RF design of the new S-band linac structure is presented in this paper. Finally, further research on energy upgrade with X-band structures are also discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB070

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB075

Compact High Energy Electron Radiography System Based on Permanent Magnet Quadrupole

1494

Z. Zhou, Y.-C. Du, W. Gai, W.-H. Huang, F. Li, T. Rui, C.-X. Tang
TUB, Beijing, People's Republic of China
W. Gai
ANL, Argonne, Illinois, USA

High energy electron radiography(HEER) is a promising diagnostic method for High Energy Density Physics (HEDP) or Inertial Confinement Fusion (ICF) owing to its capability of picosecond-nanometer spatio-temporal resolution, and is cost-effective in the meantime. A Compact HEER (CHEER) system based on Permanent Magnet Quadrupoles (PMQ) instead of conventional electromagnetic quadrupole is proposed. Its lattice design and beam optics optimization is finished, and experiment is to be carried out on Tsinghua Thomson X-ray source (TTX) beamline after PMQs fabrication and installation.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB075

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB077

A Combined THz/X-ray Source Based on Brake-applied Velocity Bunching and Magnetic Compression

1500

R. Huang, Z.G. He, Q.K. Jia, B. Li, W.W. Li, L. Wang, S.C. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Work supported by Chinese Universities Scientific Fund under Contracts WK2310000063 and WK2310000047
Ultrashort electron beam can be realized by the process of velocity bunching and magnetic compression. Velocity bunching technique is able to compress the bunch at relatively low energy, which presents peculiar challenges when approaching a very high current and a low transverse emittance in photoinjectors. A brake-applied velocity bunching scheme was proposed, so that the transverse emittance of the beam could be almost compensated even if the compression factor was extremely high. By adding a magnetic compressor, one could obtain a shorter beam and achieve the coherent synchrotron radiation in THz range. Meanwhile, when making the final compressed beam collide with the laser, one could acquire high energy X-ray pulses. This opens the possibility for some interesting combinations of pump-and-probe experiments.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB077

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB082

Research of L-Band Disk-Loaded Waveguides Travelling Wave Accelerating Structures for a High Power Linac

1506

Y.M. Zhang
USTC, SNST, Anhui, People's Republic of China
Y.J. Pei, L.S. Sheng, Y. Song
USTC/NSRL, Hefei, Anhui, People's Republic of China

L-band Electron Accelerator is widely used for industrial irradiation. This paper describes a constant-impedance, disk-loaded structure operating on the 2Pi/3 mode. The design details of L-band travelling wave accelerating structures are presented. All RF parameters in metal disk-loaded waveguides and fields were calculated. The SUPERFISH code was used to design the bunching and accelerating cavities. At the same time, we also calculated the beam dynamics. Some model cavities have been fabricated and experimental studies were carried on. In this study, some valuable results were obtained, which can provide a beneficial datum for the design and manufacture of L-band travelling-wave accelerating structures of 50MeV LINAC.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB082

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB083

Commissioning Experience and Beam Optimization for DCLS Linac

1509

M. Zhang, D. Gu, Q. Gu, D. Huang, Z. Wang
SINAP, Shanghai, People's Republic of China

Dalian Coherent Light Source (DCLS), which will focus on the Physical Chemistry with time-resolved pump-probe experiments and EUV absorption spectroscopy techniques, is the first high gain FEL user facility in China. The 300MeV linac consists of a laser-driven rf-gun followed by 7 Sband accelerating tubes. A magnetic chicane is adopted to get the desired 300A peak current. After 5 months component installation, first photoelectrons were generated on 17 August 2016. In this paper, we give a summary of the commissioning experience and the beam parameters measurements. In addition, beam jitter sources are studied based on real machine performances.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB083

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB084

Beam Stability Modeling and Jitter Control for SXFEL Linac

1513

M. Zhang, R.B. Deng, D. Gu, Q. Gu, D. Huang, Z. Wang
SINAP, Shanghai, People's Republic of China

FEL operations foresee stringent requirements for the stability of the global linac output parameters and this requirement is particularly stringent for the successful operation of an externally seeded FEL. In order to understand the sensitivity of these parameters to jitters of various error sources along the SXFEL linac, studies have been performed based on analytical methods and tracking code simulations. Using the tolerance budget as guidance, beam jitter control techniques are discussed on the view of the beam dynamics.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB084

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB099

Status of MAX IV Linac Beam Commissioning and Performance

1547

S. Thorin, J. Andersson, M. Brandin, F. Curbis, L. Isaksson, M. Kotur, D. Kumbaro, F. Lindau, E. Mansten, D. Olsson, R. Svärd, S. Werin
MAX IV Laboratory, Lund University, Lund, Sweden
J. Björklund Svensson
Lund University, Division of Atomic Physics, Lund, Sweden

The MAX IV linac is used both for full energy injection into two storage rings at 3 GeV and 1.5 GeV, and as a high brightness driver for a Short Pulse Facility (SPF). The linac has also been designed to handle the high demands of an FEL injector. The linac is now routinely injecting into the two storage rings, and commissioning work is focused towards delivering high brightness pulses to the SPF. In this paper we present results from characterisation of the linac in ring injection mode, as well as results from measurements of key parameters for the SPF such as bunch length and emittance.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB099

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB130

Status of the LCLS-II Superconducting RF Linac

1630

A. Burrill
SLAC, Menlo Park, California, USA

The LCLS-II project requires the assembly and installation of 37 cryomodules in order to deliver a 4 GeV electron beam to the undulators to produce both soft and hard x-ray pulses at a repetition rate up to 1 MHz. All of the cryomodules will operate in continuous wave mode, with 35 operating at 1.3 GHz for acceleration and 2 operating at 3.9 GHz to linearize the longitudinal beam profile. The assembly and testing of the 1.3 GHz cryomodules is well underway and the 3.9 GHz cryomodule work is entering into the pre-cryomodule testing and component validation phase. Both of these efforts will be reported on in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB130

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB132

A Novel Dual-Mode Dual-Frequency Linac Design

1634

SUSPSIK123

use link to see paper's listing under its alternate paper code

M.H. Nasr, S.G. Tantawi
SLAC, Menlo Park, California, USA

In this paper we will present a new type of accelerator structure that operates simultaneously at two accelerating modes with two frequencies. The frequencies are not harmonically related, but rather have a common sub-harmonic. This design will use a recently developed parallel-feeding network that feeds every cavity cell independently using a distributed feeding network. This will overcome many of the practical complications of coupled cell structure. We will provide the theoretical background for our dual-mode design as well as present our optimized design that operates at C and X bands simultaneously and provides enhanced gradient and efficiency compared to single-mode designs.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB132

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB142

Tracking of Electrons Created at Wrong RF Phases in the RHIC Low Energy Cooler

1666

J. Kewisch, A.V. Fedotov, D. Kayran, S. Seletskiy
BNL, Upton, Long Island, New York, USA

Funding: Work supported by the US Department of Energy under contract No. DE-SC0012704.
The RHIC Low Energy Cooler will be based on a 400 keV DC electron gun with a photo-cathode and a 2.2 MeV SRF booster cavity. Electron that leave the cathode at the wrong time may be decelerated and turned around in the booster and return to the cathode with energies up to 1 MeV. On the way back these electron will encounter the defocussing EM fields up to nine following electron bunches. Such electrons may be created for various reasons: Cosmic rays, stray laser light including a catastrophic failure of the laser timing system or as secondaries of returning electrons. We present tracking results from the GPT program* and discuss the consequences for the machine protection system.
* www.pulsar.nl

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB142

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPAB143

Dependence of LEReC Beam Energy Spread on Photocathode Laser Modulation

1669

S. Seletskiy, M. Blaskiewicz, A.V. Fedotov, D. Kayran, J. Kewisch, M.G. Minty, B. Sheehy, Z. Zhao
BNL, Upton, Long Island, New York, USA
B. Sheehy
Sheehy Scientific Consulting, Wading River, New York, USA

Present requirements to the photocathode DC gun of the low energy RHIC electron cooling (LEReC) project is to produce 100 ps long bunch of electrons with 130 pC charge. The laser pulse of required length will be produced with the stacking of multiple few picosecond long sub-pulses. Depending on the choice of the laser sub-pulse length and on the relative delay between these sub-pulses one can obtain laser pulse with various longitudinal intensity modulations. The longitudinal modulation of laser intensity creates longitudinal modulation of electron bunch charge. Such modulation is known to cause the growth of e-beam uncorrelated energy spread in photoinjectors - the effect we would like to avoid. In this paper we estimate growth of e-beam energy spread due to its initial density modulation and set requirements to the maximum allowable depth of longitudinal modulation of photocathode laser intensity.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB143

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPIK033

Test and Commissioning Results of NSC KIPT 100 MeV/ 100 kW Electron Linear Accelerator, Subcritical Neutron Source Driver

1751

A.Y. Zelinsky, O.E. Andreev, V.P. Androsov, S.V. Bazarov, O. Bezditko, O.V. Bykhun, Y.L. Chi, A.N. Gordienko, V.A. Grevtsev, A. Gvozd, D.Y. He, X. He, V.E. Ivashchenko, A.A. Kalamayko, I.I. Karnaukhov, I.M. Karnaukhov, X.C. Kong, V.P. Lyashchenko, H.Z. Ma, M. Moisieienko, S. Pei, X.H. Peng, A.V. Reuzayev, I.M. Subotenko, D.V. Tarasov, V.I. Trotsenko, X. Wang
NSC/KIPT, Kharkov, Ukraine
Y.L. Chi, D.Y. He, X. He, X.C. Kong, H.Z. Ma, S. Pei, X.H. Peng, X. Wang
IHEP, Beijing, People's Republic of China
S. Shu
Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China

Neutron Source on the base of subcritical assembly has been constructed and is under commissioning in NSC KIPT, Kharkov, Ukraine. The source uses 100 MeV/ 100 kW electron linear accelerator as a driver. The accelerator was designed and manufactured in IHEP, Beijing, China. The accelerator has been assembled at NSC KIPT, all accelerator systems and components were and accelerator is under commissioning. Reports describes the status of the NSC KIPT 100 MeV/ 100 kW electron linear accelerator. The results of the first tests are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK033

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPIK104

Effects of Non-axisymmetric Solenoid Field on Beam Quality in Velocity Bunching

1958

Y.H. Wen
NTHU, Hsinchu, Taiwan
C.H. Chen, N.Y. Huang, W.K. Lau, A.P. Lee
NSRRC, Hsinchu, Taiwan

Space-charge effect is not negligible during the early stage of beam acceleration in a photoinjector rf linac that is operated for generation of short electron pulses by velocity bunching. A solenoid with iron shield can be used to provide the required axis-symmetric magnetic field to balance the radial space-charge force of the beam. However, the iron shield cannot be perfectly symmetric because openings are reserved for feeding water pipes and electrical cables to the coils. In addition, alignment errors of the solenoid may also spoil the symmetry of the focusing field. In this study, simulation is carried out to investigate how does the non-axisymmetric solenoid field of different origins influence beam properties, such as beam size, transverse emittance during the rf bunch compression.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK104

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)