IPAC2017 - Classification: 04 Hadron Accelerators / T12 Beam Injection/Extraction and Transport

Paper	Title	Page
MOPIK031	COSY Extraction Line Characterization and Modeling	567
	B. Lorentz, M. Bai, Y. Dutheil, R. Tölle, C. Weidemann FZJ, Jülich, Germany
	COSY is a versatile racetrack-type synchrotron accelerating protons and deuterons in a range of rigidity between 1 T m and 11 T m. Circulating beam can be slowly extracted on a third order resonance and channeled towards different users. New users of the COSY beam have presented new challenges with specific requests, most notably in term of beam shape. This in turn drove a strong interest to develop and improve characterization and modeling methods in the COSY extraction beam line. In this contribution we will present the different beam characterization methods used and their limitations. We will then discuss the modeling of the line and the importance of an accurate and reliable model of the extraction line. Some of the latest beam measurements are presented and compared to modeled results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK031
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK033	The Development of a New Low Field Septum Magnet System for Fast Extraction in Main Ring of J-PARC	573
	T. Shibata, K. Ishii, H. Matsumoto, N. Matsumoto, T. Sugimoto KEK, Ibaraki, Japan K.J. Kuanjun HUST, Wuhan, People's Republic of China
	The J-PARC Main Ring (MR) is being upgraded to improve its beam power to the design goal of 750 kW. One important way is to reduce the repetition period from 2.48 s to 1.3 s so that the beam power can be nearly doubled. We need to improve the septum magnets for fast extraction. We are improving the magnets and their power supplies. The present magnets which is conventional type have problem in durability of septum coil by its vibration, and large leakage field. The new magnets are eddy current type. The eddy current type does not have septum coil, but has a thin plate. We expect that there is no problem in durability, we can construct the thin septum plate, the leakage field can be reduced. The output of the present power supply are pattern current which of flat top is 10 ms width, the new one is short pulse which of one is 10 us. The short pulse consists of 1st and 3rd higher harmonic. We can expect that the flatness and reproducibility of flat top current can be improved. The calorific power can be also reduced. This paper will report the field measurement results with the eddy septum magnet systems.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK033
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK034	The New High Field Injection Septum Magnet System for Main Ring of J-PARC	576
	T. Shibata, K. Ishii, H. Matsumoto, N. Matsumoto, T. Sugimoto KEK, Ibaraki, Japan K. Fan HUST, Wuhan, People's Republic of China
	We are improving the Main Ring (MR) for beam power of 750 kw which is the first goal of J-PARC. The repetition period of the fast extraction must be short to 1.3 second from the current period of 2.48 second for the improvement of the beam power. We exchanged a injection septum magnet which are located at the injection line from RCS to MR and its power supply in summer of 2016. It was necessary to exchange, because the previous injection septum system can not be operated with 1.3 second repetition. The development of the new injection septum magnet and its power supply in which the maximum repetition are 1Hz and the order od the leakage field are 10^-4 of the gap field were completed in 2016. In this presentation, we will report the final results of its performance, e.g. the magnetic fields and stability of the output current and field, and the beam performance after installation in MR with the new injection magnet.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK034
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK035	New Injection Scheme of J-PARC Rapid Cycling Synchrotron	579
	K. Yamamoto, H. Harada, H. Hotchi, J. Kamiya, P.K. Saha, T. Takayanagi, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan N. Miki, O. Takeda Nippon Advanced Technology Co., Ltd., Tokai, Japan
	The 3-GeV Rapid Cycling Synchrotron (RCS) of Japan Proton Accelerator Research Complex (J-PARC) aims to deliver 1-MW proton beam to the neutron target and Main Ring synchrotron (MR). Present beam power of RCS is up to 500-kW and the higher radiation doses were concentrated in the injection area. These activations were caused by the interaction between the foil and the beam. To reduce the worker dose near the injection point, we have studied new design of the injection scheme to secure enough space for radiation shielding and bellows. In the new system, two of four injection pulse bump magnets are replaced and we are able to ensure the additional 500 mm space at the injection foil .
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK035
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK036	Study of the Magnetizing Relationship of the Kickers for CSNS	582
	M.Y. Huang, Y.W. An, S. Fu, N. Huang, W. Kang, Y.Q. Liu, L. Shen, L. Wang, S. Wang, Y.W. Wu, S.Y. Xu, J. Zhai, J. Zhang IHEP, Beijing, People's Republic of China
	Funding: Work supported by National Natural Science Foundation of China (11205185) The extraction system of CSNS mainly consists of two kinds of magnets: eight kickers and one lambertson magnet. In this paper, firstly, the magnetic test results of the eight kickers were introduced and then the filed uniformity and magnetizing relationship of the kickers were given. Secondly, during the beam commissioning in the future, in order to obtain more accurate magnetizing relationship, a new method to measure the magnetizing coefficients of the kickers by the real extraction beam was given and the data analysis would also be processed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK036
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK038	Initial Operation of the Low-Flux Proton Beamline at the KOMAC 100 MeV Linac	585
	S.P. Yun, C.R. Kim, D.I. Kim, H.S. Kim, H.-J. Kwon, S.G. Lee, Y.G. Song Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea
	Funding: This work was supported by the Ministry of Science, ICT and Future Planning of the Korean Government Korea multi-purpose Accelerator Complex (KOMAC) has been operating 20 MeV and 100 MeV proton beamlines to provide proton beams to users since 2013. The new beamline and target irradiation facility, which is proposed applicable to development of the detector and simulation of the space radiation, have being constructed for low-flux proton utilization at this year. The new beam lines have the 100 MeV of maximum beam energy and 10 nA of maximum beam current. The new beam line was designed to operate with maximum duty 8%, the flux density of proton beam can be reduced to the 1/10,000 by the graphite collimator. The extracted proton beam energy can be adjustable by the double wedge type energy degrader and also, the beam energy can be selected by dipole magnet. In addition to the two sets of the octupole magnets were prepared for uniform beam irradiation with the ± 5% uniformity. In this paper, the initial operation results of the constructed new beam line is be described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK038
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK039	Transport Channel of Secondary Ion Beam of Experimental Setup for Selective Laser Ionization With Gas Cell Gals	589
	N.Yu. Kazarinov, V. Bashevoy, G.G. Gulbekyan, I.A. Ivanenko, V.I. Kazacha, N.F. Osipov JINR, Dubna, Moscow Region, Russia S.G. Zemlyanoy JINR/FLNR, Moscow region, Russia
	GALS is the experimental setup intended for production and research of isobaric- and isotopically pure heavy neutron-rich nuclei. The beam line consists of two parts. The initial part is used for transport of the primary 136Xe ion beam with energy of 4.5-9.0 MeV/amu from the FLNR cyclotron U400M to the Pb target for the production of the studying ion beams. These beams have the following design parameters: the charge Z = +1, the mass A = 180-270 and the kinetic energy W = 40 keV. The second part placed after the target consists of SPIG (QPIG) system, the accelerating gap, the electrostatic Einzel lens, 90-degree spectrometric magnet (calculated value of the mass-resolution is equal to 1400) and the channel for the transportation of the ions from the focal plane of the magnet to a particle detector. The results of the simulation of particle dynamics and the basic parameters of the elements of the beam lines are presented in this report.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK039
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK041	Commissioning of the Stripping Foil Units for the Upgrade of the PSB H⁻ Injection System	595
	C. Bracco, S. Burger, V. Forte, B. Goddard, G. Guidoboni, L.O. Jorat, B. Mikulec, A. Navarro Fernandez, R. Noulibos, F. Roncarolo, P. Van Trappen, W.J.M. Weterings CERN, Geneva, Switzerland
	The PSB will be extensively upgraded during the next long shutdown of the CERN accelerator complex, to double the brightness of the stored beams. The existing multi-turn injection will be replaced by a charge exchange system designed for the 160 MeV hydrogen ions provided by Linac4. Part of the injection equipment has been temporarily installed along the Linac4-to-PSB transfer line and tested with beam. This allowed to gain experience with the system, test the related diagnostics and benchmark calculations with measurements. An additional permanent stripping foil test stand is also installed right after the Linac and will be used to characterise new foils for possible future applications. The main outcomes, issues and applied or planned mitigations are presented for both installations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK041
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK042	Beam-Based Kicker Waveform Measurements Using Long Bunches	599
	V. Forte, W. Bartmann, J.C.C.M. Borburgh, M.A. Fraser, L. Sermeus CERN, Geneva, Switzerland
	The increased bunch length demanded by the LHC Injectors Upgrade (LIU) project to mitigate emittance growth from space-charge on the PS injection plateau puts strong constraints on the rise-times of the recombination kickers in the transfer lines between the CERN Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS). A beam-based technique has been developed to validate the waveforms of the recombination kickers. In this paper high-resolution measurements are presented by extracting the intra-bunch deflection along bunches with lengths comparable to or longer than the rise-time of the kicker being probed. The methodology has been successfully applied to the three vertical recombination kickers named BT1. KFA10, BT4. KFA10 and BT2. KFA20, and benchmarked with direct measurements of the kicker field made using a magnetic field probe. This paper describes the beam-based technique, summarises the main characteristics of the measured waveforms, such as rise-time and flat-top ripple, and estimates their impact on beam brightness.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK042
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK043	Beam-Based Waveform Measurements of the CERN PS Injection Kicker	603
	V. Forte, W. Bartmann, J.C.C.M. Borburgh, L.M.C. Feliciano, A. Ferrero Colomo, M.A. Fraser, T. Kramer, L. Sermeus CERN, Geneva, Switzerland
	In the framework of the LHC Injectors Upgrade (LIU) project, a beam-based technique has been developed for measuring the waveform the CERN Proton Synchrotron (PS) horizontal injection kicker, named KFA45. The technique avoids the need for tedious magnetic measurements, especially when a spare magnet is presently unavailable and measuring the operational magnet with a magnetic field probe is complicated by integration reasons. In this paper, the technique and results of the waveform measurements are summarised. The results already provide additional information in terms of waveform characterisation for the validation of numerical simulations and are of great interest for the future LIU performance upgrade.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK043
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK044	The Use of a Passive Scatterer for SPS Slow Extraction Beam Loss Reduction	607
	B. Goddard, B. Balhan, J.C.C.M. Borburgh, M.A. Fraser, L.S. Stoel, F.M. Velotti CERN, Geneva, Switzerland
	A significant reduction in the fraction of protons lost on the SPS electrostatic septum ES during resonant slow extraction is highly desirable for present Fixed-Target beam operation, and will become mandatory for the proposed SHiP experiment, which is now being studied in the framework of CERN's Physics Beyond Colliders program. In this paper the possible use of a passive scattering device (diffuser) is investigated. The physics processes underlying the use of a diffuser are described, and the dependence on the diffuser geometry, material and location of the potential loss reduction on the electrostatic septum (ES) wires is investigated with a semi-analytical approach. Numerical simulations to quantify the expected performance gain for the optimum configuration are presented, and the results discussed in view of the feasibility of a potential realisation in the SPS.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK044
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK045	SPS Slow Extraction Losses and Activation: Challenges and Possibilities for Improvement	611
	M.A. Fraser, B. Balhan, H. Bartosik, C. Bertone, D. Björkman, J.C.C.M. Borburgh, N. Conan, K. Cornelis, R. Garcia Alia, L. Gatignon, B. Goddard, Y. Kadi, V. Kain, A. Mereghetti, F. Roncarolo, P.M. Schicho, J. Spanggaard, O. Stein, L.S. Stoel, F.M. Velotti, H. Vincke CERN, Geneva, Switzerland
	In 2015 the highest integrated number of protons in the history of the North Area was slow extracted from the CERN Super Proton Synchrotron (SPS) for the Fixed Target physics programme. At well over 1.10¹⁹ protons on target (POT), this represented the highest annual figure at SPS for almost two decades, since the West Area Neutrino Facility was operational some 20 years ago. The high intensity POT requests have continued into 2016-17 and look set to do so for the foreseeable future, especially in view of the proposed SPS Beam Dump Facility and experiments, e.g. SHiP, which are requesting up to 4·10¹⁹ POT per year. Without significant improvements, the attainable annual POT will be limited to well below the total the SPS machine could deliver, due to activation of accelerator equipment and associated personnel dose limitations. In this contribution, the issues arising from the recent high activation levels are discussed along with the steps taken to understand, manage and mitigate these issues. The research avenues being actively pursued to improve the slow extraction related beam loss for present operation and future requests are outlined, and their relative merits discussed. A. Golutvin et al., ‘‘A Facility to Search for Hidden Particles (SHiP) at the CERN SPS'', CERN, Geneva, Switzerland, Rep. CERN-SPSC-2015-016 (SPSC-P-350), Apr. 2015.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK045
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK046	Phase Space Folding Studies for Beam Loss Reduction During Resonant Slow Extraction at the CERN SPS	615
	L.S. Stoel, M. Benedikt, K. Cornelis, M.A. Fraser, B. Goddard, V. Kain, F.M. Velotti CERN, Geneva, Switzerland
	The requested number of protons slow-extracted from the CERN Super Proton Synchrotron (SPS) for Fixed Target (FT) physics is expected to continue increasing in the coming years, especially if the proposed SPS Beam Dump Facility is realised. Limits on the extracted intensity are already being considered to mitigate the dose to personnel during interventions required to maintain the extraction equipment, especially the electrostatic extraction septum. In addition to other on-going studies and technical developments, a reduction of the beam loss per extracted proton will play a crucial role in the future performance reach of the FT experimental programme at the SPS. In this paper a concept is investigated to reduce the fraction of beam impacting the extraction septum by folding the arm of the phase space separatrix. Beam dynamics simulations for the concept are presented and compared to the phase space acceptance of the extraction channel. The performance potential of the concept at SPS is evaluated and discussed alongside the necessary changes to the non-linear optical elements in the machine.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK046
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK047	Commissioning and Results of the Half-Sector Test Installation with 160 MeV H⁻ beam from Linac4	619
	B. Mikulec, D. Aguglia, J.C. Allica Santamaria, C. Baud, C. Bracco, S. Burger, G. Guidoboni, L.O. Jorat, C. Martin, A. Navarro Fernandez, R. Noulibos, F. Roncarolo, J.L. Sanchez Alvarez, J. Tan, T. Todorcevic, P. Van Trappen, W.J.M. Weterings, C. Zamantzas CERN, Geneva, Switzerland
	During the Long Shutdown 2 (LS2) at CERN in 2019/20, the Proton Synchrotron Booster (PSB) will undergo a profound upgrade in the framework of the LHC Injector Upgrade (LIU) project involving also the connection to the new Linac4 injector. The 160 MeV Linac4 H' injection entails a complete replacement of the PSB injection section, including a stripping foil system, injection chicane, an H⁰/H' dump and novel beam instrumentation. The equivalent of half of this new injection chicane was temporarily installed in the Linac4 transfer line to evaluate the performance of the equipment and prepare controls, interlocks and applications for the connection. Outcomes of this so-called Half-Sector Test (HST) are presented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK047
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK048	Experimental Results of Crystal-Assisted Slow Extraction at the SPS	623
	M.A. Fraser, S.S. Gilardoni, B. Goddard, V. Kain, D. Mirarchi, S. Montesano, S. Petrucci, S. Redaelli, R. Rossi, W. Scandale, L.S. Stoel, F.M. Velotti CERN, Geneva, Switzerland F.M. Addesa, G. Cavoto, F. Iacoangeli INFN-Roma, Roma, Italy F. Galluccio INFN-Napoli, Napoli, Italy F. Murtas INFN/LNF, Frascati (Roma), Italy
	The possibility of extracting highly energetic particles from the Super Proton Synchrotron (SPS) by means of silicon bent crystals has been explored since the 1990's. The channelling effect of a bent crystal can be used to strongly deflect primary protons and eject them from the synchrotron. Many studies and experiments have been carried out to investigate crystal channelling effects. The extraction of 120 and 270 GeV proton beams has already been demonstrated in the SPS with dedicated experiments located in the ring. Presently in the SPS, the UA9 experiment is performing studies to evaluate the possibility to use bent silicon crystals to steer particle beams in high energy accelerators. Recent studies on the feasibility of extraction from the SPS have been made using the UA9 infrastructure with a longer-term view of using crystals to help mitigate slow extraction induced activation of the SPS. In this paper, the possibility to eject particles into the extraction channel in LSS2 using the bent crystals already installed in the SPS is presented. Details of the concept, simulations and measurements carried out with beam are presented, before the outlook for the future is discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK048
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK049	SPS Slow Extracted Spill Quality During the 2016 Run	627
	V. Kain, J. Bauche, P. Catherine, K. Cornelis, M.A. Fraser, L. Gatignon, C.M. Genton, B. Goddard, K. Kahle, M. Magrans de Abril, O. Michels, L.S. Stoel, F.M. Velotti CERN, Geneva, Switzerland
	The flux of particles slow extracted with the 1/3 integer resonance from the Super Proton Synchrotron at CERN should ideally be constant over the length of the extraction plateau, for optimum use of the beam by the fixed target experiments. The extracted intensity is controlled in feed-forward correction of the horizontal tune via the main SPS quadrupoles. The Mains power supply noise at 50 Hz and harmonics is also corrected in feed-forward by small amplitude tune modulation at the respective frequencies with a dedicated additional quadrupole circuit. In 2016 the spill quality could be much improved with respect to the situation of the previous year with more performant algorithms. In this paper the improved tools are described and the characteristics of the SPS slow extracted spill in terms of macro structure and typical frequency content are shown. Other sources of perturbation were, however, also present in 2016 which frequently caused the spill quality to be much reduced. The different effects are discussed and possible or actual solutions detailed. Finally, the evolution of the spill quality during characteristic periods in the 2016 run is presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK049
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPIK103	Operation with Carbon Stripping Foils at ISIS	771
	H.V. Cavanagh, B. Jones STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The ISIS facility at the Rutherford Appleton Laboratory is a pulsed neutron and muon source for physical and life science research. Up to 3·10¹³ protons per pulse are accelerated to 800 MeV in the 50 Hz rapid cycling synchrotron that serves two spallation neutron targets. Charge exchange injection of 70 MeV H' ions into the synchrotron takes place over 130 turns. For over 30 years ISIS has used 40×120 mm aluminium oxide stripping foils, produced in-house [1]. Recently, foil preparation and installation processes have been simplified with the use of commercially available 40×60 mm carbon stripping foils. This paper summarises operational experiences with diamond-like-carbon (DLC) and graphene foils. Radiological analysis, atomic force microscope (AFM) imaging of foils and off-line irradiation with a 1.5 keV electron gun are also discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK103
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUOBA2	Commissioning of the MYRRHA Low Energy Beam Transport Line and Space Charge Compensation Experiments	1226
	F. Bouly, M.A. Baylac, D. Bondoux LPSC, Grenoble Cedex, France J. Belmans, D. Vandeplassche Studiecentrum voor Kernenergie - Centre d'Étude de l'énergie Nucléaire (SCK•CEN), Mol, Belgium N. Chauvin, F. Gérardin CEA/IRFU, Gif-sur-Yvette, France
	Funding: This work is supported by the European Atomic Energy Community's (EURATOM) H2020 Programme under grant agreement n°662186 (MYRTE project). The MYRRHA project aims at the construction of a new research reactor in Mol (Belgium) to demonstrate the nuclear waste transmutation feasibility with an Accelerator Driven System (ADS). In its subcritical configuration, the MYRRHA facility requires a proton beam with a maximum power of 2.4 MW (600 MeV - 4 mA). Such a continuous wave beam will be delivered by a superconducting linear accelerator (linac) which must fulfil very stringent reliability requirements to ensure the safe ADS operation with a high level of availability. The linac injector will be composed of: a proton source, a low energy beam transport line (LEBT), a 176 MHz RFQ and CH-DTL cavities. The LEBT prototype has been built and is presently installed and operated at LPSC Grenoble (France). An experimental program, to optimise the tuning of the line, the beam transport, and to study the space charge compensation mechanism, is in progress. We here review the main achievements of the LEBT commissioning. Experimental results will be presented and discussed, in particular the influence of the residual gas (type and pressure) on the beam dynamics.
	Slides TUOBA2 [3.929 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUOBA2
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

COSY Extraction Line Characterization and Modeling

567

B. Lorentz, M. Bai, Y. Dutheil, R. Tölle, C. Weidemann
FZJ, Jülich, Germany

COSY is a versatile racetrack-type synchrotron accelerating protons and deuterons in a range of rigidity between 1 T m and 11 T m. Circulating beam can be slowly extracted on a third order resonance and channeled towards different users. New users of the COSY beam have presented new challenges with specific requests, most notably in term of beam shape. This in turn drove a strong interest to develop and improve characterization and modeling methods in the COSY extraction beam line. In this contribution we will present the different beam characterization methods used and their limitations. We will then discuss the modeling of the line and the importance of an accurate and reliable model of the extraction line. Some of the latest beam measurements are presented and compared to modeled results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK031

Export •

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

MOPIK033

The Development of a New Low Field Septum Magnet System for Fast Extraction in Main Ring of J-PARC

573

T. Shibata, K. Ishii, H. Matsumoto, N. Matsumoto, T. Sugimoto
KEK, Ibaraki, Japan
K.J. Kuanjun
HUST, Wuhan, People's Republic of China

The J-PARC Main Ring (MR) is being upgraded to improve its beam power to the design goal of 750 kW. One important way is to reduce the repetition period from 2.48 s to 1.3 s so that the beam power can be nearly doubled. We need to improve the septum magnets for fast extraction. We are improving the magnets and their power supplies. The present magnets which is conventional type have problem in durability of septum coil by its vibration, and large leakage field. The new magnets are eddy current type. The eddy current type does not have septum coil, but has a thin plate. We expect that there is no problem in durability, we can construct the thin septum plate, the leakage field can be reduced. The output of the present power supply are pattern current which of flat top is 10 ms width, the new one is short pulse which of one is 10 us. The short pulse consists of 1st and 3rd higher harmonic. We can expect that the flatness and reproducibility of flat top current can be improved. The calorific power can be also reduced. This paper will report the field measurement results with the eddy septum magnet systems.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK033

Export •

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

MOPIK034

The New High Field Injection Septum Magnet System for Main Ring of J-PARC

576

T. Shibata, K. Ishii, H. Matsumoto, N. Matsumoto, T. Sugimoto
KEK, Ibaraki, Japan
K. Fan
HUST, Wuhan, People's Republic of China

We are improving the Main Ring (MR) for beam power of 750 kw which is the first goal of J-PARC. The repetition period of the fast extraction must be short to 1.3 second from the current period of 2.48 second for the improvement of the beam power. We exchanged a injection septum magnet which are located at the injection line from RCS to MR and its power supply in summer of 2016. It was necessary to exchange, because the previous injection septum system can not be operated with 1.3 second repetition. The development of the new injection septum magnet and its power supply in which the maximum repetition are 1Hz and the order od the leakage field are 10^-4 of the gap field were completed in 2016. In this presentation, we will report the final results of its performance, e.g. the magnetic fields and stability of the output current and field, and the beam performance after installation in MR with the new injection magnet.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK034

Export •

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

MOPIK035

New Injection Scheme of J-PARC Rapid Cycling Synchrotron

579

K. Yamamoto, H. Harada, H. Hotchi, J. Kamiya, P.K. Saha, T. Takayanagi, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
N. Miki, O. Takeda
Nippon Advanced Technology Co., Ltd., Tokai, Japan

The 3-GeV Rapid Cycling Synchrotron (RCS) of Japan Proton Accelerator Research Complex (J-PARC) aims to deliver 1-MW proton beam to the neutron target and Main Ring synchrotron (MR). Present beam power of RCS is up to 500-kW and the higher radiation doses were concentrated in the injection area. These activations were caused by the interaction between the foil and the beam. To reduce the worker dose near the injection point, we have studied new design of the injection scheme to secure enough space for radiation shielding and bellows. In the new system, two of four injection pulse bump magnets are replaced and we are able to ensure the additional 500 mm space at the injection foil .

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK035

Export •

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

MOPIK036

Study of the Magnetizing Relationship of the Kickers for CSNS

582

M.Y. Huang, Y.W. An, S. Fu, N. Huang, W. Kang, Y.Q. Liu, L. Shen, L. Wang, S. Wang, Y.W. Wu, S.Y. Xu, J. Zhai, J. Zhang
IHEP, Beijing, People's Republic of China

Funding: Work supported by National Natural Science Foundation of China (11205185)
The extraction system of CSNS mainly consists of two kinds of magnets: eight kickers and one lambertson magnet. In this paper, firstly, the magnetic test results of the eight kickers were introduced and then the filed uniformity and magnetizing relationship of the kickers were given. Secondly, during the beam commissioning in the future, in order to obtain more accurate magnetizing relationship, a new method to measure the magnetizing coefficients of the kickers by the real extraction beam was given and the data analysis would also be processed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK036

Export •

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

MOPIK038

Initial Operation of the Low-Flux Proton Beamline at the KOMAC 100 MeV Linac

585

S.P. Yun, C.R. Kim, D.I. Kim, H.S. Kim, H.-J. Kwon, S.G. Lee, Y.G. Song
Korea Atomic Energy Research Institute (KAERI), Gyeongbuk, Republic of Korea

Funding: This work was supported by the Ministry of Science, ICT and Future Planning of the Korean Government
Korea multi-purpose Accelerator Complex (KOMAC) has been operating 20 MeV and 100 MeV proton beamlines to provide proton beams to users since 2013. The new beamline and target irradiation facility, which is proposed applicable to development of the detector and simulation of the space radiation, have being constructed for low-flux proton utilization at this year. The new beam lines have the 100 MeV of maximum beam energy and 10 nA of maximum beam current. The new beam line was designed to operate with maximum duty 8%, the flux density of proton beam can be reduced to the 1/10,000 by the graphite collimator. The extracted proton beam energy can be adjustable by the double wedge type energy degrader and also, the beam energy can be selected by dipole magnet. In addition to the two sets of the octupole magnets were prepared for uniform beam irradiation with the ± 5% uniformity. In this paper, the initial operation results of the constructed new beam line is be described.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK038

Export •

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

MOPIK039

Transport Channel of Secondary Ion Beam of Experimental Setup for Selective Laser Ionization With Gas Cell Gals

589

N.Yu. Kazarinov, V. Bashevoy, G.G. Gulbekyan, I.A. Ivanenko, V.I. Kazacha, N.F. Osipov
JINR, Dubna, Moscow Region, Russia
S.G. Zemlyanoy
JINR/FLNR, Moscow region, Russia

GALS is the experimental setup intended for production and research of isobaric- and isotopically pure heavy neutron-rich nuclei. The beam line consists of two parts. The initial part is used for transport of the primary 136Xe ion beam with energy of 4.5-9.0 MeV/amu from the FLNR cyclotron U400M to the Pb target for the production of the studying ion beams. These beams have the following design parameters: the charge Z = +1, the mass A = 180-270 and the kinetic energy W = 40 keV. The second part placed after the target consists of SPIG (QPIG) system, the accelerating gap, the electrostatic Einzel lens, 90-degree spectrometric magnet (calculated value of the mass-resolution is equal to 1400) and the channel for the transportation of the ions from the focal plane of the magnet to a particle detector. The results of the simulation of particle dynamics and the basic parameters of the elements of the beam lines are presented in this report.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK039

Export •

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

MOPIK041

Commissioning of the Stripping Foil Units for the Upgrade of the PSB H⁻ Injection System

595

C. Bracco, S. Burger, V. Forte, B. Goddard, G. Guidoboni, L.O. Jorat, B. Mikulec, A. Navarro Fernandez, R. Noulibos, F. Roncarolo, P. Van Trappen, W.J.M. Weterings
CERN, Geneva, Switzerland

The PSB will be extensively upgraded during the next long shutdown of the CERN accelerator complex, to double the brightness of the stored beams. The existing multi-turn injection will be replaced by a charge exchange system designed for the 160 MeV hydrogen ions provided by Linac4. Part of the injection equipment has been temporarily installed along the Linac4-to-PSB transfer line and tested with beam. This allowed to gain experience with the system, test the related diagnostics and benchmark calculations with measurements. An additional permanent stripping foil test stand is also installed right after the Linac and will be used to characterise new foils for possible future applications. The main outcomes, issues and applied or planned mitigations are presented for both installations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK041

Export •

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

MOPIK042

Beam-Based Kicker Waveform Measurements Using Long Bunches

599

V. Forte, W. Bartmann, J.C.C.M. Borburgh, M.A. Fraser, L. Sermeus
CERN, Geneva, Switzerland

The increased bunch length demanded by the LHC Injectors Upgrade (LIU) project to mitigate emittance growth from space-charge on the PS injection plateau puts strong constraints on the rise-times of the recombination kickers in the transfer lines between the CERN Proton Synchrotron Booster (PSB) and the Proton Synchrotron (PS). A beam-based technique has been developed to validate the waveforms of the recombination kickers. In this paper high-resolution measurements are presented by extracting the intra-bunch deflection along bunches with lengths comparable to or longer than the rise-time of the kicker being probed. The methodology has been successfully applied to the three vertical recombination kickers named BT1. KFA10, BT4. KFA10 and BT2. KFA20, and benchmarked with direct measurements of the kicker field made using a magnetic field probe. This paper describes the beam-based technique, summarises the main characteristics of the measured waveforms, such as rise-time and flat-top ripple, and estimates their impact on beam brightness.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK042

Export •

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

MOPIK043

Beam-Based Waveform Measurements of the CERN PS Injection Kicker

603

V. Forte, W. Bartmann, J.C.C.M. Borburgh, L.M.C. Feliciano, A. Ferrero Colomo, M.A. Fraser, T. Kramer, L. Sermeus
CERN, Geneva, Switzerland

In the framework of the LHC Injectors Upgrade (LIU) project, a beam-based technique has been developed for measuring the waveform the CERN Proton Synchrotron (PS) horizontal injection kicker, named KFA45. The technique avoids the need for tedious magnetic measurements, especially when a spare magnet is presently unavailable and measuring the operational magnet with a magnetic field probe is complicated by integration reasons. In this paper, the technique and results of the waveform measurements are summarised. The results already provide additional information in terms of waveform characterisation for the validation of numerical simulations and are of great interest for the future LIU performance upgrade.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK043

Export •

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

MOPIK044

The Use of a Passive Scatterer for SPS Slow Extraction Beam Loss Reduction

607

B. Goddard, B. Balhan, J.C.C.M. Borburgh, M.A. Fraser, L.S. Stoel, F.M. Velotti
CERN, Geneva, Switzerland

A significant reduction in the fraction of protons lost on the SPS electrostatic septum ES during resonant slow extraction is highly desirable for present Fixed-Target beam operation, and will become mandatory for the proposed SHiP experiment, which is now being studied in the framework of CERN's Physics Beyond Colliders program. In this paper the possible use of a passive scattering device (diffuser) is investigated. The physics processes underlying the use of a diffuser are described, and the dependence on the diffuser geometry, material and location of the potential loss reduction on the electrostatic septum (ES) wires is investigated with a semi-analytical approach. Numerical simulations to quantify the expected performance gain for the optimum configuration are presented, and the results discussed in view of the feasibility of a potential realisation in the SPS.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK044

Export •

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

MOPIK045

SPS Slow Extraction Losses and Activation: Challenges and Possibilities for Improvement

611

M.A. Fraser, B. Balhan, H. Bartosik, C. Bertone, D. Björkman, J.C.C.M. Borburgh, N. Conan, K. Cornelis, R. Garcia Alia, L. Gatignon, B. Goddard, Y. Kadi, V. Kain, A. Mereghetti, F. Roncarolo, P.M. Schicho, J. Spanggaard, O. Stein, L.S. Stoel, F.M. Velotti, H. Vincke
CERN, Geneva, Switzerland

In 2015 the highest integrated number of protons in the history of the North Area was slow extracted from the CERN Super Proton Synchrotron (SPS) for the Fixed Target physics programme. At well over 1.10¹⁹ protons on target (POT), this represented the highest annual figure at SPS for almost two decades, since the West Area Neutrino Facility was operational some 20 years ago. The high intensity POT requests have continued into 2016-17 and look set to do so for the foreseeable future, especially in view of the proposed SPS Beam Dump Facility and experiments, e.g. SHiP*, which are requesting up to 4·10¹⁹ POT per year. Without significant improvements, the attainable annual POT will be limited to well below the total the SPS machine could deliver, due to activation of accelerator equipment and associated personnel dose limitations. In this contribution, the issues arising from the recent high activation levels are discussed along with the steps taken to understand, manage and mitigate these issues. The research avenues being actively pursued to improve the slow extraction related beam loss for present operation and future requests are outlined, and their relative merits discussed.
*A. Golutvin et al., ‘‘A Facility to Search for Hidden Particles (SHiP) at the CERN SPS'', CERN, Geneva, Switzerland, Rep. CERN-SPSC-2015-016 (SPSC-P-350), Apr. 2015.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK045

Export •

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

MOPIK046

Phase Space Folding Studies for Beam Loss Reduction During Resonant Slow Extraction at the CERN SPS

615

L.S. Stoel, M. Benedikt, K. Cornelis, M.A. Fraser, B. Goddard, V. Kain, F.M. Velotti
CERN, Geneva, Switzerland

The requested number of protons slow-extracted from the CERN Super Proton Synchrotron (SPS) for Fixed Target (FT) physics is expected to continue increasing in the coming years, especially if the proposed SPS Beam Dump Facility is realised. Limits on the extracted intensity are already being considered to mitigate the dose to personnel during interventions required to maintain the extraction equipment, especially the electrostatic extraction septum. In addition to other on-going studies and technical developments, a reduction of the beam loss per extracted proton will play a crucial role in the future performance reach of the FT experimental programme at the SPS. In this paper a concept is investigated to reduce the fraction of beam impacting the extraction septum by folding the arm of the phase space separatrix. Beam dynamics simulations for the concept are presented and compared to the phase space acceptance of the extraction channel. The performance potential of the concept at SPS is evaluated and discussed alongside the necessary changes to the non-linear optical elements in the machine.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK046

Export •

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

MOPIK047

Commissioning and Results of the Half-Sector Test Installation with 160 MeV H⁻ beam from Linac4

619

B. Mikulec, D. Aguglia, J.C. Allica Santamaria, C. Baud, C. Bracco, S. Burger, G. Guidoboni, L.O. Jorat, C. Martin, A. Navarro Fernandez, R. Noulibos, F. Roncarolo, J.L. Sanchez Alvarez, J. Tan, T. Todorcevic, P. Van Trappen, W.J.M. Weterings, C. Zamantzas
CERN, Geneva, Switzerland

During the Long Shutdown 2 (LS2) at CERN in 2019/20, the Proton Synchrotron Booster (PSB) will undergo a profound upgrade in the framework of the LHC Injector Upgrade (LIU) project involving also the connection to the new Linac4 injector. The 160 MeV Linac4 H' injection entails a complete replacement of the PSB injection section, including a stripping foil system, injection chicane, an H⁰/H' dump and novel beam instrumentation. The equivalent of half of this new injection chicane was temporarily installed in the Linac4 transfer line to evaluate the performance of the equipment and prepare controls, interlocks and applications for the connection. Outcomes of this so-called Half-Sector Test (HST) are presented in this paper.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK047

Export •

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

MOPIK048

Experimental Results of Crystal-Assisted Slow Extraction at the SPS

623

M.A. Fraser, S.S. Gilardoni, B. Goddard, V. Kain, D. Mirarchi, S. Montesano, S. Petrucci, S. Redaelli, R. Rossi, W. Scandale, L.S. Stoel, F.M. Velotti
CERN, Geneva, Switzerland
F.M. Addesa, G. Cavoto, F. Iacoangeli
INFN-Roma, Roma, Italy
F. Galluccio
INFN-Napoli, Napoli, Italy
F. Murtas
INFN/LNF, Frascati (Roma), Italy

The possibility of extracting highly energetic particles from the Super Proton Synchrotron (SPS) by means of silicon bent crystals has been explored since the 1990's. The channelling effect of a bent crystal can be used to strongly deflect primary protons and eject them from the synchrotron. Many studies and experiments have been carried out to investigate crystal channelling effects. The extraction of 120 and 270 GeV proton beams has already been demonstrated in the SPS with dedicated experiments located in the ring. Presently in the SPS, the UA9 experiment is performing studies to evaluate the possibility to use bent silicon crystals to steer particle beams in high energy accelerators. Recent studies on the feasibility of extraction from the SPS have been made using the UA9 infrastructure with a longer-term view of using crystals to help mitigate slow extraction induced activation of the SPS. In this paper, the possibility to eject particles into the extraction channel in LSS2 using the bent crystals already installed in the SPS is presented. Details of the concept, simulations and measurements carried out with beam are presented, before the outlook for the future is discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK048

Export •

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

MOPIK049

SPS Slow Extracted Spill Quality During the 2016 Run

627

V. Kain, J. Bauche, P. Catherine, K. Cornelis, M.A. Fraser, L. Gatignon, C.M. Genton, B. Goddard, K. Kahle, M. Magrans de Abril, O. Michels, L.S. Stoel, F.M. Velotti
CERN, Geneva, Switzerland

The flux of particles slow extracted with the 1/3 integer resonance from the Super Proton Synchrotron at CERN should ideally be constant over the length of the extraction plateau, for optimum use of the beam by the fixed target experiments. The extracted intensity is controlled in feed-forward correction of the horizontal tune via the main SPS quadrupoles. The Mains power supply noise at 50 Hz and harmonics is also corrected in feed-forward by small amplitude tune modulation at the respective frequencies with a dedicated additional quadrupole circuit. In 2016 the spill quality could be much improved with respect to the situation of the previous year with more performant algorithms. In this paper the improved tools are described and the characteristics of the SPS slow extracted spill in terms of macro structure and typical frequency content are shown. Other sources of perturbation were, however, also present in 2016 which frequently caused the spill quality to be much reduced. The different effects are discussed and possible or actual solutions detailed. Finally, the evolution of the spill quality during characteristic periods in the 2016 run is presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK049

Export •

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

MOPIK103

Operation with Carbon Stripping Foils at ISIS

771

H.V. Cavanagh, B. Jones
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The ISIS facility at the Rutherford Appleton Laboratory is a pulsed neutron and muon source for physical and life science research. Up to 3·10¹³ protons per pulse are accelerated to 800 MeV in the 50 Hz rapid cycling synchrotron that serves two spallation neutron targets. Charge exchange injection of 70 MeV H' ions into the synchrotron takes place over 130 turns. For over 30 years ISIS has used 40×120 mm aluminium oxide stripping foils, produced in-house [1]. Recently, foil preparation and installation processes have been simplified with the use of commercially available 40×60 mm carbon stripping foils. This paper summarises operational experiences with diamond-like-carbon (DLC) and graphene foils. Radiological analysis, atomic force microscope (AFM) imaging of foils and off-line irradiation with a 1.5 keV electron gun are also discussed.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK103

Export •

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

TUOBA2

Commissioning of the MYRRHA Low Energy Beam Transport Line and Space Charge Compensation Experiments

1226

F. Bouly, M.A. Baylac, D. Bondoux
LPSC, Grenoble Cedex, France
J. Belmans, D. Vandeplassche
Studiecentrum voor Kernenergie - Centre d'Étude de l'énergie Nucléaire (SCK•CEN), Mol, Belgium
N. Chauvin, F. Gérardin
CEA/IRFU, Gif-sur-Yvette, France

Funding: This work is supported by the European Atomic Energy Community's (EURATOM) H2020 Programme under grant agreement n°662186 (MYRTE project).
The MYRRHA project aims at the construction of a new research reactor in Mol (Belgium) to demonstrate the nuclear waste transmutation feasibility with an Accelerator Driven System (ADS). In its subcritical configuration, the MYRRHA facility requires a proton beam with a maximum power of 2.4 MW (600 MeV - 4 mA). Such a continuous wave beam will be delivered by a superconducting linear accelerator (linac) which must fulfil very stringent reliability requirements to ensure the safe ADS operation with a high level of availability. The linac injector will be composed of: a proton source, a low energy beam transport line (LEBT), a 176 MHz RFQ and CH-DTL cavities. The LEBT prototype has been built and is presently installed and operated at LPSC Grenoble (France). An experimental program, to optimise the tuning of the line, the beam transport, and to study the space charge compensation mechanism, is in progress. We here review the main achievements of the LEBT commissioning. Experimental results will be presented and discussed, in particular the influence of the residual gas (type and pressure) on the beam dynamics.

Slides TUOBA2 [3.929 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUOBA2

Export •

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