Keyword: rfq
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MOXBB101 Challenges facing High Power Proton Accelerators linac, proton, ion, injection 1
 
  • M.A. Plum
    ORNL, Oak Ridge, Tennessee, USA
  
  Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
This presentation will provide an overview of the challenges and experiences of high power proton accelerators such as SNS, J-PARC, etc. and what we have learned from experiences and how to mitigate beam losses. 		 
slides icon Slides MOXBB101 [6.734 MB]  
 
MOPEA032 Installation Status of Deuteron Injector of IFMIF Prototype Accelerator in Japan neutron, emittance, alignment, simulation 148
 
  • H. Shidara, J. Knaster
    IFMIF/EVEDA, Rokkasho, Japan
  • D. Bogard, N. Chauvin, P. Girardot, R. Gobin, F. Harrault, D. Loiseau, P.A.P. Nghiem, A. Roger, F. Senée
    CEA/DSM/IRFU, France
  • L. Semeraro
    F4E, Barcelona, Spain
  
  The International Fusion Materials Irradiation Facility (IFMIF) will generate a neutron irradiation field with the spectrum simulating the fusion D-T neutrons (14 MeV) to qualify suitable materials for fusion power plants. The IFMIF accelerator facility provides two CW / 40 MeV / 125 mA deuteron beams to the IFMIF Lithium target facility. In the Engineering Validation and Engineering Design Activities phase, the concept of IFMIF is validated with a single CW / 9 MeV / 125 mA deuteron accelerator prototype under construction in JAEA/Rokkasho. The injector part has been designed, constructed and successfully tested by CEA/Saclay. The ECR ion source produces a deuteron beam of 140 mA at 100 keV. In spring 2013, the injector will be delivered and re-installed on the Rokkasho site. This paper will focus on the detailed plan of the injector’s re-assembly as well as on the re-commissioning. Further possible improvements are discussed in order to achieve reliable operation.  
 
MOPEA039 Beam Commissioning and Neutron Radiography on a High Current Deuteron RFQ neutron, cavity, target, ECR 163
 
  • Y.R. Lu, J. Chen, J.E. Chen, S.L. Gao, Z.Y. Guo, F.J. Jia, G. Liu, S.X. Peng, H.T. Ren, W.L. Xia, X.Q. Yan, K. Zhu
    PKU, Beijing, People's Republic of China
  • S.Q. Liu, S. Wang, J. Zhao, B.Y. Zou
    State Key Laboratory of Nuclear Physics and Technology, Beijing, Haidian District, People's Republic of China
  
  Funding: Supported by NSFC 11079001 and Peking University
The high current deuteron RFQ has been developed and widely used in many projects, especially for accelerator based neutron source and its application. This paper reviews not only the recent developments in the world wide, also presents the beam dynamics, structure design ,RF full power test, beam commissioning of PKUNIFTY, which is consisted of a high current very compact ECR source, a 201.5MHz four-rod deuteron RFQ, thicker beryllium target and its moderating, collimation and neutron radiography system. RF and beam commissioning with duty cycle of 4% show the RFQ inter-vane voltage reaches 70kV at about 240kW, the delivered deuteron peak beam current is about 12mA at 290kW with the beam transmission of about 60%. The improvement of transmission is going on. The initial neutron radiography commissioning has been carried out. The results will promote the future development of small accelerator based neutron source. 		 
 
MOPFI033 Commissioning Results and Progress of a Helium Injector for Coupled RFQ and SFRFQ Project at Peking University ion, ion-source, emittance, cavity 357
 
  • J. Chen, J.E. Chen, S.L. Gao, Z.Y. Guo, Y.T. Luo, S.X. Peng, H.T. Ren, Z. Wang, Z.H. Wang, W.L. Xia, Y. Xu, A.L. Zhang, T. Zhang, J. Zhao
    PKU, Beijing, People's Republic of China
  
  At Peking University (PKU) a new helium injector for coupled radio frequency quadrupole(RFQ) and separated function radio frequency quadrupole(SFRFQ) within one cavity, so called as coupled RFQ & SFRFQ, was designed recently*. It will provide a 30keV 20mA He+ beam whose emittance is less than 0.15 π.mm.mrad for the accelerator. It is a combination of a 2.45GHz PKU PMECRIS (Permanent Magnet ECRIS) and a 1.16 m long LEBT. Within the 1.16 m LEBT, 2 solenoids, 2 steering magnets, a kicker, a space charge compensation section, a collimator, two vacuum valves, a Faraday cup and an ACCT are installed. The manufacture has been completed and the commissioning is on the way. In this paper we will address the commissioning results and its progress.
* Haitao Ren, et al., A Helium Injector for Coupled RFQ and SFRFQ Cavity Project at Peking University. Proc. LINAC’12, Paper TUPB034, Israel, 2012 		 
 
MOPME029 Multi-strip Current Monitor for Pulsed Laser Plasma Diagnostics plasma, ion, laser, target 538
 
  • Y. Fuwa, Y. Iwashita
    Kyoto ICR, Uji, Kyoto, Japan
  • M. Okamura
    BNL, Upton, Long Island, New York, USA
  
  A compact position-sensitive beam instrumentation devise is under development. The beam detection area of this devise is composed of multi-strip electrodes and scanned by multiplexers, which reduces the number of read-out lines and feed-through connectors. Combined with an electrostatic deflector and ToF information, this monitor can discriminate charge to mass ratios of particles. A prototype of this monitor is fabricated for measurement of ion distribution and charge state in laser induced plasma. This model has fifteen strip electrodes and the multiplexed signal and the clock signal are read out through two coaxial cables. Thus, only three cables are needed including a +5V power supply line. The test result will be presented.  
 
MOPWO001 Moment Method Beam Dynamics Code Development: Extended for Radio Frequency Quadrupole Simulations simulation, multipole, quadrupole, radio-frequency 879
 
  • T. Roggen, H. De Gersem, B. Masschaele
    KU Leuven, Kortrijk, Belgium
  • W. Ackermann, S. Franke, T. Weiland
    TEMF, TU Darmstadt, Darmstadt, Germany
  
  Funding: This research is funded by grant “KUL 3E100118” “Electromagnetic Field Simulation for Future Particle Accelerators”, project FP7-Euratom No. 269565 and the Belgian Nuclear Research Centre (SCK•CEN).
A Radio Frequency Quadrupole (RFQ) enables acceleration of a continuous low-velocity hadron beam, combining velocity independent electric focusing and adiabatic bunching, resulting in high-current compact bunches with nearly 100% capture and transmission efficiency. With virtually no post-construction tuning capabilities, an RFQ design phase requires all transient parameters (machining tolerances, thermo-mechanical deformation factors). This allows the determination of acceptable tolerances on input and output beam characteristics, of major importance in beam availability and beam trip prevention, and makes fast beam dynamics simulation codes incorporating RFQs indispensable. This article presents the implementation and validation of an RFQ beam line element into V-Code, a moment method beam dynamics simulation code. V-Code time integrates the Vlasov equation for an initial particle distribution represented by a discrete set of characteristic moments, accounting for all exerting internal and external forces. V-Code delivers highly accurate beam dynamics results with precision and efficiency advantages in terms of average or rms beam dimensions, projected emittances or total energy. 		 
 
TUOAB101 Installation and Commissioning of the 1.1 MW Deuteron Prototype Linac for IFMIF neutron, linac, proton, ion 1090
 
  • J. Knaster
    IFMIF/EVEDA, Rokkasho, Japan
  • P. Cara, A. Mosnier
    Fusion for Energy, Garching, Germany
  • S. Chel
    CEA/DSM/IRFU, France
  • J. Molla
    CIEMAT, Madrid, Spain
  • H. Suzuki
    Japan Atomic Energy Agency (JAEA), International Fusion Energy Research Center (IFERC), Rokkasho, Kamikita, Aomori, Japan
  
  IFMIF, the International Fusion Materials Irradiation Facility, will learn the degradation of the mechanical properties of purpose designed reduced activation ferritic-martensitic steels under bombardment of 14 MeV neutrons at 1018 n/m2s flux reaching values of 150 displacements per atom in the steel lattice. The understanding of the impact of Deuterium-Tritium fusion neutrons in next decade is essential to design and construct a fusion power plant; the next step after ITER. The 14 MeV neutrons are stripped from a liquid Li screen flowing at 15 m/s impacted by 2 parallel 125 mA deuteron beam at 40 MeV. IFMIF project, in its engineering validation phase, will operate in Rokkasho a 125 mA deuteron LINAC at 9 MeV that will validate the concept of IFMIF accelerator, LIPAc. The ion source will inject 140 mA deuterons at 100 KeV in a normal-conducting RFQ that will deliver the bunched beam at 5MeV to be accelerated up to 9 MeV thanks to 8 half-wave superconducting resonators. The installation and commissioning of LIPAc in Rokkasho (Japan) is sequential and the first stage is starting now; the strategy to overcome potential difficulties is detailed.  
slides icon Slides TUOAB101 [2.396 MB]  
 
TUOAB102 Project X Injector Experiment: Goals, Plan and Status kicker, ion, cryomodule, solenoid 1093
 
  • A.V. Shemyakin, S.D. Holmes, D.E. Johnson, M. Kaducak, R.D. Kephart, V.A. Lebedev, C.S. Mishra, S. Nagaitsev, N. Solyak, R.P. Stanek, V.P. Yakovlev
    Fermilab, Batavia, USA
  • D. Li
    LBNL, Berkeley, California, USA
  • P.N. Ostroumov
    ANL, Argonne, USA
  
  Funding: This work was supported by the U.S. DOE under Contract No.DE-AC02-07CH11359
A multi-MW proton facility, Project X, has been proposed and is currently under development at Fermilab. We are carrying out a program of research and development aimed at integrated systems testing of critical components comprising the front end of the Project X. This program is being undertaken as a key component of the larger Project X R&D program. The successful completion of this program will validate the concept for the Project X front end, thereby minimizing a primary technical risk element within Project X. Integrated systems testing, known as the Project X Injector Experiment (PXIE), will be accomplished with a new test facility under construction at Fermilab and will be completed over the period FY12- 17. PXIE will include an H− ion source, a CW 2.1-MeV RFQ and two superconductive RF (SRF) cryomodules providing up to 25 MeV energy gain at an average beam current of 1 mA (upgradable to 2 mA). Successful systems testing will also demonstrate the viability of novel front end technologies that are expected find applications beyond Project X. 		 
slides icon Slides TUOAB102 [1.615 MB]  
 
TUPFI003 The Accelerator Design of Muon g-2 Experiment at J-PARC target, proton, acceleration, beam-transport 1334
 
  • S. Artikova, F. Naito, M. Yoshida
    KEK, Ibaraki, Japan
  
  New muon g-2 experiment at J-PARC is aimed to improve the precise measurement of the muon g-2. In this experiment, the ultra-cold muons created in the muonium target region is reaccelerated to around 300MeV/c in momentum (210 MeV kinetic energy) to then be injected into the muon g-2 storage ring to measure the decay products depending on the muon spin. The linac has advantage over circular accelerators to shorten the reacceleration time in the limited life time of muon. The muon linac consists of the initial acceleration (to 0.01 of v/c), bunching section (0.01 to 0.08 of v/c), low beta section (0.08 to 0.3 of v/c), middle beta section (0.3 to 0.7 of v/c) and high beta section (0.7 to 0.94 of v/c). As a part of the design consideration of this linac, we mainly present the simulation result of initial acceleration and further acceleration of muons with RFQ. An electric field is used to extract the ultra-cold muons from the laser ionization region and RF field is used to create some bunches and to accelerate to higher energies.  
 
TUPWA004 Advanced Considerations for Designing Very High-intensity Linacs through Novel Methods of Beam Analysis, Optimization, Measurement & Characterisation emittance, linac, space-charge, extraction 1727
 
  • P.A.P. Nghiem, N. Chauvin, D. Uriot
    CEA/DSM/IRFU, France
  • W. Simeoni
    CEA/IRFU, Gif-sur-Yvette, France
  
  Research in fundamental physics, nuclear physics or advanced materials, requires linear accelerators as irradiation sources with higher and higher beam intensity. In such machines, not only high beam power but also high space charge are the major challenges. This double concern often induces conflicting issues, which should be overcome from the accelerator design stage. It progressively appears that the usual methods are no more sufficient. Even new concepts are to be invented. With mega-watt beams, losses and also micro-losses must be minimised while with very strong space charge, few room can be reserved for beam diagnostics. New strategies for design and tuning are to be carried out. The beam itself can no more be described only by its classical values like emittance and Twiss parameters. Core and halo parts should be instead precisely defined and kept under surveillance. The beam phase space distribution itself becomes determinant, which is very far from waterbag or gaussian distributions. This paper aims at proposing new considerations for very high-intensity linacs while recalling the usual ones, from designing and tuning methods to beam definitions and characterisations.  
 
TUPWA022 Beam Dynamics Design of a 325 MHz RFQ cavity, emittance, proton, simulation 1772
 
  • F.J. Jia, J.E. Chen, G. Liu, Y.R. Lu, X.Q. Yan
    PKU, Beijing, People's Republic of China
  • B.Q. Cui, J.H. Li, G.H. Wei
    CIAE, Beijing, People's Republic of China
  
  The beam dynamic design of a 325 MHz Radio Frequency Quadrupole (RFQ) is presented in this paper. This 4-vane RFQ will accelerate pulsed proton beam from 30 keV to 3 MeV with repetition frequency of 1 MHz. A 1 MHz chopper and a 5 MHz buncher are arranged in the Low-Energy-Beam-Transport (LEBT) to produce the injected beam. The beam length at the RFQ entrance is about 3 ns, and the energy-spread is about 10%. The code of PARMTEQM is used to simulate RFQ structure. The design should realize high transmission for very high intensity beam meanwhile low emittance growth and relatively short length should be kept.  
 
TUPWA023 Design of the Tuning System for the He+ Coupled RFQ-SFRFQ Cavity cavity, simulation, linac, impedance 1775
 
  • W.L. Xia, J.E. Chen, S.L. Gao, Z.Y. Guo, Y.R. Lu, S.X. Peng, Z. Wang, X.Q. Yan, J. Zhao, K. Zhu
    PKU, Beijing, People's Republic of China
  
  Funding: Supported by NSFC 10905003, 11079001, 91026012 Corresponding author: wangzhi@pku.edu.cn
The CRS (coupled RFQ-SFRFQ) cavity is a new type linac that couples traditional RFQ (radio frequency quadrupole) and SFRFQ (separated function RFQ) electrodes into a single cavity. The overall design of the CRS cavity has been completed and the linac is being manufactured currently. In this paper, we aimed to design a frequency tuning system for the CRS cavity, which will be used to explore the electromagnetic field distribution between RFQ and SFRFQ sections in the cavity. The frequency range, variation of Q value, power consumption and electric field distribution were investigated. Based on the beam dynamic program SFRFQDYNv1.0, we analysed the beam transmission properties of the cavity under the unbalanced electric field distribution. The optimized parameters of the tuning system were obtained. 		 
 
TUPWA054 PXIE End-to-end Simulations simulation, cryomodule, solenoid, emittance 1829
 
  • J.-F. Ostiguy, J.-P. Carneiro, V.A. Lebedev, A. Saini, N. Solyak
    Fermilab, Batavia, USA
  
  Funding: US DOE contract DE-AC02-76CH03000.
Construction of PXIE, (Project-X Injector Experiment) has recently begun. The goal is to validate the design of the injector and low energy acceleration front-end for a future Project-X. PXIE operates in CW mode and consists in an ion source, a magnetically focused LEBT, a 162.5 MHz RFQ, a MEBT equipped with high bandwidth traveling wave kickers, a cryomodule equipped with 162.5 MHz half-wave resonators and a single cryomodule based on 325 MHz spoke resonators. The arrangement is meant to be closely representative of a future Project-X front end, and will include a variety of diagnostics. In this contribution we present detailed end-to-end tracking simulations. In particular, we examine possible impact of the RFQ longitudinal distribution, neutralization effects in the LEBT as well as of various imperfections in the MEBT on losses in the first superconducting cavities. 		 
 
TUPWA059 End-to-end Beam Simulations for the C-ADS Injector II proton, linac, simulation, diagnostics 1838
 
  • X. Wu, E. Tanke, Q. Zhao
    FRIB, East Lansing, Michigan, USA
  • Y. He, H. Jia, Z.J. Wang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
  
  The Injector II for the proposed Chinese Accelerator Driven System (C-ADS) is designed to accelerate proton beam to ~ 10 MeV with beam current up to ~ 10 mA. The accelerator system will include a proton ECR ion source, a Low Energy Beam Transport System (LEBT), a room-temperature radio frequency quadrupole (RFQ), a Medium Energy Beam Transport System (MEBT), a Superconducting (SC) linac and a High Energy Beam Transport System (HEBT). Both RFQ and the SC linac will have a base frequency of 162.5 MHz. The accelerating cryomodules in the SC linac uses SC half-wave cavities for acceleration and SC solenoids with dipole correctors for transverse focusing and central orbit correction. End-to-end beam simulations starting with a realistic initial input beam from the ECR ion source were performed using DYNAC and IMPACT codes to evaluate the C-ADS Injector II accelerator system performance, code benchmarking with TRACK and explore system design options for future optimizations. The results of these beam dynamics studies will be presented in the paper.  
 
TUPWA067 Beam Emittance Growth Effects in High-intensity RFQ resonance, emittance, linac, space-charge 1859
 
  • Y.K. Batygin, R.W. Garnett, L. Rybarcyk
    LANL, Los Alamos, New Mexico, USA
  
  Beam dynamics in an RFQ are strongly affected by coupling between transverse and longitudinal particle oscillations. The adiabatic process of high-intensity bunched beam formation results in equipartitioning in the RFQ, which determines the longitudinal beam emittance. Avoiding parametric resonances is an important design criterion to prevent significant emittance growth of the beam. Manufacturing errors can result in beam emittance growth and reduction of beam transmission. This paper will present the results of a study where analytical and numerical evaluations were performed to determine the effect of the aforementioned factors on beam quality in a high-current RFQ.  
 
TUPWO037 Design Study of the Low Energy Beam Transport System at RISP solenoid, emittance, beam-transport, ion 1955
 
  • E.-S. Kim
    KNU, Deagu, Republic of Korea
  • J. Bahng
    Kyungpook National University, Daegu, Republic of Korea
  • J. Qiang
    LBNL, Berkeley, California, USA
  
  We present the design status of LEBT for the RISP that consists of two 90 degree dipoles, a multi-harmonic buncher, pair solenoids, electrostatic quadrupoles and a high voltage platform. After ECR-IS with an energy of 10 keV/u, heavy-ion beams are selected by achromatic bending systems and then be bunched in the LEBT. A multi-harmonic buncher is used to achieve a small longitudinal emittance in the RFQ. We show the results on the optics design by using the TRANSPORT code and the beam tracking of two-charge beams by using the code IMPACT. We present the results and issues on beam dynamics simulaitons in the designed LEBT system.  
 
TUPWO038 Start-to-end Simulations for Heavy-ion Accelerator of RISP linac, emittance, simulation, proton 1958
 
  • E.-S. Kim, S.W. Jang
    KNU, Deagu, Republic of Korea
  • J. Bahng, J.G. Hwang
    Kyungpook National University, Daegu, Republic of Korea
  • B. Choi, D. Jeon, H.J. Kim, H.J. Kim
    IBS, Daejeon, Republic of Korea
  
  RAON has been designed as a facility for rare isotope accelerator at Korea. The aceelerator consists of 28 GHz superconducting ion source, LEBT, RFQ, MEBT, superconducting linac and HEBT. The linac accelerates ion beams to 200 MeV/u with a beam power of 400 kW. Start-to-End simulations are performed from ECR-IS to HEBT and the detailed beam simulation results are presented. The beam dynamics issues are also discussed.  
 
TUPWO059 Reducing Emittance of a H− Beam in a Solenoid-based Low-energy Beam Transport through Numerical Modeling simulation, solenoid, emittance, electron 2000
 
  • J. von Stecher, D.L. Bruhwiler, B.T. Schwartz, S.A. Veitzer
    Tech-X, Boulder, Colorado, USA
  • B. Han, M.P. Stockli
    ORNL, Oak Ridge, Tennessee, USA
  
  Funding: This work is supported by the US DOE Office of Science, Office of Basic Energy Sciences, including grant No. DE-SC0000844
A solenoid-based low-energy beam transport (LEBT) subsystem is under development for the H− linac front end of the Spallation Neutron Source. The LEBT design includes MHz frequency chopping of the partially neutralized H− beam that can potentially lead to beam instabilities. We report results of numerical modeling using the parallel Vorpal framework for 3D electrostatic particle-in-cell (PIC) to simulate H− beam dynamics in the LEBT, over multiple chopping events. We detail how the addition of a positively biased potential barrier near the entrance of the chopper can improve LEBT performance by eliminating chopper-induced emittance increases over many chopping events.
DLB is now at University of Colorado, Boulder 		 
 
WEYB101 Power Upgrade of J-PARC Linac ion, linac, ion-source, cavity 2047
 
  • H. Oguri
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  
  A linac power upgrade program is now in progress after a successful recovery from the earthquake disaster. The power upgrade includes an ion source, an RFQ and a 400 MeV Annular-ring Coupled Structure (ACS) linac. We started a full-scale development of a cesium seeded RF-driven negative hydrogen ion source. The ion source extracted the beam of more than 60 mA with a duty factor of 2.5 %, which is satisfied with the requirement of the program. A new RFQ for 50 mA acceleration is under construction on the basis of a RFQ fabrication process, which was built as a backup for the present RFQ. Mass production of the ACS modules have almost completed. There is a plan to install these components and schedule the beam test in 2013. This presentation will cover the power upgrade status of the J-PARC linac.  
slides icon Slides WEYB101 [4.205 MB]  
 
WEOBB101 The KOMAC Accelerator Facility linac, DTL, proton, klystron 2052
 
  • Y.-S. Cho, J.-H. Jang, D.I. Kim, H.S. Kim, H.-J. Kwon, B.-S. Park, J.Y. Ryu, K.T. Seol, Y.-G. Song, S.P. Yun
    KAERI, Daejon, Republic of Korea
  
  Funding: This work was supported by the Ministry of Education, Science and Technology of the Korean Government.
The development of the Korea Multi-purpose Accelerator Complex (KOMAC) accelerator facility was finished and went into the operation period from 2013. The facility consists of an 100-MeV proton linac including a 50-keV ion source, a 3-MeV RFQ, and a 100-MeV DTL, and 20-MeV and 100-MeV beam lines. The linac and beam lines were developed by the Proton Engineering Frontier Project (PEFP), the first phase of KOMAC from 2002 to 2012. The goal of the beam commissioning is delivering 100-MeV 1-kW proton beams to a beam bump in a 100-MeV target room. After finishing the commissioning, the user beam service will start from spring 2013. The KOMAC user facility consists of 2 beam lines in the initial operation stage and it will be increased to 10 beam lines in future. The one beam line is for 20-MeV proton beams which are extracted after 20-MeV part of the DTL tanks. A medium energy beam transport (MEBT) is installed there for the 20-MeV beam extraction and the beam matching to the next DTL tank. The other beam line is for 100-MeV proton beams. This work summarized the status of the KOMAC accelerator and beam lines. 		 
slides icon Slides WEOBB101 [6.038 MB]  
 
WEPFI009 RF Measurement during CW Operation of an RFQ Prototype simulation, cavity, proton, linac 2720
 
  • M. Vossberg, H.C. Lenz, H. Podlech, A. Schempp
    IAP, Frankfurt am Main, Germany
  • A. Bechtold
    NTG Neue Technologien GmbH & Co KG, Gelnhausen, Germany
  
  A 17 MeV MHz proton linac is being developed as a front end of the driver accelerator for the MYRRHA facility in Mol. As a part of the MAX (MYRRHA Accelerator Experiment and Development) project a 4-rod Test-RFQ with a resonance frequency of 176 MHz has been designed and built for the MAX-Project. The RFQ has been modified to solve the cooling problem at cw-operation, the geometrical precision had to be improved as well as the rf-contacts. The developments led to a new layout and a sophisticated production procedure of the stems and the electrodes. Calculations show an improved Rp-value leading to power losses less than 30 kW/m, which is about 60 % of the power losses which could be achieved safely at cw-operation of the similar Saraf-RFQ. Thermal measurements and simulations with the single components has been completed. During cw-operation the temperature distribution will be measured and the rf-performance checked.  
 
WEPFI014 Present Status and Progresses of RFQ of IFMIF/EVEDA coupling, vacuum, linac, quadrupole 2729
 
  • R. Dima, A. Pepato, F. Scantamburlo, E. Udup
    INFN- Sez. di Padova, Padova, Italy
  • F. Grespan, A. Palmieri, C. Roncolato
    INFN/LNL, Legnaro (PD), Italy
  
  The RFQ of IFMIF/EVEDA is designed to accelerate a 125 mA D+ beam from 0.1 MeV to 5 MeV at a frequency of 175 MHz. The production of the modules 16, 17 and 18 necessary has been completed. In this paper the progress and improvements on the production of the modules, as well the development of the brazing procedure design will be described.  
 
WEPFI041 Design of the RF System for the Accelerator Complex of Rare Isotope Science Project cavity, LLRF, controls, rf-amplifier 2794
 
  • J. Han, O.R. Choi, J.-W. Kim
    IBS, Daejeon, Republic of Korea
  • C.K. Hwang
    KAERI, Daejon, Republic of Korea
  
  The rare isotope beam facility planned in Korea utilizes superconducting linear accelerators and a cyclotron to accelerate heavy-ion and proton beams, in which an RFQ in the injection line and superconducting cavities are the main rf components. The RF systems to power the cavities and to control the system at the low level have been designed so as to acquire high-quality beam with precise controls of rf amplitude and phase. The superconducting cavity is sensitive to various perturbations like mechanical vibration and Lorentz force detuning due to narrow bandwidth. We plan to use the rf amplifier system based on solid state device for superconducting cavities, and a tetrode tube for the final stage of RF amplifier of the RFQ accelerator. An LLRF system to control the amplitude and phase, which was built and tested on a quarter-wave resonator, will be modified to control a superconducting cavity. We plan to test the LLRF system in the superconducting rf facility abroad.  
 
WEPFI067 FETS RF System Design and Circulator Testing klystron, shielding, ion, insertion 2851
 
  • S.M.H. Alsari, J.K. Pozimski, P. Savage
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • M. Dudman, A.P. Letchford
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  
  The Front End Test Stand (FETS) is an experiment based at the Rutherford Appleton Laboratory (RAL) in the UK. In this experiment, the first stages necessary to produce a very high quality, chopped H− ion beam as required for the next generation of high power proton accelerators (HPPAs) are designed, built and tested. HPPAs with beam powers in the megawatt range have many possible applications including drivers for spallation neutron sources, neutrino factories, accelerator driven sub-critical systems, waste transmuters and tritium production facilities. RF system outline and design options of the waveguide and coaxial parts and shielding are presented and discussed in this paper. Experimental measurements of the system’s circulator will be presented as part of the system testing results.  
 
WEPFI070 Design of RFQ Coupler for PXIE Project simulation, cavity, coupling, ion 2854
 
  • S. Kazakov, T.N. Khabiboulline, V. Poloubotko, O. Pronitchev, V.P. Yakovlev
    Fermilab, Batavia, USA
  
  Design of new coupler for PXIE RFQ is reported. Two couplers are supposed to deliver ~ 100 kW total CW RF power to RFQ at 162.5 MHz. Coupler has a magnetic loop coupling with the RFQ. Nevertheless it allows to apply a HV bias to suppress a multipactor due to original design of the coupling loop. Results of RF, multipactor and thermal simulations are presented.  
 
WEPFI075 Design of the FRIB RFQ vacuum, linac, ion, dipole 2866
 
  • N.K. Bultman, G. Morgan, E. Pozdeyev, Y. Yamazaki, Q. Zhao
    FRIB, East Lansing, Michigan, USA
  • J. Stovall, L.M. Young
    TechSource, Santa Fe, New Mexico, USA
  
  Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
FRIB linac driver includes a front end and a SRF linac for all stable ion beams with energy more than 200 MeV/u, and beam power on target up to 400 kW. A 80.5 MHz FRQ at the front end accelerates heavy ion beams from 12 keV/u to 0.5 MeV/u, in CW mode. Design of the RFQ is introduced and several important technical issues are discussed in this paper. 		 
 
THPFI025 Design and Experimental Results of an Electro-static Pre-chopper for CSNS LEBT power-supply, radiation, simulation, cavity 3351
 
  • H.C. Liu, S. Fu, K.Y. Gong, H.F. Ouyang, J. Peng
    IHEP, Beijing, People's Republic of China
  
  The China Spallation Neutron Source (CSNS) front end incorporates a pre-chopper in the Low Energy Beam Transport line (LEBT) that will remove a 530ns section of beam at approximately 1MHz rate, which is the RF frequency of the ring at injection. It’s one of the most critical devices for properly controlling the injecting beam loss. Physical designing of the pre-chopper is carried out, and the RFQ itself was used as the beam dump of the chopper system. In order to examine the reliability of the pre-chopper design, the beam study of a similar chopper system was successfully performed. Results of physical design and experiments will be presented.  
 
THPME047 Progress of the RFQ Accelerator for PXIE emittance, simulation, beam-transport, ion 3618
 
  • D. Li, M.D. Hoff, A.R. Lambert, J.W. Staples, S.P. Virostek
    LBNL, Berkeley, California, USA
  • T.H. Luo
    UMiss, University, Mississippi, USA
  • S. Nagaitsev, G.V. Romanov, A.V. Shemyakin, R.P. Stanek, J. Steimel
    Fermilab, Batavia, USA
  
  Funding: This work is supported by the Office of Science, United States Department of Energy under DOE contract DE-AC02-05CH11231.
The proposed Project X Injector Experiment (PXIE) is currently under development at Fermilab. PXIE is an R&D test accelerator that will replicate the front-end portion of Project X. The PXIE accelerator complex consists of a H− ion source(s), low-energy beam transport (LEBT), 162.5 MHz normal conducting CW Radio-Frequency-Quadrupole (RFQ) accelerator, medium-energy beam transport (MEBT), broad-band beam chopper(s) and two superconducting cryomodules. In this paper, we will review and present recent progress of the PXIE RFQ, which will include an overview of the RFQ beam dynamics design, RF structure design, detailed thermal and mechanical analyses, fabrication test results and fabrication plan and schedule. 		 
 
THPWA041 Acceptance and Transmission Simulations of the FETS RFQ emittance, simulation, space-charge, solenoid 3720
 
  • S. Jolly, R.T.P. D'Arcy
    UCL, London, United Kingdom
  • A.P. Letchford
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • J.K. Pozimski
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • J.K. Pozimski
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  
  A 4m-long, 324MHz four-vane RFQ, consisting of four coupled sections, has been designed for the Front End Test Stand (FETS) at RAL in the UK. A novel design method, integrating the CAD and electromagnetic design of the RFQ with beam dynamics simulations, was used to optimise the design of the RFQ. With the design of the RFQ fixed, the focus has been on optimising the transmission of the RFQ at 3 MeV and matching the output of the FETS Low Energy Beam Transport (LEBT) to the RFQ acceptance. Extensive simulations have been carried out using General Particle Tracer (GPT) to map out the acceptance of the FETS RFQ for a 65 keV H− input beam. Particular attention has focussed on optimising the simulations to match the optimised output of the FETS Penning-type H− ion source. Results are presented of the transverse phase space limits on the RFQ input acceptance in both the zero current and full space charge regimes.  
 
THPWA042 Investigation of Space Charge Compensation at FETS ion, space-charge, ion-source, emittance 3723
 
  • J.K. Pozimski, S.M.H. Alsari, P. Savage
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • D.C. Faircloth, A.P. Letchford
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  
  In order to contribute to the development of high power proton accelerators in the MW range, to prepare the way for an ISIS upgrade and to contribute to the UK design effort on neutrino factories, a front end test stand (FETS) is being constructed at the Rutherford Appleton Laboratory (RAL) in the UK. The aim of the FETS is to demonstrate the production of a 60 mA, 2 ms, 50 pps chopped beam at 3 MeV with sufficient beam quality. The ion source and LEBT are operational with the RFQ under manufacture. As a more detailed knowledge is of interest also for other projects like ESS and LINAC4 the FETS LEBT was updated to perform a detailed experimental analysis of space charge compensation utilizing a pulsed decompensation electrode together with a residual gas ion energy spectrometer and a fast emittance measurement device. In the FETS LEBT a high degree of space charge compensation (~90%) and a rise time of space charge compensation around ~ 50 μs could be concluded from measurements . In this paper the results of the experimental work will be presented together with discussion of the findings in respect to beam transport.  
 
THPWA043 Production of the FETS RFQ vacuum, pick-up, alignment, simulation 3726
 
  • P. Savage, M. Aslaninejad, J.K. Pozimski
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • M. Dudman, D.S. Wilsher
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • A. Garbayo
    AVS, Eibar, Gipuzkoa, Spain
  • A.P. Letchford
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  
  The Front End Test Stand (FETS) project at RAL will use a 324 MHz 4-vane Radio Frequency Quadrupole (RFQ) to accelerate H− ions from 65keV to 3 MeV. This paper will report on the current status of the production of the FETS RFQ and will detail the manufacturing strategy used to produce the major and minor vanes. In addition the inspection results will be shown and the experiences from the assembly and alignment operations will be shared. Finally, the design of the bead-pull apparatus, end flanges, tuners and pick-ups required to measure the frequency and field-flatness of the assembled RFQ will be discussed.  
 
THPWO002 Progress of Construction and Installation of the SPIRAL2 Accelerator ion, linac, controls, vacuum 3755
 
  • R. Ferdinand, P. Bertrand, X. Hulin, M. Jacquemet, E. Petit
    GANIL, Caen, France
  
  Officially approved in May 2005, the SPIRAL2 project was launched in July 2005 at GANIL, with the active participation of French laboratories (CEA, CNRS) and international partners. This new facility is composed of a linear accelerator producing deuteron, proton and heavy ion beams in a wide range of energies and intensities, with two dedicated experimental areas in the fields of Neutron for Science (NFS) and very heavy and super heavy element production (S3). In a second step, the facility will also produce Rare elements serving a low energy RIB experimental hall, or post-accelerated by means of the existing cyclotron CIME. This paper presents the performances of the main accelerator components, and the installation process into the SPIRAL2 building.  
 
THPWO003 Final Design of the IFMIF Injector at CEA/Saclay extraction, simulation, diagnostics, solenoid 3758
 
  • R. Gobin, D. Bogard, N. Chauvin, O. Delferrière, P. Girardot, F. Harrault, J.L. Jannin, D. Loiseau, C. Marolles, P. Mattei, A. Roger, F. Senée, O. Tuske
    CEA/DSM/IRFU, France
  • H. Shidara
    IFMIF/EVEDA, Rokkasho, Japan
  
  The IFMIF accelerator dedicated to high neutron flux production for material studies is now entering in a new phase. For this irradiation tool, IRFU institute from CEA/Saclay is in charge of the design, construction and characterization of the Injector. The high intensity deuteron beam is produced by an ECR source located on a 100 kV platform. The 2 m long LEBT, based on 2 solenoids, is ended by a cone installed at the entrance of the RFQ. Specific diagnostics (cameras, Allison type emittance scanner, fiberscope) have been installed for the beam characterization. During the last weeks, after Injector conditioning, more than 100 mA of deuteron beams have been characterized after the RFQ entrance cone in pulsed and continuous mode*. The shipment of the Injector towards the Rokkasho site in Japan (where it will be reinstalled) is foreseen at the beginning of 2013. This paper will focus on the final design used during the beam characterization experiments at Saclay.
* N. Chauvin et al. this conference 		 
 
THPWO004 RF Tuning of the LINAC4 RFQ linac, coupling, quadrupole, dipole 3761
 
  • O. Piquet, Y. Le Noa, J. Novo
    CEA/DSM/IRFU, France
  • M. Desmons, A. France
    CEA/IRFU, Gif-sur-Yvette, France
  • C. Rossi
    CERN, Geneva, Switzerland
  
  The construction of Linac4, the new 160 MeV CERN H− injector, has started with the goal of improving the LHC injection chain with a new higher energy linac. The low energy front end of Linac4 is based on a 352 MHz, 3-m long Radiofrequency Quadrupole (RFQ) which accelerates the 70 mA, 45 keV H− beam from the ion source to the energy of 3 MeV. The RFQ, made of three modules, one meter each, is of the four-vane type and it has been designed in collaboration between CERN and CEA. Construction has started in 2009 and all the steps of machining and assembly have been done at CERN. The RFQ is equipped with 35 fixed tuners and one waveguide RF port located in the second module. This paper describes the procedure used to tune the accelerating field and the power coupler of the LINAC4 RFQ in order to achieve the nominal voltage profile within ±1% accuracy.  
 
THPWO005 Commissioning of the Spiral2 Deuteron Injector proton, emittance, space-charge, solenoid 3764
 
  • D. Uriot, O. Tuske
    CEA/DSM/IRFU, France
  • J.-L. Biarrotte
    IPN, Orsay, France
  
  The SPIRAL-2 superconducting linac driver, which aims at delivering 5 mA, 40 MeV deuterons and up to 1 mA, 14.5 A.MeV q/A=1/3 heavy ions, has now entered its construction phase in GANIL (Caen, France). The linac is composed of two injectors feeding one single RFQ, followed by a superconducting section based on 88 MHz independently-phased quarter-wave cavities with room temperature focusing elements. The protons/deuteron injector have been fully built and commissioned at CEA Saclay in 2012, before moving and final installation at GANIL in 2013. Beam emittances have been measured at different positions of the LEBT and especially at the RFQ injection point. The space-charge beam compensation has been also carefully studied. This paper describes all the results obtained during this commissioning.  
 
THPWO008 Status of the 70 MeV FAIR Proton Injector proton, linac, DTL, cavity 3773
 
  • G. Clemente, W.A. Barth, R. Bereznov, P. Forck, L. Groening, R. Hollinger, M. Kaiser, A. Krämer, F. Maimone, C. Mühle, J. Pfister, G. Schreiber, J. Trüller, W. Vinzenz, C. Will
    GSI, Darmstadt, Germany
  • R. M. Brodhage, B. Koubek, H. Podlech, U. Ratzinger, A. Schempp, R. Tiede
    IAP, Frankfurt am Main, Germany
  • N. Chauvin, O. Delferrière
    CEA/IRFU, Gif-sur-Yvette, France
  • B. Launé, J. Lesrel
    IPN, Orsay, France
  • C.S. Simon, O. Tuske
    CEA/DSM/IRFU, France
  
  Funding: BMBF
The FAIR project requires a dedicated proton injector for the creation of high intensity secondary antiproton beams. This machine will be the first high intensity linear accelerator based on CH-DTL. The status of the project, with particular emphasis on the construction of the first RF prototype is presented. 		 
 
THPWO009 Beam Dynamics Error and Loss Investigation of the FAIR Proton Injector linac, DTL, proton, quadrupole 3776
 
  • G. Clemente, W.A. Barth, P. Forck, L. Groening, R. Hollinger, M. Kaiser, J. Pfister, W. Vinzenz, S.G. Yaramyshev, C. Zhang
    GSI, Darmstadt, Germany
  • R. M. Brodhage, B. Koubek, H. Podlech, U. Ratzinger, A. Schempp, R. Tiede
    IAP, Frankfurt am Main, Germany
  • N. Chauvin, C.S. Simon, O. Tuske
    CEA/DSM/IRFU, France
  • O. Delferrière
    CEA/IRFU, Gif-sur-Yvette, France
  • B. Launé, J. Lesrel
    IPN, Orsay, France
  
  The FAIR Proton Linac is a 70mA, 70 MeV. 325 MHz linear accelerator based on CH cavities. The focusing scheme is provided by an asynchronous KONUS lattice period. Random misalignment and rotation errors of the quadrupoles, together with phase and RF settings of the power source plays a major role in beam losses. Those effects are investigated and the beam dynamics results, including several source of errors, are presented and discussed.  
 
THPWO014 Design Study of a High Frequency Proton Ladder RFQ cavity, proton, dipole, antiproton 3788
 
  • R. M. Brodhage, A. Almomani, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  
  For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. In the low energy section, between the Ion Source and the main linac an RFQ has to be designed. Accelerating protons from 95 keV to 3.0 MeV the RFQ will oscillate at 325 MHz. This particular high frequency for an RFQ creates difficulties which are challenging in developing this cavity. In order to define a satisfactory geometrical configuration for this resonator, both from the RF and the mechanical point of view, different designs have been examined and compared. Very promising results have been reached with an ladder type RFQ, especially concerning the dipole component of the accelerating fields, which is almost not noticeable. This paper will show 3D simulations of the general layout and a whole cavity demonstrating the power of a ladder type RFQ. It will outline a possible layout for the RFQ within the new FAIR proton injector.  
 
THPWO017 A Coupled RFQ-IH Cavity for the Neutron Source FRANZ DTL, linac, simulation, cavity 3797
 
  • M. Heilmann, C. Claessens, O. Meusel, D. Mäder, U. Ratzinger, A. Schempp, M. Schwarz
    IAP, Frankfurt am Main, Germany
  
  The Frankfurt neutron Source at the Stern-Gerlach-Zentrum (FRANZ) delivers neutrons in the energy range from 1 to 300 keV at high intensities. The neutrons are produced using the the 7Li(p,n)7Be reaction with 2 MeV protons. The linac accelerator cavities consists of a 4-rod-RFQ coupled with an 8 gap interdigital H-type drift tube section with a total cavity length of 2.3 m. It accelerates the 120 keV beam to 2.03 MeV at a frequency of 175 MHz. The combined cavity will be powered by one RF amplifier to reduce investment and operation costs. The inductive power coupler will be located at the RFQ part. The coupling into the IH – section is provided by direct inductive coupling within the cavity. The coupled RFQ-IH combination is investigated with CST-MWS-simulations and by an RF model. The linac combination has to match the resonance frequency, flatness along the RFQ and the voltage ratio between both cavity sections. Beam operation will be cw (a few mA) and pulsed 250 kHz, 50 ns (up to 50 mA and beyond). The thermal cavity losses are about 200 kW and the cooling is the challenging topic.  
 
THPWO018 Power Tests of the 325 MHz 4-ROD RFQ Prototype cavity, impedance, pick-up, simulation 3800
 
  • B. Koubek, H. Podlech, A. Schempp, J.S. Schmidt
    IAP, Frankfurt am Main, Germany
  
  For the FAIR project of GSI as part of the proton linac a 325 MHz RFQ with an output energy of 3 MeV is planned. Simulations that have lead to a prototype of a 4-Rod Radio Frequency Quadrupole (RFQ) have been done. The RF parameters have been verified with the prototype. Power tests of this 6 stem copper RFQ should now verify parameters like shunt impedance, electrode voltage and give answers of how much power the structure can sustain.  
 
THPWO020 Simulations on the Boundary Fields of 4-rod RFQ Electrodes simulation, cavity, quadrupole, shielding 3803
 
  • J.S. Schmidt, B. Koubek, A. Schempp
    IAP, Frankfurt am Main, Germany
  
  If the RF design of a 4-rod Radio Frequency Quadrupole (RFQ) is not performed carefully with respect to the boundary fields of its electrodes, it can produce errors compared to beam dynamic simulations. An additional field component can be induced on the beam axis, which influences the properties of the particle beam, like energy per nucleon for example, dramatically. Therefore, the influences of different geometric parameters of 4-rod RFQs on these fields have been studied in detail. The results of these simulations will be presented in this paper.  
 
THPWO022 Beam Dynamics Design, Simulation and Benchmarking for the C-ADS Injector-II RFQ simulation, emittance, linac, quadrupole 3809
 
  • C. Zhang
    GSI, Darmstadt, Germany
  • C. Xiao
    IAP, Frankfurt am Main, Germany
  
  The planned Chinese Accelerator Driven System (C-ADS) will use two 10 MeV, up to 10 mA, and CW (Continuous Wave) proton linacs in parallel as injectors. Two versions of the injectors with different resonant frequencies as well as different cavity configurations are under development. This paper will focus on the beam dynamics design, simulation and benchmarking performed for the 162.5 MHz, 2.1 MeV Injector-II RFQ (Radio-Frequency Quadrupole).  
 
THPWO023 The New RFQ as RIB Injector of the ALPI Linac linac, emittance, injection, ion 3812
 
  • M. Comunian, A. Palmieri, A. Pisent, C. Roncolato
    INFN/LNL, Legnaro (PD), Italy
  
  At the Legnaro National Laboratories it is operating a Super Conducting linac for nuclear studies named ALPI. A new project SPES is under study to provide neutron-rich rare nuclear beams (RIB) of final energies in the order of 10 MeV/A for nuclei in the A= 9-160 mass region. The radioactive ions will be produced with the ISOL technique using the proton induced fission on a Direct Target of UCx and subsequently reaccelerated using a new injector for the ALPI accelerator complex. In this paper the new RFQ injector and the transport line to ALPI will be describe.  
 
THPWO034 Fabrication of the RFQ III for the J-PARC Linac Current Upgrade linac, cavity, dipole, quadrupole 3839
 
  • T. Morishita, Y. Kondo, H. Oguri
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • K. Hasegawa
    JAEA, Ibaraki-ken, Japan
  • H. Kawamata, F. Naito, T. Sugimura
    KEK, Ibaraki, Japan
  
  The J-PARC accelerator comprises an injector linac, a 3-GeV Rapid-Cycling Synchrotron and a 50-GeV Main Ring. The J-PARC linac has been operating for users with the beam energy of 181 MeV. The energy (to 400MeV) and current (to 50mA) upgrade of the linac is scheduled for 1MW operation at RCS. For the current upgrade, the RFQ III, which is designed for 50mA beam acceleration, has been fabricated. The engineering design and the fabrication technologies are basically the same as the RFQ II in J-PARC linac. Some engineering methods are improved for the dimension accuracy, the reliability, and the period of fabrication. In the RFQ II fabrication, there was a leakage trouble at the electron-beam-welding spot by the thermal stress at the brazing only occasionally. Then, we changed to all-brazing design. Also, there was a vane deformation after the final machining. This was corrected by changing the method of fixation at the brazing. As a result, a dimension error was in a tolerable range. Currently, the fabrication is in a final process and the high-power test is scheduled at the second quarter of 2012.  
 
THPWO040 Progress of Injector-1 and Main Linac of Chinese ADS Proton Accelerator cavity, linac, proton, solenoid 3854
 
  • Y.L. Chi, J. Cao, J.P. Dai, H. Dong, L. Dong, T.M. Huang, X. Jing, S.P. Li, Z. Li, Z.Q. Li, Z.C. Liu, F. Long, Z. Ma, H.F. Ouyang, W.M. Pan, Q.L. Peng, P. Su, Y.F. Sui, J.Y. Tang, J.L. Wang, Q.B. Wang, Q. Ye, Z.S. Zhou
    IHEP, Beijing, People's Republic of China
  
  China ADS study program was Supported by the "Strategic Priority Research Program " of the Chinese Academy of Sciences at 2011, which aims to design and build an ADS demonstration facility with the capability of more than 1000 MW thermal power in about twenty years. The driver Linac is defined to be1.5 GeV in energy, 10mA in current and in CW operation mode. To meet the extremely high reliability and availability of ADS, the Linac is designed with much installed margin and fault tolerance. ADS accelerator is composed of two parallel 10MeV injectors and a main Linac. The superconducting acceleration structures are employed except the RFQs. This paper will present design of the China ADS accelerator and related key technology developments.  
 
THPWO041 The development of a high power input coupler for China ADS injector I RFQ coupling, cavity, vacuum, injection 3857
 
  • T.M. Huang, X. Chen, R. Guo, H.Y. Lin, Q. Ma, F. Meng, H.F. Ouyang, W.M. Pan, X.H. Peng, Z. Zhang, G.Y. Zhao
    IHEP, Beijing, People's Republic of China
  
  A 325 MHz RFQ is designed to accelerate a beam current of 15 mA in CW mode with injection energy of 35 keV and output energy of 3.2 MeV for China Accelerator Driven sub-critical System (ADS) injector I. Total RF power of 320 kW has to be delivered into the RFQ cavity. For reliable operation, four input couplers are adopted to share the driven power. A coaxial loop type input coupler is developed. The coupler features a Tristan type RF window, a doorknob to realize the transition from a half-height WR2300 waveguide to a coaxial line and a coaxial line with a coupling antenna loop. Two prototypes of the window and inner conductor assemblies have been fabricated and received high power test. The prototypes were tested up to 100 kW CW RF power in traveling wave mode. This paper will describe the design, fabrication and high power test of the coupler in details.  
 
THPWO042 Macroparticle Simulation Studies of a Beam-core Matching Experiment simulation, quadrupole, proton, emittance 3860
 
  • H. Jiang, P. Chen, S. Fu, T. Huang, F. Li, P. Li, H.C. Liu, C. Meng, M. Meng, Z.C. Mu, H.F. Ouyang, J. Peng, L.Y. Rong, B. Sun, J.M. Tian, B. Wang, S.C. Wang, W.Q. Xin, T.G. Xu, L. Zeng, F.X. Zhao
    IHEP, Beijing, People's Republic of China
  
  We compared the 3-D nonlinear macro- particle code IMPACT simulations with the measured beam-core profiles obtained by the wire-scanners in the beam-core matching experiment. Quadrupole scans were used to determinate the transverse properties of the RFQ output beam. The Gaussian distribution was chosen as the initial particle distribution, which is well fit with the measured beam-core profile. We matched the beam using the least-squares fitting procedure that adjusted the first four matching quadrupoles to produce equal rms beam size in the last six wire scanners. Simulations had been fairly successful in reproducing the core of the measured matched beam profiles.  
 
THPWO043 Progress on the Physics Design of the C-ADS Injector Scheme I linac, focusing, cavity, ion-source 3863
 
  • Z. Li, P. Cheng, H. Geng, C. Meng, H.F. Ouyang, B. Sun, J.Y. Tang, F. Yan, Z. Yang
    IHEP, Beijing, People's Republic of China
  
  Funding: Surported by China ADS Project
The China ADS (C-ADS) driver linac is composed of two parallel 10 MeV injectors and a main linac which boosts the beam further to 1.5 MeV. There are two design schemes for the injectors based on different working frequency and superconducting cavity structures and are under developing at the same time on IHEP and IMP. The Injector Scheme I, which is proposed by IHEP, works at 325 MHz, the same frequency of the main linac, and superconducting Spoke cavities with geometry beta of 0.12, the same type of cavity as the main linac too, are applied after the RFQ. In this paper, the latest progress on physics design will be presented. 		 
 
THPWO047 The LLRF Measurement and Analysis of the SSC-LINAC RFQ cavity, linac, LLRF, simulation 3875
 
  • G. Liu, J.E. Chen, S.L. Gao, Y.R. Lu, Z. Wang, X.Q. Yan, K. Zhu
    PKU, Beijing, People's Republic of China
  • X. Du, Y. He, G. Pan, Y.Q. Yang, X. Yin, Y.J. Yuan, Z.L. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
  
  Funding: Supported by NSFC(11079001)
The manufacturing process of the SSC-LINAC RFQ went to end and the LLRF measurement has been done. The frequency of the RFQ is 53.557 MHz without tuning, which is not far from the design value 53.667 MHz. The unflatness of the field along the beam axis is less than ±4%, which meets the simulation results. The dipole field is in the acceptable margin as well. The frequency will be adjusted by tuning plungers in operation. In this paper, the field distribution along the cavity has been measured and compared with the modulated electrodes simulation. The difference and its influences on the beam transmission have been analyzed. 		 
 
THPWO048 A CW High Charge State Heavy Ion RFQ for SSC-LINAC ion, heavy-ion, cavity, simulation 3878
 
  • Y.R. Lu, J.E. Chen, S.L. Gao, G. Liu, Z. Wang, X.Q. Yan, K. Zhu
    PKU, Beijing, People's Republic of China
  • Y. He, L.P. Sun, J.W. Xia, Y.Q. Yang, X. Yin, Y.J. Yuan, Z.L. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
  
  Funding: Supported by NSFC 11079001
To improve the super heavy ion beam injection efficiency and supply high current heavy ion beam for Separated Sector Cyclotron, A CW RFQ for heavy ion with high charge state has been designed and manufactured in the last two years. This RFQ will operate at 53.667MHz, will accelerate super heavy ions such as 238U34+ to 143keV/u. This paper will introduce the SSC-LINAC components, especially the RFQ beam dynamics, full length structure design, tuning and cooling method. Furthermore RF system and RF commissioning with full power for the RFQ power cavity will also be presented. 		 
 
THPWO049 Preliminary Beam Dynamics and Structure Design of One 50mA/CW RFQ with Ramped Inter-vane Voltage simulation, radio-frequency, linac, quadrupole 3881
 
  • L. Du, X. Guan, C.-X. Tang, Q.Z. Xing
    TUB, Beijing, People's Republic of China
  
  Funding: Work supported by National Natural Scienccontracte Foundation of China (Major Research Plan Grant No. 91126003 and Project 11175096).
The beam dynamics and structure design of a ramped-voltage CW RFQ (Radio Frequency Quadrupole) accelerator for a NSFC (National Natural Science Foundation of China) Project at Tsinghua University is presented in this paper. The ramped-voltage RFQ, in which the inter-vane voltage increases from the low-energy end to the high-energy end, is compact and efficient. The RFQ, with the operating frequency of 325 MHz, will capture a 50 mA/CW, 50 keV proton beam from the RF source and accelerate it to 3 MeV, an energy suitable for chopping and injecting the beam in a conventional Drift Tube Linac. After optimization, the total length is as short as 2.9 m and the transmission rate is above 97%. The design of RFQ structure including the undercuts will also be shown. 		 
 
THPWO050 High Power Test and Beam Commissioning of he CPHS RFQ Accelerator klystron, vacuum, proton, ECR 3884
 
  • Q.Z. Xing, C. Cheng, L. Du, Q. Du, T. Du, C. Jiang, H.T. Lu, J. Ni, Q. Qiang, C.-X. Tang, X.W. Wang, Y.G. Yang, H.Y. Zhang, S.X. Zheng
    TUB, Beijing, People's Republic of China
  • J.H. Billen
    Self Employment, Private address, USA
  • W.Q. Guan, Y. He, J. Li
    NUCTECH, Beijing, People's Republic of China
  • X. Guan
    Tsinghua University, Beijing, People's Republic of China
  • J. Stovall
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  • L.M. Young
    LMY Technology, USA
  
  Funding: Work supported by the “985 Project” of the Ministry of Education of China, National Natural Science Foundation of China (Major Research Plan Grant No. 91126003 and 11175096).
We present, in this paper, the high power test result and the beam commissioning status of a Radio Frequency Quadrupole (RFQ) accelerator for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. The 3-meter-long RFQ is designed to deliver 3 MeV protons to the downstream High Energy Beam Transport (HEBT) with the peak current of 50 mA, pulse length of 0.5 ms and beam duty factor of 2.5%. The RFQ has been designed, manufactured, and installed at Tsinghua University. High-vacuum test of the RFQ has been carried out carefully and the cooling system has been mounted. At the beginning of 2013, the high power RF test has been performed and the first 3 MeV proton beam is obtained. 		 
 
THPWO051 Status of CPHS Project neutron, proton, linac, target 3887
 
  • S.X. Zheng, H.B. Chen, C. Cheng, Q. Du, T. Du, X. Guan, X.Y. Jia, C. Jiang, H.T. Lu, C.-X. Tang, D. Wang, D. Wang, X.W. Wang, H.Y. Zhang, Z. Zhang
    TUB, Beijing, People's Republic of China
  • W.Q. Guan, Y. He, J. Li, D.-S. zhang
    NUCTECH, Beijing, People's Republic of China
  
  CPHS (Compact Pulsed Hadron Source) project was initiated in Tsinghua University at 2009. It consists of a 13 MeV proton Linac (RFQ+DTL), a neutron target station and some neutron stations. The construction of 3 MeV Linac (RFQ only) and target station will be finished at the end of 2012. And initial commissioning will be started at the early of year 2013. The progress and results of early commissioning will be presented at this paper. Then we will report the next plan also.  
 
THPWO059 Beam Dynamics Design of the Main Accelerating Section with KONUS in the CSR-LINAC Proposal linac, emittance, DTL, heavy-ion 3895
 
  • X.H. Zhang, H. Du, J.W. Xia, X. Yin, Y.J. Yuan
    IMP, Lanzhou, People's Republic of China
  
  The CSR-LINAC as the injector of the Cooling Storage Ring (CSR) has been proposed in Heavy Ion Research Facility in Lanzhou (HIRFL). The injection linac mainly consists of two Linacs, the Radio Frequency Quadrupole linac (RFQ) and the Drift Tube Linac (DTL). The KONUS (Kombinierte Null Grad Struktur) concept has been introduced to the drift tube linac section. In this paper, the re-matching of the main accelerating section will be finished in the 3.7MeV/u scheme and the new beam dynamics design updating to 7MeV/u will be shown. Through the beam re-matching, the relative emittance growth has been suppressed greatly along the linac. The KONUS structure is also adopted in the beam dynamics design that update from 3.7MeV/u to 7MeV/u and the good beam quality and transmission is shown.  
 
THPWO066 Beam Commissioning of KOMAC Linac DTL, linac, proton, simulation 3909
 
  • J.-H. Jang, Y.-S. Cho, D.I. Kim, H.S. Kim, H.-J. Kwon, B.-S. Park, J.Y. Ryu, K.T. Seol, Y.-G. Song, S.P. Yun
    KAERI, Daejon, Republic of Korea
  
  Funding: This work was supported by the Ministry of Education, Science and Technology of the Korean Government.
The proton engineering frontier project (PEFP), which is the first phase of Korea multi-purpose accelerator complex (KOMAC), developed a 100-MeV proton linac which consists of a 50 keV injector, a 3-MeV radio frequency quadrupole (RFQ) and a 100-MeV drift tube linac (DTL). The installation of the linac was finished in 2012. The goal of the beam commissioning in spring 2013 is accelerating 100-MeV proton beams with the beam power of 1 kW to the beam dump which is located downstream of the linac. This work summarized the beam commissioning result for the linac. 		 
 
THPWO069 Development of the NICA Injection Facility ion, ion-source, linac, injection 3915
 
  • A.V. Butenko, E.D. Donets, E.E. Donets, V.V. Fimushkin, A. Govorov, A.D. Kovalenko, K.A. Levterov, I.N. Meshkov, V. Monchinsky, A.Yu. Ramsdorf, A.O. Sidorin, G.V. Trubnikov
    JINR, Dubna, Moscow Region, Russia
  • H. Hoeltermann, H. Podlech, U. Ratzinger, A. Schempp
    BEVATECH OHG, Offenbach/Main, Germany
  • A. Kolomiets, G. Kropachev, T. Kulevoy
    ITEP, Moscow, Russia
  • S.M. Polozov
    MEPhI, Moscow, Russia
  
  The new accelerator complex Nuclotron-based Ion Collider fAcility (NICA) is assumed to operate using two injectors: the Alvarez-type linac LU-20 as injector for light ions, polarized protons and deuterons and a new linac HILac for heavy ions. The main features of ion sources and both linacs are presented. Upgrade for pre-accelerator of LU-20 is described.  
 
THPWO074 Technical Design of the ESS Facility linac, DTL, target, proton 3927
 
  • S. Peggs
    ESS, Lund, Sweden
  
  The 5 MW European Spallation Source is entering a construction phase for the entire facility. This paper surveys the unique features, challenges and open issues that exist, from ion source to target, and from moderator to instruments. It is consistent with the ESS-wide Technical Design Report, published in April 2013.
The paper is presented on behalf of the ESS consortium, and all the contributors to the ESS TDR. 		 
 
THPWO075 Beam Loss Limits in High Power Proton Linear Accelerators proton, DTL, radiation, linac 3930
 
  • L. Tchelidze
    ESS, Lund, Sweden
  • J. Stovall
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  
  High power hadron linear accelerators are designed based on 1 W/m loss limit criteria. The loss limit originates from the hands-on-maintenance allowance of the accelerators and limits average dose rate level to less than 0.1 - 1 mSv/hr at 30 cm from a machine after 100 days of continuous operation and 4 hours of down time. However, machine activation and thus beam loss limit depends on incident particle energy and 1 W/m is only a good approximation for energies 100-200 MeV and higher (in H-/H+ accelerators). At lower energies though, one could allow much higher than 1 W/m without excess activation. A careful analysis of energy dependent loss limits was performed for proton linacs as part of the study for the European Spallation Source (ESS) linac, for energy ranges 5 MeV – 2.5 GeV. ESS linac is to be built in Lund, Sweden and will deliver 5 MW proton beam to the target. MARS code was used for calculations and beam loss limits were derived as a function of energy.  
 
THPWO076 Design Study for 10 MHz Beam Frequency of Post-accelerated RIBs at HIE-ISOLDE emittance, bunching, linac, solenoid 3933
 
  • M.A. Fraser, R. Calaga, I.-B. Magdau
    CERN, Geneva, Switzerland
  
  An increased bunch spacing of approximately 100 ns is requested by several research groups targeting experimental physics at HIE-ISOLDE. A design study testing the feasibility of retrofitting the existing 101.28 MHz REX (Radioactive ion beam EXperiment) RFQ with a sub-harmonic external pre-buncher at the ISOLDE radioactive nuclear beam facility has been carried out as a means of decreasing the beam frequency by a factor of 10. The proposed scheme for the 10 MHz bunch repetition frequency is presented and its performance assessed with beam dynamics simulations. The opportunity to reduce the longitudinal emittance formed in the RFQ is discussed along with the options for chopping the satellite bunches populated in the bunching process.  
 
THPWO082 Commissioning of the Linac4 RFQ at the 3 MeV Test Stand linac, diagnostics, solenoid, emittance 3951
 
  • C. Rossi, L. Arnaudon, G. Bellodi, J.C. Broere, O. Brunner, A.M. Lombardi, J. Marques Balula, P. Martinez Yanez, J. Noirjean, C. Pasquino, U. Raich, F. Roncarolo, M. Vretenar
    CERN, Geneva, Switzerland
  • M. Desmons, A. France, O. Piquet
    CEA/IRFU, Gif-sur-Yvette, France
  
  Linac4, the future 160MeV H− injector to the CERN Proton Synchrotron Booster, is presently under construction at CERN as a first step of the planned upgrade of the LHC injectors. The low energy section of LINAC4, consisting of an ion source, a 352.2 MHz Radio Frequency Quadrupole (RFQ) and a chopper line is being commissioned in a dedicated test stand before installation in its final position in the tunnel. The RFQ is designed to accelerate a 45 keV, 70 mA, H− beam to 3 MeV, with an efficiency of 95% while preserving the transverse emittance. The RFQ, a four-vane structure 3 m in length, has been designed in collaboration with CEA/IRFU and it has been built at the CERN workshop. The precise fabrication has allowed to achieve a field flatness of 1%. The completion of the accelerating structure in September 2012 was followed by a complete series of bead-pull measurements and by high-power conditioning to the nominal power of 0.39 MW corresponding to a voltage of 78 kV across the 3 meters. Measurements with beam are foreseen during the first half of 2013. This paper reports the results of the low-power and high power RF commissioning as well as the status of beam measurements.  
 
THPWO086 Status of the RAL Front End Test Stand ion, ion-source, beam-transport, status 3963
 
  • A.P. Letchford, M.A. Clarke-Gayther, D.C. Faircloth, S.R. Lawrie
    STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
  • S.M.H. Alsari, M. Aslaninejad, J.K. Pozimski, P. Savage
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
  • J.J. Back
    University of Warwick, Coventry, United Kingdom
  • G.E. Boorman, A. Bosco, S.M. Gibson
    Royal Holloway, University of London, Surrey, United Kingdom
  • R.T.P. D'Arcy, S. Jolly
    UCL, London, United Kingdom
  • C. Gabor, D.C. Plostinar
    STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
  • J.K. Pozimski
    STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
  
  The Front End Test Stand (FETS) under construction at RAL is a demonstrator for the front end systems of a future high power proton linac. Possible applications include a linac upgrade for the ISIS spallation neutron source, new future neutron sources, accelerator driven sub-critical systems, a neutrino factory etc. Designed to deliver a 60mA H-minus beam at 3MeV with a 10% duty factor, FETS consists of a high brightness ion source, magnetic low energy beam transport (LEBT), 4-vane 324MHz radio frequency quadrupole, medium energy beam transport (MEBT) containing a high speed beam chopper and non-destructive photo-detachment diagnostics. This paper describes the current status of the project and future plans.  
 
THPWO091 Staging Scenarios for Project-X linac, emittance, lattice, acceleration 3972
 
  • N. Solyak, J.-P. Carneiro, V.A. Lebedev, S. Nagaitsev, J.-F. Ostiguy, A. Saini, A. Vivoli, V.P. Yakovlev
    Fermilab, Batavia, USA
  
  Funding: US DOE under contract DE-AC02-76CH03000.
Project-X is a high intensity proton source in development at Fermilab. At its heart is a linac based on superconducting technology comprising two distinct sections. The first one operates in CW mode and delivers beam with a flexible time structure to simultaneous experimental programs at 1 and 3 GeV. The second one operates in pulsed mode and accelerates a modest fraction (5%) of the beam from 3 GeV to 8 GeV for accumulation in the existing Main Injector complex. In an era of constrained budgets, construction in stages -with each stage capable of supporting worthy scientific programs - may be advantageous. Requirements for each program, coupled to the physical constraints imposed by the Fermilab site have led to a few possible scenarios, which are discussed in this contribution. In particular, we examine the implications of introducing bends in the linac at 1 and 3 GeV in terms of overall performance, flexibility and cost. 		 
 
THPWO094 Electromagnetic and Multi-particle Beam Dynamics Modeling of 4-Rod RFQs simulation, vacuum, quadrupole, cavity 3978
 
  • S.S. Kurennoy, R.W. Garnett, L. Rybarcyk
    LANL, Los Alamos, New Mexico, USA
  
  Detailed 3D modeling of the recently commissioned FNAL 4-rod RFQ was performed with the CST Studio Suite. The RFQ model is based on the CAD files used for its fabrication, which are imported in CST Studio. The electromagnetic (EM) analysis was done with MicroWave Studio (MWS) and the beam dynamics modeled with Particle Studio (PS) using the MWS-calculated fields. Realistic matched input CW beam distributions, generated externally with up to 10K particles per RF period and up to 70 RF periods long, are injected in the RFQ for PS simulations. The EM analysis reveals some interesting features of the RFQ fields; their origin and influence on the beam parameters is studied. In particular, the end-gap longitudinal field, which is usually not taken into account when an RFQ is designed with standard codes, can change the output beam energy. Our CST modeling results helped explain and successfully resolve some problems encountered in the FNAL RFQ commissioning. We plan to use a similar approach to evaluate a new 4-rod RFQ that will become a part of an upgraded front end of the LANSCE linac.