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proton

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MO101 J-PARC Project neutron, kaon, linac, hadron 1
 
  • S. Nagamiya
    KEK, Ibaraki
 
 

About ten years ago (2001) a new accelerator project to provide high-intensity proton beams proceeded into its construction phase. This project is called the J-PARC (Japan Proton Accelerator Research Complex), and it was completed about a year ago in 2009. The construction was performed under a cooperation of two institutions, KEK and JAEA. The goal of the accelerator power is 1 MW proton beams at 3 GeV, with 400 MeV Linac injector, and 0.75 MW beams at 50 GeV. Three experimental facilities are presently available: 1) the Materials and Life Experimental Facility where pulsed neutrons and muon beams from 3 GeV are produced and utilized, 2) the Hadron Experimental Facility where kaon beams are produced, with a slow extraction mode from the 50 GeV (currently, 30 GeV is used), and 3) the Neutrino Experimental Facility with fast extraction mode from the 50 GeV ring. I would like to review the current status of the accelerators and experimental facilities, in particular, under the emphasis of what are actually going on in regard experimental programs. I also would like to mention a future scope of the J-PARC.

 
MOP039 First Beams Produced by the Spiral-2 Injectors ion, emittance, ECR, heavy-ion 139
 
  • J.-L. Biarrotte
    IPN, Orsay
  • P. Bertrand
    GANIL, Caen
  • C. Peaucelle
    IN2P3 IPNL, Villeurbanne
  • T. Thuillier
    LPSC, Grenoble
  • O. Tuske, D. Uriot
    CEA, Gif-sur-Yvette
 
 

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 first stages of the injectors have been fully built and are now operational. They have been partly commissioned with beam in Grenoble and Saclay in 2010. This paper describes the results obtained so far in this context.

 
MOP055 A CW SRF Linac to Drive Subcritical Nuclear Reactors linac, SRF, cavity, neutron 178
 
  • M. Popovic
    Fermilab, Batavia
  • C.M. Ankenbrandt, R.P. Johnson
    Muons, Inc, Batavia
 
 

In the last 20 years, superconducting RF (SRF) cavities have been developed to the point that a CW SRF linac is the best candidate driver for subcritical reactors. We discuss how one appropriately designed linac can be used for an accelerator-driven subcritical (ADS) nuclear power station to produce more than 5 GW electrical power in an inherently safe region below criticality. Such a station will generate no greenhouse gases, produce minimal nuclear waste and no byproducts that are useful to rogue nations or terrorists, incinerate waste from conventional nuclear reactors, and efficiently use abundant thorium fuel that does not need enrichment. We describe the Linac parameters that can enable this vision of an almost inexhaustible source of power and we discuss how the corresponding reactor technology can be matched to these parameters.

 
MOP061 Exploring the Energy/Beam Current Parameter Space for the Isotope Production Facility (IPF) at LANSCE target, isotope-production, kicker, linac 193
 
  • M.S. Gulley, H. T. Bach, L.J. Bitteker, K.D. John, F.M. Nortier, C. Pillai, F.O. Valdez
    LANL, Los Alamos, New Mexico
  • A. Seifter
    EPO, Rijswijk
 
 

IPF has recently investigated isotope production with proton beams at energies other than the 100-MeV currently available to the IPF beam line. To maximize the yield of a particular isotope, it is necessary to measure the production rate and cross section versus proton beam energy. Studies were conducted at 800 MeV and 197 MeV to determine the cross section of terbium-159. Also, the ability to irradiate targets at different proton beam energies opens up the possibility of producing other radioisotopes. A proof-of-principle test was conducted to develop a 40-MeV tune in the 100-MeV beam line. Another parameter explored was the beam current, which was raised from the normal limit of 250 uA up to 356 uA via both power and repetition rate increase. This proof-of-principle test demonstrated the capability of the IPF beam line for high current operation with potential for higher isotope yields. For the full production mode, system upgrades will need to be in place to operate at high current and high duty factor. These activities are expected to provide the data needed for the development of a new and unique isotope production capability complementing the existing 100-MeV IPF facility.

 
MOP062 Linac followed by an Electron Cooler to Provide a Short Bunch Proton Beam linac, electron, extraction, beam-cooling 196
 
  • A. Noda, H. Souda, H. Tongu
    Kyoto ICR, Uji, Kyoto
  • T. Fujimoto, S.I. Iwata, S. Shibuya
    AEC, Chiba
  • K. Noda, T. Shirai
    NIRS, Chiba-shi
 
 

Proton beams accelerated by an RFQ and a DTL with resonant frequency of 433 MHz,are electron cooled after injection into a storage ring, S-LSR and fast extracted to a beam irradiation target. Short pulse duration around 3.5 ns is expected for the 7 MeV proton beam with the intensity of 1.4 x 108 [1]. This beam is to be utilized for irradiation of biological cells in order to investigate Radio Biological Effectiveness of proton beam with a very high peak intensity for the purpose of quantitative verification of the recent report on the DNA double strand breaking with the use of short-pulse laser-produced proton beam [2]


[1] T. Fujimoto et al., Nucl. Instr. and Meth. Phys. Res. A588 (2008) 330-335.
[2] A. Yogo et al., Appl. Phys. Lett. 94 (2009) 181502.

 
MOP071 The Hot Prototype of the PI-Mode Structure for Linac4 cavity, linac, coupling, vacuum 220
 
  • F. Gerigk, P. Bourquin, A. Dallocchio, G. Favre, J.-M. Geisser, L. Gentini, J.-M. Giguet, S.J. Mathot, M. Polini, D. Pugnat, B. Riffaud, S. Sgobba, T. Tardy, P. Ugena Tirado, M. Vretenar, R. Wegner
    CERN, Geneva
 
 

The PIMS cavities for Linac4 are made of 7 coupled cells operating in pi-mode at 352 MHz frequency. The mechanical concept is derived from the 5-cell cavities used in the LEP machine, whereas cell length and coupling are adapted for proton acceleration in the range from 50 to 160 MeV. Linac4 will be the first machine to employ this type of cavities for low-beta protons. During the first years of operation the PIMS will be used at low duty cycle as part of the consolidated LHC proton injector complex. It is designed, however, to operate eventually in a high duty cycle (10%) proton injector, which could be used as proton front-end for neutrino or RIB applications. To prepare for the series construction of the 12 PIMS units the first cavity (102 MeV beam energy) has been designed and constructed at CERN, to be used as a hot prototype for RF tests and as a pre-series mechanical unit. In this paper we report on some of the design features, the construction experience, and first measurements.

 
MOP099 Status of the Design of 650 MHz Elliptical Cavities for Project X cavity, linac, beam-losses, coupling 289
 
  • S. Barbanotti, M.H. Foley, I.G. Gonin, J. Grimm, T.N. Khabiboulline, L. Ristori, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia
 
 

Project X is a proposed high-intensity proton accelerator complex that could provide beam to create a high-intensity neutrino beam, feed protons to kaon- and muon-based precision experiments, and for other applications still under investigation. The present configuration of the proton accelerator foresees a section with 650 MHz beta = 0.6 and beta = 0.9 elliptical cavities. Prototypes of single-cell 650 MHz cavities and five-cell beta = 0.9 650 MHz cavities are being designed and fabricated at Fermilab in the R&D process for Project X. This paper summarizes the design status of the beta = 0.6 and beta = 0.9 single-cell prototype cavities, and also addresses the design effort focused on the five-cell beta = 0.9 cavities.

 
MOP100 Bunch Compressor for Intense Proton Beams space-charge, dipole, target, linac 292
 
  • L.P. Chau, M. Droba, O. Meusel, D. Noll, U. Ratzinger, C. Wiesner
    IAP, Frankfurt am Main
 
 

The Frankfurt Neutron source FRANZ is under construction*. The ARMADILLO bunch compressor** as a part of it is composed of a 5MHz electric kicker, a magnetic dipole chicane and rf-rebunching cavities. The design phase of the bunch compressor has reached the final stage. A 175MHz 2MeV proton linac forms 100ns long beam pulses consisting of nineμbunches with 150mA. Deflected by the 5MHz kicker theμbunches are guided on different paths to arrive within 1ns at a n-production target. Due to high space charge forces rebuncher cavities are included***. The peak current at the target is expected to be in the range of 10A in a 1ns proton pulse, which is equivalent to a longitudinal pulse compression ratio of 45. A new code specific for complex magnetic multi aperture system and for high current applications has been developed. Hardware designs according to the beam dynamics results are in progress. Improved 3D magnetic and electric fields will be applied in the future beam dynamics studies including high space charge forces. The preliminary designs and the beam dynamics studies will be presented in this contribution.


* O. Meusel, et al.: LINAC06, Knoxville, Tennessee USA, 2006, pp. 159-161.
** L. P. Chau, et al.: EPAC08, Genoa, Italy, 2008, pp. 3578-3580.
*** D. Noll, another contribution at this conference.

 
MOP101 Rebuncher Cavities for the FRANZ Bunch Compressor cavity, impedance, neutron, linac 295
 
  • D. Noll, L.P. Chau, M. Droba, O. Meusel, H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main
 
 

The Frankfurt Neutron Source (FRANZ) currently under construction at IAP (Goethe University of Frankfurt) is designed to produce short neutron pulses at high intensity and repetition rates up to 250 kHz [*]. To achieve a bunch length of one nanosecond despite the high space charge forces, a bunch compressor of the Mobley type [**] using four dipole magnets and two rebunchers has been developed [***] to merge 9 linac bunches into the final focus. The first rebuncher cavity, a λ/4 resonator operating at 87.5 MHz, has to feature nine beam paths due to the multi-trajectory system. Additionally the gaps have to be displaced relatively to each other in a way that all bunches arrive at the correct rf phase. The second rebunching cavity will provide final focusing as well as an energy variation of ±0.2 MeV in front of the target and will be operating at 175 MHz. This paper presents the design of these novel cavities as well as the simulated beam dynamic properties.


* Meusel et al., LINAC 2006
** Mobley, Phys. Rev. 88(2), 360-361 (1951)
*** Chau et al, LINAC 2010

 
TUP019 Proton Linac for ADS Application in China linac, cavity, rfq, ECR 437
 
  • S. Fu, S.X. Fang, J.Q. Wang
    IHEP Beijing, Beijing
  • X. Guan
    CIAE, Beijing
 
 

In the next two decades, China will be in period of fast development of nuclear power to meet the energy demands of the rapid economy growth and to cut down the CO2 release. Accelerator Driven System is recognized as the best option for nuclear radioactive waste transmutation. ADS long-term development roadmap has been proposed. Based on the ADS basic study in the last decade, a samll-scale ADS facility is going to be built to do experimental research on ADS system. In this paper, we will first review the previous R&D activity on ADS linac research in China, and then introduce the design of the linac in the small-scale ADS facility.

 
TUP020 Accelerator Reference Design for the MYRRHA European ADS Demonstrator cavity, linac, target, cryomodule 440
 
  • J.-L. Biarrotte
    IPN, Orsay
  • H. Klein
    IAP, Frankfurt am Main
  • A.C. Mueller
    IN2P3, Paris
  • P. Pierini
    INFN/LASA, Segrate (MI)
  • D. Vandeplassche
    SCK-CEN, Mol
 
 

The goal of the MYRRHA project is to demonstrate the technical feasibility of transmutation in an Accelerator Driven System (ADS) by building a new flexible irradiation complex in Mol (Belgium). The MYRRHA facility requires a 600 MeV accelerator delivering a maximum proton flux of 4 mA CW operation. Such a machine belongs to the category of the high-power proton accelerators, with an additional requirement for exceptional reliability: because of the induced thermal stress to the subcritical core, the number of unwanted beam interruptions should be minimized down to the level of about 10 per 3-month operation cycle, a specification that is far above usual proton accelerators performance. This paper describes the reference solution adopted for such a machine, based on a so-called 'fault-tolerant' linear superconducting accelerator, and presents the status of the associated R&D.

 
TUP022 A Linac for Compact Pulsed Hadron Source Project AT Tsinghua University Beijing rfq, DTL, target, neutron 1
 
  • X. Guan
    TUB, Beijing
 
 

This paper will be generally reported that a new project of the Compact Pulsed Hadron Source (CPHS) led by the Department of Engineering Physics of Tsinghua University in Beijing, China. CPHS consists of a proton linac (13MeV, 16kW, Operating frequency 325MHz, peak current 50 mA, 0.5 ms pulse width at 50 Hz), a neutron target station (a Be target, moderators and reflector), and a small-angle neutron scattering instrument, a neutron imaging/radiology station, and a proton irradiation station. The linac accelerator is the main part of this project, which including a ECR ion source. LEBT section, a RFQ accelerator, a DTL linac and a HEBT An An experimental platform for further proton applications and more neutron beam lines will be added at a later stage. Currently, fabrication of the accelerator components has begun while the neutron target station, beam lines and instruments are under design study. The initial phase of the CPHS construction is scheduled to complete in the end of 2012.

 
TUP023 CH-Cavity Development for the 17 MeV EUROTRANS Injector cavity, DTL, linac, simulation 446
 
  • F.D. Dziuba, M. Busch, H. Klein, H. Podlech, U. Ratzinger, C. Zhang
    IAP, Frankfurt am Main
 
 

Recent international cw operated high-current applications with ambitious requirements regarding beam power and quality ask for new linear accelerator developments. In this context the CH-structure (Crossbar-H-mode) has been developed at the Institute for Applied Physics (IAP) of Frankfurt University. It is a multi-cell drift tube cavity for the low and medium energy range operated in the H21-mode and can be used for superconducting as well as for room temperature applications. Because of the large energy gain per cavity, which leads to high real estate gradients, the CH-cavity is an excellent candidate for the efficient acceleration in high power proton and ion accelerators with fixed velocity profiles. One possible application for this kind of cavity is the EUROpean research programme for the TRANSmutation (EUROTRANS) of high level nuclear waste in an accelerator driven system (ADS), which requires an efficient high-current cw-linac (600 MeV, 4 mA, protons, 352 MHz). The paper describes the status of the CH-cavity development and the actual beam dynamics results for the reference design of the 17 MeV EUROTRANS injector.

 
TUP025 Operational Status and Life Extension Plans for the Los Alamos Neutron Science Center (LANSCE) neutron, target, scattering, isotope-production 452
 
  • K.W. Jones, J.L. Erickson, R.W. Garnett, M.S. Gulley
    LANL, Los Alamos, New Mexico
 
 

The Los Alamos Neutron Science Center (LANSCE) accelerator and beam delivery complex generates the proton beams that serve three neutron production sources, a proton radiography facility and a medical and research isotope production facility. The recent operating history of the facility, including both achievements and challenges, will be reviewed. Plans for performance improvement will be discussed, together with the underlying drivers for the ongoing LANSCE Life Extension project. The details of this latter project will also be discussed.

 
TUP027 A New Medium Energy Beam Transport Line for the Proton Injector of AGS-RHIC quadrupole, dipole, DTL, rfq 458
 
  • M. Okamura, B. Briscoe, J.M. Fite, V. LoDestro, D. Raparia, J. Ritter
    BNL, Upton, Long Island, New York
  • N. Hayashizaki
    RLNR, Tokyo
 
 

It is commonly preferred to have a short distance between an RFQ and a consequent DTL, however many devices has to be accommodated within a limited space. Our new medium energy beam transport line for proton beam is categorized as one of the severest cases. High field gradient quadrupoles (65 Tm) and newly designed steering magnets (6.5 mm in length) were fabricated considering the cross-talk effects. Also a new half wave length 200 MHz buncher is being studied. In the conference, the electro-magnetic field designs and the measured result will be discussed.

 
TUP031 A Side Coupled Proton Linac Module 30-35 MeV: First Acceleration Tests linac, acceleration, cyclotron, booster 467
 
  • V.G. Vaccaro
    Naples University Federico II and INFN, Napoli
  • S. Barone
    NRT, Aprilia
  • L. Calabretta, A. Rovelli
    INFN/LNS, Catania
  • C. De Martinis
    Universita' degli Studi di Milano & INFN, Segrate
  • L. Gini, D. Giove
    INFN/LASA, Segrate (MI)
  • S. Lanzone
    ADAM, Geneva
  • M.R. Masullo
    INFN-Napoli, Napoli
  • A.C. Rainò
    Bari University, Science Faculty, Bari
  • V. Variale
    INFN-Bari, Bari
 
 

ACLIP is a 3 GHz proton SCL linac designed as a booster for a 30 MeV commercial cyclotron. The whole accelerator is a 5 module structure coupled together. The final energy is 62 MeV well suitable for the therapy of ocular tumors. In order to treat deep-seated tumors the energy can be raised up to 230 MeV by adding a second linac. The possibility of using magnetrons, as the source of RF power, to reduce the overall cost of the machine, and the tile design (covered by a patent), named Back-to-Back Accelerating Cavity (BBAC), to efficiently accelerate protons starting from a low energy are two of the more relevant features of this project. The first module (from 30 to 35 MeV) has been full power RF tested in December 2008, showing that the design accelerating field could be easily reached. Then this module, along with all elements of the RF power setup, has been transferred to INFN-LNS in Catania at the end of April 2010 to carry out beam acceleration tests using a 30 MeV proton beam from the Superconducting Cyclotron. In this paper we will review the main features of the linac and discuss the results of the acceleration measurements carried out on this prototype.

 
TUP038 Matter-Radiation Interactions in Extremes linac, electron, klystron, controls 485
 
  • R.W. Garnett, M.S. Gulley
    LANL, Los Alamos, New Mexico
 
 

LANSCE has been the centerpiece of large-scale science at Los Alamos National Laboratory for many decades. Recently, funding has been obtained to ensure continued reliable operation of the LANSCE linac and to allow planning to enable the first in a new generation of scientific facilities for the materials community. The emphasis of this new facility is "Matter-Radiation Interactions in Extremes" (MaRIE) which will be used to discover and design the advanced materials needed to meet 21st century national security and energy security challenges. MaRIE will provide the tools scientists need to develop next-generation materials that will perform predictably and on-demand for currently unattainable lifetimes in extreme environments. The MaRIE facility is based on a high-power upgrade to the existing LANSCE proton linac, a new electron linac and associated X-ray FEL to provide additional probe beams, and new experimental areas. A conceptual description of this new facility and its requirements will be presented.

 
TUP045 RF and Heat Flow Simulations of the SARAF RFQ 1.5 MeV/nucleon Proton/Deuteron Accelerator rfq, simulation, resonance, linac 506
 
  • J. Rodnizki, Z. Horvitz
    Soreq NRC, Yavne
 
 

The SARAF 4-rod RFQ is operating at 176 MHz, designed to bunch and accelerate a 4 mA CW deuteron/proton beam to 1.5 MeV/u. The electrodes voltage for accelerating deuterons is 65 kV, a field of 22 MV/m. The RFQ injected power is induced by a loop coupler. The power needed to achieve this voltage is 250 kW, distributed along the 3.8 m RFQ length. This power density is approximately 3 times larger than that achieved in other 4-rod RFQs. At high power, local high surface currents in the RFQ might cause overheating which will lead to out-gassing and in turn to sparking. We used CST MWS to simulate the RF currents and fields in a 3D detailed model of the SARAF RFQ. The correct eigenmode was reproduced and both Qe and Qo are consistent with the measured values. The heat load generated by the simulated surface currents at critical areas along the RFQ was the input for thermal analysis using Ansys. Detailed results reproduced the experimental observation of several overheated regions in the RFQ, including the end flanges and the plungers. Further results predicted overheating at different regions which were subsequently measured and are now being improved by additional cooling.

 
TUP048 Experiences with the Fermilab HINS 325 MHz RFQ rfq, vacuum, ion, ion-source 515
 
  • R.C. Webber, T.N. Khabiboulline, R.L. Madrak, G.V. Romanov, V.E. Scarpine, J. Steimel, D. Wildman
    Fermilab, Batavia
 
 

The Fermilab High Intensity Neutrino Source program has built and commissioned a pulsed 325 MHz RFQ. The RFQ has successfully accelerated a proton beam at the design RF power. Experiences encountered during RFQ conditioning, including the symptoms and cause of a run-away detuning problem, and the first beam results are reported.

 
TUP065 Concept Design of CW SC Proton Linac Based on Spoke Cavity for China ADS cavity, linac, emittance, simulation 1
 
  • Z. Li
    Southwest University of Science and Technology, Mianyang, Sichuan
 
 

A system ADS study program has been proposed and organized by Chinese Academy of Sciences. As part of the study program, concept design of a 10mA 1.5GeV Continue Wave (CW) superconducting proton linac has been started in the Institute of High Energy Physics (IHEP). In this paper the design of the 325MHz part of this linac, which is composed of a room temperature Radio Frequency Quadrupole (RFQ), eight 4-cell room temperature Cross bar H-type (CH) cavities and three kinds of spoke cavities with total number of 78, is presented. The main parameters and detailed beam dynamic simulation results of the CH and spoke section are introduced.

 
TUP071 Research on Drift Tube Linac Model Cavity for CPHS DTL, rfq, cavity, linac 575
 
  • S.X. Zheng, X. Guan, J. Wei, H.Y. Zhang
    TUB, Beijing
  • J.H. Billen, L.M. Young
    TechSource, Santa Fe, New Mexico
  • Y. He, J. Li, D.-S. zhang
    NUCTECH, Beijing
  • J.H. Li
    CIAE, Beijing
  • J. Stovall
    CERN, Geneva
  • Y.L. Zhao
    IHEP Beijing, Beijing
 
 

The CPHS project in Tsinghua University plans to construct a 13 MeV linear accelerator to deliver a pulsed proton beam having an average beam current of 2.5 mA. A Drift Tube Linac (DTL), following a Radio Frequency Quadrupole accelerator(RFQ), will accelerate protons from 3 to 13MeV. The accelerating field and phase will be ramped to match the longitudinal restoring forces at the end of the RFQ. Likewise, the transverse focusing forces, provided by permanent-magnet quadrupole lenses (PMQs) will be programmed to match the transverse restoring forces at the end of the RFQ to avoid missmatch and avoid parametric resonances. We will present the main physics design parameters of CPHS DTL and describe the properties of the resonant cavity. We plan to apply electron beam welding technology exclusively in the fabrication of the drift tubes and will present the test results from our engineering prototyping program.

 
TUP076 Status of Beam Loss Evaluation at J-PARC Linac beam-losses, linac, cavity, background 590
 
  • A. Miura, N. Kikuzawa, T. Maruta, K. Yamamoto
    JAEA/J-PARC, Tokai-mura
  • Z. Igarashi, T. Miyao
    KEK, Ibaraki
  • M. Ikegami
    J-PARC, KEK & JAEA, Ibaraki-ken
  • H. Sako
    JAEA, Ibaraki-ken
  • S. Sato
    JAEA/LINAC, Ibaraki-ken
 
 

Since November, 2007, J-PARC Linac has been operated at 7.2kW beam power. During the operation, beam losses possibly caused by the H0 particles generated by the interaction between H- beam and residual gas in the transport line were observed in the SDTL (Separated-type Drift-Tube Linac) section. In the linac operation, Ar-CO2 gas proportional counters are employed for the measurement of beam loss, but they are also sensitive to background noise of X-ray emitted from RF cavities. In this section, protons, secondary hadrons and gamma rays would be mainly generated as a beam loss, but it is not easy to estimate real beam loss using the proportional counter. The plastic scintillation counters with less X-ray sensitivity and 3He proportional counters with high thermal neutron sensitivity will be also employed to measure the beam loss. The combination of these detectors would bring more accurate beam loss measurements with suppression of X-ray noise. A measurement of emission position and angle distributions of protons due to H- beam loss is being planed. This result would lead to clarify the source of beam loss. This paper reports status of beam loss evaluation using these detectors.

 
TUP085 Beam Cross Section Monitor for INR Linac ion, linac, vacuum, neutron 605
 
  • P.I. Reinhardt-Nickoulin, A. Feschenko, S.A. Gavrilov, I.V. Vasilyev
    RAS/INR, Moscow
 
 

The monitor to measure a transverse cross section of the accelerated beam has been developed and implemented in INR Linac. Operation of the monitor is based upon utilization of residual gas ionization. Ion flux cross section after extraction of the ions from the beam line by electrostatic field and subsequent energy separation in electrostatic analyzer reproduces a transverse cross section of the accelerator beam. Aμchannel plate intensifier followed by a phosphor screen is used to observe ion cross section. The image is optically transmitted to a CCD camera installed remotely and shielded for protection. The monitor enables to observe beam cross section, beam profiles and beam position, as well as their evolution in time within a wide range of beam intensities and energies. Monitor operation and parameters are described. Some experimental results are presented.

 
TUP090 Development of a Bunch Length Detector electron, optics, vacuum, resonance 617
 
  • J.Y. Kim, H.-C. Bhang, D.G. Kim
    SNU, Seoul
  • J.-W. Kim
    NCC, Korea, Kyonggi
 
 

A bunch length detector has been designed and constructed, which can measure current distributions inside the beam bunch. The device measures secondary electrons that are emitted when the beam hits a negatively biased thin target wire. Two main components of the device are an rf deflector to deflect secondary electrons vertically in correlation with the rf time of the beam bunch, and microchannel plate to detect the electrons after spatial discrimination. Rf properties of the rf deflector were first numerically analyzed, and a full-scale cold model was built and tested using a network analyzer. Microchannel plate detector was tested using a beta-emitting isotope source. The electron optics were calculated to design the structure of the detector, and the actual detector will soon be constructed and tested using a cw proton beam from a cyclotron.

 
TUP091 Energy and Energy Spread Measurements Using the Rutherford Scattering Technique for Tuning the SARAF Superconducting Linac cavity, emittance, rfq, diagnostics 620
 
  • J. Rodnizki, A. Perry, L. Weissman
    Soreq NRC, Yavne
 
 

The SARAF accelerator is designed to accelerate both deuteron and proton beams up to 40 MeV. Phase I of SARAF consists of a a 4-rod RFQ (1.5 MeV/u) and a superconducting module housing 6 half-wave resonators and 3 superconducting solenoids (4-5 MeV). The ions energy and energy spread were measured using the Rutherford scattering technique . This technique is used to tune the cavities to the desired amplitude and phase. The downstream HWR is used as a buncher and the beam energy spread as function of the bunching RF voltage is applied to estimate the longitudinal emittance. In this work, we present a longitudinal emittance measurement algorithm, which is based on the bunch energy spread as a function of the buncher's amplitude, similar to the standard algorithm that uses the bunches' temporal spread. The tuning and measured longitudinal parameters are in qualitative agreement with the predicted beam dynamics simulation.

 
TUP101 Wire Grid and Wire Scanner Monitors Design for the CERN LINAC 4 electron, ion, linac, scattering 650
 
  • F. Roncarolo, E. Bravin, M. Duraffourg, C. Dutriat, G.J. Focker, U. Raich, VC. Vuitton
    CERN, Geneva
  • B. Cheymol
    Université Blaise Pascal, Clermont-Ferrand
 
 

As part of the CERN LHC injector chain upgrade, LINAC4 will accelerate H- ions from 45 keV to 160 MeV. A number of wire grids and wire scanners will be used to characterize the beam transverse profile. This paper covers all monitor design aspects intended to cope with the required specifications. In particular, the overall measurement robustness, accuracy and sensitivity must be satisfied for different commissioning and operational scenarios. The physics mechanisms generating the wire signals and the wire resistance to beam induced thermal loads have been considered in order to determine the most appropriate monitor design in terms of wire material and dimensions.

 
TUP109 Large Acceptance Linac for Muon Acceleration linac, solenoid, cavity, acceleration 665
 
  • H.M. Miyadera, A.J. Jason, S.S. Kurennoy
    LANL, Los Alamos, New Mexico
 
 

Muon accelerators are studied for future neutrino factory and muon colliders (NF/MC). On the other hand, a compact muon accelerator can be applicable to muon radiography which is a promising probe to investigate large objects. We worked on simulation studies on a compact muon linear accelerator. The designed linac has a large energy and a phase acceptance to capture lower energy pion/muon (10 - 100 MeV) than the NF/MC scenario and accelerates them to 200 MeV without any beam cooling. Our current design adopts 805 MHz zero-mode normal-conducting cavities with 35 MV/m peak field*. The superconducting solenoids are used to provide 5-T focusing field on the normal conducting cavities. We developed a Monte Carlo simulations code to optimize linac parameters. Muon energy loss and scattering effects at the aperture windows are included, too. The simulation showed that about 10 % of the pion/muon injected into the linac can be accelerated to 200 MeV. Further acceleration can be done with superconducting linac.


* S. Kurennoy et al., IPAC 2010.

 
WE102 The Status of the SARAF Linac Project rfq, cavity, cryogenics, emittance 679
 
  • L. Weissman, D. Berkovits, I. Eliyahu, I. Gertz, A. Grin, S. Halfon, G. Lempert, I. Mardor, A. Nagler, A. Perry, J. Rodnizki
    Soreq NRC, Yavne
  • A. Bechtold
    NTG Neue Technologien GmbH & Co KG, Gelnhausen
  • K. Dunkel, M. Pekeler, C. Piel
    RI Research Instruments GmbH, Bergisch Gladbach
 
 

Phase I of the Soreq Applied Research Accelerator Facility, SARAF, has been installed and is currently being commissioned at Soreq NRC [1]. According to the Phase I design, SARAF should yield 2 mA proton and deuteron beams at energies up to 4 and 5 MeV, respectively. The status of the main Phase I components is reported. We further present beam commissioning results, which include acceleration of a 1 mA CW proton beam up to 3 MeV. Further improvements in the facility in order to achieve the desired performance are discussed.

 

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WE103 Status of Linac4 Construction at CERN linac, rfq, DTL, klystron 684
 
  • M. Vretenar
    CERN, Geneva
 
 

Linac4 is a 160 MeV normal-conducting H- linear accelerator which is being built at CERN in the frame of a program for increasing the luminosity of the LHC. The project started in 2008 and delivery of beam to the CERN accelerator chain is foreseen from early 2015. The new linac will be housed in an underground tunnel close to the present Linac2; a surface building will house RF and other infrastructure. The civil engineering work started in October 2008 will be soon completed. Installation of the infrastructure will take place in 2011, and from 2012 will be installed the main machine elements. The ion source is presently operational on a test stand, where it will be followed in 2011 by a 3 MeV RFQ under construction in the CERN workshops. Prototypes of the three different types of accelerating structures have been tested; construction of the 22 accelerating cavities has started, supported by a network of agreements with external laboratories and institutions. Commissioning will take place in stages, starting from January 2013. Starting in March 2014 is foreseen a six-month reliability run, in preparation for its role as the new source of particles for the CERN complex.

 
TH104 Power Coupler Developments for High Intensity Linacs cavity, linac, cryomodule, SRF 722
 
  • G. Devanz
    CEA, Gif-sur-Yvette
 
 

Recent developments and promising results are showing the feasibility of 1 MW power couplers for superconducting cavities accelerating high intensity proton beam for projects such as SPL, ESS, EURISOL.

 

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Slides

 
TH301 Beam Dynamics Studies for Multi-GeV Proton and H-minus Linacs linac, simulation, resonance, cavity 735
 
  • J.-P. Carneiro
    Fermilab, Batavia
  • B. Mustapha, P.N. Ostroumov
    ANL, Argonne
 
 

Significant advances were demonstrated in the design and computer simulations of multi-GeV proton and H-minus linacs. Several codes were applied for the simulation of 8 GeV linac and resulted to extremely good coincidence of all beam parameters. New procedures such as stripping of H-minus ions due to various mechanisms were implemented into the tracking code. The author of this presentation has several publications in PRSTAB and Nuclear Instruments on various aspects of beam dynamics for 8 GeV linac.

 

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Slides

 
THP004 Layout and Machine Optimisation for the SPL at CERN cavity, linac, HOM, klystron 761
 
  • F. Gerigk, S. Atieh, S. Calatroni, O. Capatina, E. Ciapala, M. Eshraqi, L.M.A. Ferreira, R. Garoby, M. Hernandez Flano, W. Höfle, E. Lebbos, A.M. Lombardi, E. Montesinos, Th. Otto, V. Parma, P.A. Posocco, T. Renaglia, M. Schuh, V. Vlachoudis, W. Weingarten, S. Weisz
    CERN, Geneva
  • R. Calaga
    BNL, Upton, Long Island, New York
 
 

During the past 2 years the Superconducting Proton Linac (SPL) study has grown into an international collaboration with the goal of optimising the architecture of a pulsed superconducting (SC) high-power proton linac. This effort includes the study and prototyping of major technical components, such as SC high-gradient cavities, power couplers, the RF distribution system, HOM couplers, cryo-modules, focusing elements, etc. Even though the effort is driven by CERN specific needs, the established design principles are valid for a range of superconducting linac projects. In this paper we report on the latests decisions concerning the machine architecture and on the ongoing R&D effort for technical components.

 
THP006 Accuracy Determination of the CERN LINAC4 Emittance Measurements at the Test Bench for 3 and 12 MeV emittance, space-charge, DTL, linac 767
 
  • F. Roncarolo, E. Bravin, U. Raich
    CERN, Geneva
  • B. Cheymol
    Université Blaise Pascal, Clermont-Ferrand
 
 

The CERN LINAC4 commissioning will start in 2011, at first in a laboratory test stand where the 45 KeV H- source is already installed and presently tested, and later in the LINAC4 tunnel. A movable diagnostics bench will be equipped with the necessary sensors capable of characterizing the H- beam in different stages, from 3 MeV up to the first DTL tank at 12 MeV. In this paper we will discuss the accuracy of the transverse emittance measurement that will be performed with the slit-grid method. The system's mechanical and geometric parameters have been determined in order to achieve the required resolution and sensitivity. Space charge effects during the beam transfer from the slit to the grid and scattering effects at the slit have been considered to determine the overall emittance measurement accuracy.

 
THP055 Multipactor Simulations of the SPL Power Coupler multipactoring, electron, simulation, cavity 878
 
  • G. Burt, P.K. Ambattu, A.C. Dexter
    Cockcroft Institute, Lancaster University, Lancaster
  • R. Calaga
    BNL, Upton, Long Island, New York
  • E. Montesinos
    CERN, Geneva
 
 

Multipactor is a limiting factor in many RF power couplers. The SPL coupler is proposed to have a conical matching section between the window and the coaxial section however this section must be checked for multipactor. Multipactor simulations of the coupler up to a few MW's of power were performed using a variety of different codes and the results were compared. Simulations were performed in the conical and straight coaxial sections.

 
THP058 Power Supply System for Klystron in J-PARC Linac linac, klystron, status, cathode 887
 
  • M. Kawamura, Y. Fukui, F. Naito
    KEK, Ibaraki
  • E. Chishiro, H. Suzuki, M. Yamazaki
    JAEA, Ibaraki-ken
  • K. Hasegawa, S. Shinozaki
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
 
 

This report will describe the present status of the power supply systems (PS systems) for the klystrons in the J-PARC (Japan Proton Accelerator Research Complex) linac. The technical specification, the operating experience, and the upgrade plan, of the PS systems will be presented in this report. Now the energy of the J-PARC linac is 181MeV, and the linac includes twenty 324MHz klystrons. In 2012, the energy will be upgraded to 400MeV, and the linac will include twenty 324MHz klystrons and twenty-five 972MHz klystrons. The klystrons are the modulating-anode types. The PS systems include the High voltage DC power supplies (DCPSs) and the anode-modulators. One DCPS drives one or four klystrons, and one anode-modulator drives one klystron.

 
THP069 Stripping of H-minus Beams by Residual Gas in the Linac at the Los Alamos Neutron Science Center linac, ion, background, vacuum 908
 
  • R.C. McCrady
    LANL, Los Alamos, New Mexico
 
 

The linear accelerator at the Los Alamos Neutron Science Center (LANSCE) accelerates both protons and H-minius ions using Cockroft-Walton-type injectors, a drift-tube linac and a side-coupled linac. The vacuum is maintained in the range of 10-6 to 10-7 Torr; the residual gas in the vacuum system results in some stripping of the electrons from the H-minus ions resulting in beam spill and the potential for unwanted proton beams delivered to experiments. We have measured the amount of fully-stripped H-minus beam (protons) that ends up at approximately 800MeV in the beam switchyard at LANSCE using image plates as very sensitive detectors. I will present the motivation for the measurement, the measurement technique and results, and calculations to model the results and possible mitigation schemes.

 
THP071 ExB Chopper System for High Intensity Proton Beams high-voltage, simulation, dipole, vacuum 914
 
  • C. Wiesner, L.P. Chau, H. Dinter, M. Droba, N.S. Joshi, O. Meusel, I. Müller, U. Ratzinger
    IAP, Frankfurt am Main
 
 

High intensity beams which are increasingly needed for a variety of applications pose new challenges for beam chopping. An ExB chopper system for proton beams of up to 200 mA and repetition rates of up to 250 kHz is under development at IAP. It will be tested and installed in the low energy section of the Frankfurt Neutron Source FRANZ at beam energies of 120 keV. The chopper consists of a static magnetic dipole field and a pulsed electric field in a Wien filter-type ExB configuration. The electric field temporarily compensates the magnetic deflection thus creating a proton pulse in forward direction, while the duty cycle of the electric field is minimized in order to reduce the risk of voltage breakdowns. Downstream of the chopper a septum will be used to separate the beams ensuring dumping outside the transport line in order to avoid uncontrolled power deposition and the resultant production of secondary particles. Numeric field optimizations and beam simulations including secondary electron effects are presented. Measurements of the high voltage pulse generator based on MOSFET technology and capable of generating 12 kV at 250 kHz as well as beam deflection experiments are shown.

 
THP086 Beam Transport in a Proton Dielectric Wall Accelerator* focusing, beam-transport, quadrupole, emittance 941
 
  • Y.-J. Chen, D.T. Blackfield, G.J. Caporaso, S.A. Hawkins, S.D. Nelson, B. R. Poole
    LLNL, Livermore, California
 
 

Compact dielectric wall (DWA) accelerator technology is being developed at the Lawrence Livermore National Laboratory [1]. The DWA accelerator's beam tube is a stack of high gradient insulators, consisting of alternating layers of insulators and conductors. Characteristically, insulators' surface breakdown thresholds go up as the applied voltages' pulse width goes down. To attain the highest accelerating gradient in the DWA accelerator, the accelerating voltage pulses should have the shortest possible duration. This can be done by appropriately timing the switches in the transmission lines, which feed the continuous HGI tube. The accelerating voltage pulses arrive at the accelerator axis along the beam tube at different times so as to appear to the charged particle bunch as a traveling accelerating voltage wave. We have studied the beam transport in a baseline DWA configuration by performing PIC simulations using the 3-D, EM PIC code, LSP [2]. Sensitivity of the output beam parameters to the switch timing will be presented. In addition to the baseline configuration, various alternative focusing schemes will be discussed.


[1] G. J. Caporaso, Y-J Chen and S. E. Sampayan, "The Dielectric Wall Accelerator", Rev. of Accel. Sci. and Tech., vol. 2, p. 253 (2009).
[2] Alliant Techsystems Inc., http://www.lspsuite.com/.

 
THP113 Design of the 2.45 GHz ECR Proton Source and LEBT in CPHS (Compact Pulsed Hadron Source) rfq, neutron, ion, plasma 1001
 
  • Z. Feng, X. Guan, J. Wei, H.Y. Zhang
    TUB, Beijing
  • Z.W. Liu, H.W. Zhao
    IMP, Lanzhou
 
 

Responding to the demand of accelerator front inject system of the Compact Pulsed Hadron Source (CPHS) in Tsinghua university in 2009, an electron cyclotron resonance (ECR) proton source (2.45 GHz, 1.5 KW) and a low-energy-beam-transport (LEBT) system are designed and manufacted. In this source, the H2 plasma is restricted by an axial magnetic field shaped by the source body produced by an all-permanent-magnet design (NdFeB rings). The 50-keV pulsed proton beam (50 Hz/0.5 ms) extracted by a four-electrode extraction system from the proton source passes through the LEBT system (1283 mm long), which is consist of two solenoid lens, two steering magnets and a cone configuration optically matches to the RFQ where the Twiss parameters α=1.354, β=7.731. The beam with 97% space charge neutralization rate has been simulated at 100 mA, 150 mm.mrad RFQ output current by Trace-3D and PBGUN. In this study, we describe the design of the proton source and LEBT technical systems along with intended operation.

 
THP116 Tests of the Versatile Ion Source (VIS) for High Power Proton Beam Production emittance, plasma, extraction, permanent-magnet 1010
 
  • S. Gammino, G. Castro, L. Celona, G. Ciavola, D. Mascali, R. Miracoli
    INFN/LNS, Catania
  • G. Adroit, O. Delferrière, R. Gobin, F. Senée
    CEA, Gif-sur-Yvette
  • F. Maimone
    GSI, Darmstadt
 
 

The sources adapted to beam production for high power proton accelerators must obey to the request of high brightness, stability and reliability. The Versatile Ion Source (VIS) is based on permanent magnets (maximum value around 0.1 T on the chamber axis) producing an off-resonance microwave discharge. It operates up to 80 kV without a bulky high voltage platform, producing several tens of mA of proton beams and monocharged ions. The microwave injection system and the extraction electrodes geometry have been designed in order to optimize the beam brightness. Moreover, the VIS source ensures long time operations without maintenance and high reliability in order to fulfil the requirements of the future accelerators. A description of the main components and of the source performances will be given. A brief summary of the possible options for next developments of the project will be also presented, particularly for pulsed mode operations, that are relevant for future projects.