LINAC2014 - List of Keywords (target)

Paper	Title	Other Keywords	Page
MOPP010	Low Charge State Laser Ion Source for the EBIS Injector	ion, injection, laser, electron	64
	M. Okamura, J.G. Alessi, E.N. Beebe, T. Kanesue, C.J. Liaw, V. LoDestro, A.I. Pikin, D. Raparia, J. Ritter BNL, Upton, Long Island, New York, USA Y. Fuwa, S. Ikeda, M. Kumaki RIKEN, Saitama, Japan
	Funding: NASA In March 2014, we have successfully commissioned a newly designed low charge high brightness laser ion source (LIS) which delivers various singly charged heavy ions to the electron beam ion source (EBIS) at Brookhaven National Laboratory. Now the LIS is used at routine operation of the RHIC-AGS accelerator complex and is providing stable less-contaminated beams. The laser power density was optimized to provide singly charged ions with low material consumption rate. The nominal laser energy on the target is around 500 mJ with 1064 nm Nd:YAG of the wave length. The induced plasma by the laser is transported through a 3 m pipe to stretch ion beam pulse length to match the EBIS’s requirement and the degradation of the beam current caused by the long drift section of the pipe can be compensated by a longitudinal magnetic filed induced by a coil surrounding the pipe. We also employed a twin laser system to extend the beam width further. At the conference, we will discuss the effect of the new LIS on the various accelerated beams through the EBIS, RFQ and IH-linac.

MOPP011	Reliability and Intensity Upgrade for 200 MeV Linac at Brookhaven National Laboratory	linac, detector, operation, ion	67
	D. Raparia, J.G. Alessi, B. Briscoe, D.M. Gassner, O. Gould, T. Lehn, V. Lo Destro, J. Ritter, W. Shaffer, A. Zelenski BNL, Upton, Long Island, New York, USA
	Brookhaven 200 MeV H⁻ linac has been operating for last 44 years and providing beam to nuclear physics program and isotope program. Two upgrade programs are in progress to make machine more reliable and to double the intensity. This paper will discuss in detail these upgrade programs.

MOPP038	Longitudinal Bunch Profile Monitoring at the ESS Linac	linac, simulation, proton, neutron	143
	I. Dolenc Kittelmann, B. Cheymol ESS, Lund, Sweden
	The European Spallation Source (ESS), which is currently under construction, will be a neutron source based on 5MW, 2GeV proton linac. This high intensity linac will among other beam instrumentation require longitudinal bunch profile monitors. These shall be used during the commissioning phase and start-up periods for beam dynamics optimization and beam loss reduction. The paper focuses on the preliminary studies concerning the longitudinal bunch profile monitoring at the ESS linac.

MOPP076	Construction of an Accelerator-based BNCT Facility at yhe Ibaraki Neutron Medical Research Center	neutron, linac, rfq, klystron	230
	M. Yoshioka, H. Kobayashi, T. Kurihara, S.-I. Kurokawa, H. Matsumoto, N. Matsumoto KEK, Ibaraki, Japan T. Hashirano, T. Sugano MHI, Hiroshima, Japan F. Hiraga Hokkaido University, Sapporo, Japan H. Kumada, Su. Tanaka Tsukuba University, Graduate School of Comprehensive Human Sciences, Ibaraki, Japan A. Matsumura, H. Sakurai Tsukuba University, Ibaraki, Japan N. Nagura, T. Ohba Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan T.N. Nakamoto, T. Zagar Cosylab, Ljubljana, Slovenia T. Nakamura JAEA, Ibaraki-ken, Japan T. Ouchi ATOX, Ibaraki, Japan
	An accelerator-based BNCT (Boron Neutron Capture Therapy) facility is being constructed at the Ibaraki Neutron Medical Research Center. It consists of a proton linac of 80kW beam power with 8 MeV energy and 10mA average current, a beryllium target, and a moderator system to provide an epi-thermal neutron flux enough for patient treatment. The technology choices for this present system were driven by the need to site the facility in a hospital and where low residual activity is essential. The maximum neutron energy produced from an 8 MeV-proton is 6 MeV, which is below the threshold energy of the main nuclear reactions which produce radioactive products. The down side of this technology choice is that it produces a high density heat load on the target so that cooling and hydrogen aniti-blistering amelioration prevent sever challenges requiring successful R&D progress. The latest design of the target and moderator system shows that a flux of 4×10⁹ epi-thermal neutrons / cm² / sec can be obtained. This is much higher than the flux from the existing nuclear reactor based BNCT facility at JAEA ( JRR-4).

MOPP077	Electron-Driven Positron Capture Simulation for ILC	positron, electron, linac, booster	233
	Y. Seimiya, M. Kuriki HU/AdSM, Higashi-Hiroshima, Japan S. Kashiwagi Tohoku University, Research Center for Electron Photon Science, Sendai, Japan T. Okugi, T. Omori, M. Satoh, J. Urakawa KEK, Ibaraki, Japan T. Takahashi Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan
	ILC (International Linear Collider) is a next high-energy physics project to study the Higgs property as detail as possible and new phenomena beyond standard model. In ILC, the positron beam is produced by converting gamma rays from undulator radiations. To obtain gamma rays as undulator radiation, the electron beam for collision (150 GeV or more) is used. This positron generation scheme is a totally new approach. From project point of view, it is desirable to have a technical backup as a replacement of the undulator scheme. We propose an ILC positron source based on the conventional electron driven scheme. In this scheme, positron beam is generated from electromagnetic shower in a heavy target material where electron beam is injected. By manipulating the beam time structure to relax the heat load on the production target, the scheme can be feasible technically. In this study, positron capture in the electron driven scheme is simulated from the positron production to the positron damping ring, to demonstrate that an enough amount of positron can be generated and captured with a controllable heat load on the target.
	Poster MOPP077 [0.879 MB]

MOPP088	MUNES a Compact Neutron Source for BNCT and Radioactive Wastes Characterization	neutron, rfq, proton, quadrupole	261
	A. Pisent, P. Colautti, E. Fagotti INFN/LNL, Legnaro (PD), Italy
	At INFN LNL (Legnaro Italy) it has been built a high intensity Radio Frequency Quadrupole (RFQ) structure, able to produce a 5 MeV proton beam of 30 mA. Coupled with a Be target such a beam can generate a neutron flux of 10¹⁴ n/s, with a spectrum centered in the MeV region (that has been recently characterized in detail at LNL accelerators). This neutron flux can be moderated to generate a thermal or epithermal source for BNCT with very little contamination of energetic form energetic neutron and gamma. Since the approval of MUNES project (in 2012) the high technology issues related to a compact neutron source to be installed in an Hospital environment have been faced. In particular for the powering of the accelerating structure an innovative system, completely based on solid state amplifiers, has been developed and ordered to industry. An outline of MUNES design and the status of the project will be given in the paper.

MOPP109	Ion Beam Acceleration in Neutron Tube	electron, ion, neutron, space-charge	310
	V.I. Rashchikov MEPhI, Moscow, Russia A.S. Plastun ITEP, Moscow, Russia
	Deuteron beam acceleration in ion-optic system of gas-filled neutron tubes was investigated. PIC code SUMA "" used for computer simulation of ionization and knock on processes and there influence on deuteron beam parameters. When deuteron and ionized particles own space charge forces become the same order of magnitude as external one, virtual cathode may occurs. It is happened because of injected from ion source deuterons cannot overcome their own space charge potential wall and move in transverse direction. However, electrons, produced by ionization, are trapped within the deuteron beam space charge potential wall and decrease it significantly. Thus, space charge neutralization of deuteron beams by electrons, may considerably increase target current and, as a result, output neutron flow. Moreover, own longitudinal electric field rise near the target leads to reduction of accelerating electrode – target potential wall, which was made to prevent knock on emission from the target. As a result, additional knocked on electrons may appear in the region and should be taken into account. The data obtained were compared with experimental results. A.N. Didenko, V.I. Rashchikov, V.E. Fortov, Technical Physics, Vol. 56, No. 10,pp. 1535–1538, 2011

MOPP138	Fabrication and Measurements of 500 MHz Double Spoke Cavity	cavity, electron, simulation, radiation	385
	H. Park, J.R. Delayen JLab, Newport News, Virginia, USA J.R. Delayen, C.S. Hopper, H. Park ODU, Norfolk, Virginia, USA
	The 500 MHz double spoke cavity has been designed for a high velocity application such as a compact electron accelerator at Center for Accelerator Science at Old Dominion University and is being built at Jefferson Lab. The geometry specific to the double spoke cavity requires a variety of tooling and fixtures. Also a number of joints are expected to make it difficult to maintain the geometric deviation from the design minimal. This paper will report the fabrication technique, resulting tolerance from the design, and comparison between the measurements and simulations.
	Poster MOPP138 [2.144 MB]

TUPP003	4 K Alignment of Superconducting Quarter-Wave Cavities and 9 T Solenoids in the ATLAS Intensity Upgrade Cryomodule	cryomodule, solenoid, alignment, cavity	443
	S.H. Kim, Z.A. Conway, W.G. Jansma, M. Kedzie, M.P. Kelly, P.N. Ostroumov ANL, Argonne, Illinois, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under contract number DE-AC02-06CH11357. The superconducting cavities and, especially, the magnets in high intensity ion linacs need to be aligned to the beam with typical transverse tolerances of 0.25 mm and 0.1 degrees at temperatures of 1.8 – 4.5 K. This is necessary to limit the emittance growth and minimize the beam losses. A new cryomodule with 7 superconducting quarter-wave resonators and 4 superconducting solenoids has been installed and is now operated at the Argonne Tandem Linear Accelerator System (ATLAS). We developed the techniques necessary to assemble the superconducting components in this cryomodule at room temperature so that they are aligned to the beam axis at 4.5 K. We achieved transverse alignment tolerances of <0.2 mm RMS. In this paper, we will present the details of the alignment hardware, procedures and results.
	Slides TUPP003 [0.834 MB]

TUPP004	An In-flight Radioactive Ion Separator Design for the ATLAS Facility	dipole, ion, quadrupole, simulation	446
	B. Mustapha, B. Back, C.R. Hoffman, B.P. Kay, J.A. Nolen, P.N. Ostroumov ANL, Argonne, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. An in-flight radioactive beam separator, named AIRIS, is being designed to enhance the radioactive beam capabilities of the ATLAS facility at Argonne. In order to serve all the experimental areas while maintaining the stable beam capabilities, the separator design is of broadband type. This design allows the selected radioactive beam to come back on the ATLAS beam line while stable beams continue on the same straight line with the separator turned off. The separation is performed in two steps, the first is magnetic in a chicane made of four magnets and four multipoles, while the second uses an rf sweeper taking advantage of the time separation between the beam of interest and potential contaminants including the primary beam tail. We will report on the progress of the AIRIS design effort with special emphasis on the performance of the rf sweeper.

TUPP015	Status on Airix Restart	electron, induction, timing, operation	462
	A. Georges, J. Beaubernard, V. Bernigaud, L. Buche, Y. Collet, S. Combacon, B. Gouin, G. Grandpierre, J.K. Kranzmann, L. Magnin, R. Nicolas, D. Pierre, F. Poulet, Y. Tailleur, J-L. Verstraete, J. Magnan CEA, Pontfaverger-Moronvilliers, France
	The Airix accelerator has been moved from Moronvilliers to Valduc to be part of the EPURE facility. Airix has been refurbished and restarted. This paper presents the first results and quantification of performances at its new location. M.Mouillet et al., “First results of AIRIX induction accelerator”,XXth LINAC cf.,p.491(2000) *H.Dzitko et al., "operationnal efficiency of Airix accelerator since its commissioning",IPAC2012,p.4017

TUPP022	RF Tuning of a S-band Hybrid Buncher for Injector Upgrade of LINAC II at DESY	linac, electron, simulation, experiment	478
	Y.C. Nie, M. Hüning, C. Liebig, M. Schmitz DESY, Hamburg, Germany
	LINACII at DESY currently provides 450 MeV electrons for the synchrotron radiation source PETRAIII. The injector upgrade of it aims to improve its reliability and mitigate the radiological activation due to electron losses at hundreds of MeV. Therefore, a 2.998 GHz hybrid buncher has been developed and will be installed in between a pre-buncher and LINAC II. It comprises a 1-cell standing-wave (SW) section for rapid acceleration and a 13-cells travelling-wave (TW) section for further bunching and acceleration. This paper focuses on its rf tuning procedure. The tuning strategy combines a non-resonant bead-pull measurement of complex electric field and a linear model for local reflection coefficient calculation. The tuning result is satisfying. Field unflatness of the TW section has been improved from ±9% to ±4%, and field in the SW section has been enhanced significantly. By using ASTRA simulation, it has been verified that the residual detuning of the structure is acceptable in view of beam dynamics performance.

TUPP083	Design and Analysis of Slow Tuner in the Superconducting Cavity of RISP	cavity, superconducting-cavity, niobium, SRF	616
	M.O. Hyun, H.C. Jung, H.J. Kim IBS, Daejeon, Republic of Korea
	Funding: This work was supported by the Rare Isotope Science Project of Institute of Basic Science funded by the Ministry of Science, ICT and Future Planning and National Research Foundation. Superconducting cavity is one of the most complex systems from the view of mechanical engineering, which is installed and operated in the superconducting linear accelerator. In order to operate SC cavity properly and precisely, superconducting cavity needs many sub-systems, including power coupler for applying RF power inside cavity, and liquid helium jacket for cooling cavity until reaching to the superconducting conditions. And, also cavity needs frequency tuning system for adjusting operating frequency when RF frequency of cavity is changed with outer disturbances such as liquid helium fluctuation, mechanical deformation due to vacuum condition of cavity. Generally, this tuning system is called as a tuner. There are two types of tuner, one is slow tuner which operates with motor, and the other is fast tuner which operates with piezo-electric actuator. This paper describes about design process and analysis results about slow tuner.

TUPP088	The Fabrication of the β=0.12 HWR at RISP	niobium, cavity, vacuum, electron	628
	G.-T. Park, H.J. Cha, Y. Jung, H. Kim, W.K. Kim IBS, Daejeon, Republic of Korea
	At RISP, the superconducting cavities have been developed to construct RAON, the heavy ion accelerator. Among the cavities, the fabrication of the QWR (Quarter wave resonator) and the HWR (Half wave resonator)are complete. The detailed fabrication processes including material inspection, forming, the electron beam welding, and the clamp up test are described.

TUPP100	Operation Of The Versatile Accelerator Driving the Low Power ADS GUINEVERE at SCK•CEN	neutron, operation, ion, ion-source	659
	M.A. Baylac, A. Billebaud, P. Boge, D. Bondoux, J. Bouvier, S. Chabod, G. Dargaud, E. Froidefond, E. Labussière, R. Micoud, S. Rey LPSC, Grenoble Cedex, France A. Kochetkov, J. Mertens, F. Van Gestel, C. Van Grieken, B. Van Houdt, G. Vittiglio SCK•CEN, Mol, Belgium F.R. Lecolley, J.L. Lecouey, G. Lehaut, N. Marie-Nourry CNRS/IN2P3/LPC CAEN, Caen, France
	GUINEVERE provides a low power accelerator driven system (ADS) to investigate on-line reactivity monitoring and operational procedures of an ADS. It consists of a versatile neutron source, GENEPI-3C, driving the fast sub-critical core, VENUS-F, in SCK•CEN (Belgium). GENEPI-3C is an electrostatic accelerator generating 14 MeV neutrons by bombarding a 250 keV deuteron beam onto a tritium target located within the reactor core. This accelerator produces alternatively continuous beam (up to 1 mA DC), possibly chopped with fast and adjustable interruptions, or short and intense deuteron bunches (~25 mA peak, 1 μs). This paper presents the facility and assesses the 2 years of coupled operation of the accelerator to the reactor.
	Slides TUPP100 [0.969 MB]

TUPP101	Vertical Electro-Polishing of Nb Single-Cell Cavity Using Cathode with Variable-Geometry Wings and Its Results of Vertical Test	cavity, cathode, power-supply, experiment	662
	K.N. Nii, V. Chouhan, Y.I. Ida, T.Y. Yamaguchi MGH, Hyogo-ken, Japan P. Carbonnier, F. Éozénou, C. Servouin CEA/DSM/IRFU, France H. Hayano, S. Kato, H. Monjushiro, T. Saeki, M. Sawabe KEK, Ibaraki, Japan K. Ishimi MGI, Chiba, Japan C. Madec, L. Maurice CEA/IRFU, Gif-sur-Yvette, France
	Marui Galvanizing Co. Ltd. has been studying Vertical Electro-Polishing (VEP) on Nb superconducting accelerator cavity with the goal of mass-production and cost-reduction of Electro-Polishing (EP) process in collaboration with KEK and CEA Saclay. And we invented variable-geometry wings cathode for VEP process to get uniform distributions of both electric current and EP solution flow. Using this cathode, we performed various tests of VEP with Nb single-cell cavities. In this article, we will report the results of vertical test of Nb single-cell cavity which is VEP’ed by cathode with variable-geometry wings.

WEIOB02	SARAF Phase-I Proton / Deuteron Linac Beam Operation Status	operation, rfq, proton, neutron	770
	A. Kreisel, A. Arenshtam, Y. Ben Aliz, D. Berkovits, Y. Buzaglo, O. Dudovich, Y. Eisen, I. Eliyahu, G. Feinberg, I. Fishman, I.G. Gertz, A. Grin, S. Halfon, Y.F. Haruvy, T. Hirsch, D. Hirschmann, Z. Horvitz, B. Kaizer, D. Kijel, J. Luner, I. Mor, J. Rodnizki, G. Shimel, A. Shor, I. Silverman, D. Vartsky, L. Weissman, E. Zemach Soreq NRC, Yavne, Israel
	SARAF Phase-I linac is the first accelerator to demonstrate acceleration of variable energy 2 mA CW proton beam. Such intense beam is used in SARAF Phase-I to irradiate a liquid lithium jet target for nuclear astrophysics studies. Several improvements were necessary to allow beam operation with such high current. The improvements include a DC bias that was introduced on the cavity RF coupler to reduce coupler heating. A new slow chopper was commissioned to enable increase the current by increasing the duty cycle with fewer changes in the beam optics. A beam dump was developed to allow beam studies of a 2 mA CW proton beam. The beam dump is based on tungsten pins which distributes, by radiation, the high beam power over a large area which is then easily water cooled. While most of beam tuning is done using a low intensity pilot beam, some nondestructive methods were studied to monitor the high intensity beam. These include a current transformer and a residual gas monitor (RGM) to monitor beam transverse distribution. Additional valuable information about the beam current and energy is gained from measurements of the nuclear reaction products of the proton on lithium targets.
	Slides WEIOB02 [3.027 MB]

WEIOB03	Status of RAON Heavy Ion Accelerator Project	ion, rfq, cavity, linac	775
	D. Jeon, H.J. Kim IBS, Daejeon, Republic of Korea
	Funding: This work was supported by the Institute for Basic Science funded by the Ministry of Science, ICT and Future Planning (MSIP) and the NRF of Korea under Contract 2013M7A1A1075764. Construction of the RAON heavy ion accelerator facility is under way in Korea to build the In-flight Fragment (IF) and Isotope Separation On-Line (ISOL) facilities to support cutting-edge researches in various science fields. At present prototyping of major components are proceeding including 28 GHz ECR ion source, RFQ, superconducting cavities, magnets and cryomodules. Superconducting magnets of 28 GHz ECR ion source are fabricated and tested. First article of prototype superconducting cavities are delivered that were fabricated through domestic vendors. Prototype HTS quadrupole is under development. Progress report of the RAON accelerator systems is presented.
	Slides WEIOB03 [6.228 MB]

THPP007	Uniform Current Density for BLIP Target at Brookhaven 200 MeV Linac	linac, octupole, dipole, isotope-production	850
	D. Raparia, B. Briscoe, P. Cerniglia, R. Connolly, C. Cullen, D.M. Gassner, R.L. Hulsart, R.F. Lambiase, V. Lo Destro, L.F. Mausner, R.J. Michnoff, P. Thieberger, M. Wilinski BNL, Upton, Long Island, New York, USA
	Bulk of the beam from the linac is used for Brookhaven linac isotope producer (BLIP). The average current from the linac is up 125 uA. At this current BLIP has several target failures and yield uncertainty due to partially melted target salt. To reduce current density, we have tried octupoles in the past but did not produce uniform beam as calculated due to the x-y coupling present in the linac. A beam painting scheme with help of one x and y steers with 90 phase leg at 5 kHz will provide desire current density at the target. This paper discuss beam optics of the blip transport line and beam footprint on the target with given constrains.

THPP032	Magnetic Characterization of Fast-Pulsed Quadrupole Magnets for Linac4	quadrupole, linac, flattop, power-supply	909
	S. Kasaei, M.C.L. Buzio, O. Crettiez, V. Della Selva, L. Fiscarelli, J. Garcia Perez, J.-B. Lallement CERN, Geneva, Switzerland
	Linac4, currently being built at CERN, includes 24 quadrupole magnets characterized by narrow apertures and fast excitation cycles which make accurate magnetic measurements challenging. This paper describes the method used for the measurement, which is a combination of techniques based on stretched wire, rotating and fixed search coils. We show how these different instruments can be used in a complementary way to derive information on different aspects of the magnetic behaviour, such as the impact of hysteresis and dynamic eddy current effects. We summarize the results of the series measurement campaign, which include field strength, harmonic components, and the offset and orientation of the magnetic axis. Finally, we discuss the relevance of these measurements as their impact to the operation of the linac.

THPP079	Prototyping Progress of SSR1 Single Spoke Resonator for RAON	cavity, simulation, vacuum, heavy-ion	1
	H.J. Cha, M.O. Hyun, D. Jeon, H.C. Jung, H.J. Kim IBS, Daejeon, Republic of Korea
	The fabrication of prototypes for four different types of superconducting cavities (QWR, HWR, SSR1, and SSR2) for the Korean heavy ion accelerator, “RAON” is in progress. In this presentation, we report the current status of the SSR1 cavity (β=0.3 and f=325 MHz) prototype fabrication based on the technical designs. The issues when forming the niobium cavities such as pressing, machining, electron beam welding are reviewed. The RF testing for the prototypes, which will be done in near future, is also discussed.

THPP098	Vertical Electropolishing of Nb Coupon Cavity and Surface Study of the Coupon Samples	cathode, cavity, experiment, superconducting-RF	1080
	V. Chouhan, Y.I. Ida, K.N. Nii, T.Y. Yamaguchi MGH, Hyogo-ken, Japan H. Hayano, S. Kato, H. Monjushiro, T. Saeki, M. Sawabe KEK, Ibaraki, Japan K. Ishimi MGI, Chiba, Japan
	We have been carrying out vertical electropolishing (VEP) of 1.3 GHz Nb cavities for the ILC for 2 years. In this article we present VEP of a single cell Nb coupon cavity containing 6 Nb disk type coupons located at beam pipes, irises and equator positions of the cavity. VEP experiments were performed using our special ninja-cathode newly developed and a straight rod cathode in order to observe and compare the homogeneity of electropolishing (EP) and surface quality on the entire surface of the single cell cavity. EP current was measured for the individual coupons under different EP conditions in order to study the EP phenomenon on the different positions of the cavity. The surfaces of the coupons were analyzed by x-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDX). This article describes VEP and surface analysis results in detail.

THPP130	Development of FPGA-based Predistortion-type Linearization Algorithms for Klystrons within Digital LLRF Control Systems for ILC-like Electron Accelerators	klystron, controls, LLRF, FPGA	1162
	M. Omet Sokendai, Ibaraki, Japan B. Chase, P. Varghese Fermilab, Batavia, Illinois, USA T. Matsumoto, S. Michizono, T. Miura, F. Qiu KEK, Ibaraki, Japan
	Two different kinds of predistortion-type linearization algorithms have been implemented and compared on an FPGA within the digital LLRF control system the Advanced Superconducting Test Facility (ASTA) at the Fermi National Accelerator Laboratory (FNAL). The algorithms are based on 2nd order polynomial functions and lookup tables with interpolation by which complex correction factors are obtained. The algorithms were tested in an actual setup including a 5 MW klystron and a superconducting 9-cell TESLA-type cavity at ASTA. By this a proof of concept was demonstrated.
	Poster THPP130 [2.411 MB]

THPP137	Present Status of the 3 MeV Proton Linac at Tsinghua University	linac, rfq, proton, status	1182
	Q.Z. Xing, C. Cheng, C.T. Du, L. Du, T. Du, X. Guan, C. Jiang, C.-X. Tang, X.W. Wang, H.Y. Zhang, S.X. Zheng TUB, Beijing, People's Republic of China W.Q. Guan, Y. He, J. Li NUCTECH, Beijing, People's Republic of China B.C. Wang NINT, Xi'an, People's Republic of China
	We present, in this paper, the present status of the 3 MeV high current proton Linac for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. The ECR ion source produces 50 keV proton beam which is accelerated to 3 MeV by the downstream RFQ accelerator. The RFQ accelerator has been conditioned to 50 Hz/500 μs with the input power of 442 kW. Proton beam with the peak current of 30 mA, pulse length of 100 μs and repetition rate of 50 Hz has been delivered to the Beryllium target to produce the neutron since July 2013. The status of the development of the Drift Tube Linac is also presented in this paper. The beam energy will be enhanced to 13 MeV after the DTL is ready in 2015.

FRIOB03	Prospects for Accelerator-Driven Thorium Systems	neutron, proton, cyclotron, experiment	1213
	J.-P. Revol iThEC, Geneva, Switzerland
	To meet the tremendous world energy needs, systematic R&D has to be pursued to replace fossil fuels. Nuclear energy, which produces no green house gases and no air pollution, should be a leading candidate. How nuclear energy, based on thorium rather than uranium, could be an acceptable solution is discussed. Thorium can be used both to produce energy or to destroy nuclear waste. The thorium conference, organized by iThEC at CERN in October 2013, has shown that thorium is seriously considered by developing countries as a key element of their energy strategy. However, developed countries do not seem to move in that direction, while global cooperation is highly desirable in this domain. As thorium is not fissile, an elegant option is to use a proton accelerator to drive an “Accelerator Driven System (ADS)”, as suggested by Nobel Prize laureate Carlo Rubbia. Therefore, the accelerator community has an important challenge to meet: provide the required proton beam for ADS.
	Slides FRIOB03 [20.039 MB]

Paper

Title

Other Keywords

Page

MOPP010

Low Charge State Laser Ion Source for the EBIS Injector

ion, injection, laser, electron

64

M. Okamura, J.G. Alessi, E.N. Beebe, T. Kanesue, C.J. Liaw, V. LoDestro, A.I. Pikin, D. Raparia, J. Ritter
BNL, Upton, Long Island, New York, USA
Y. Fuwa, S. Ikeda, M. Kumaki
RIKEN, Saitama, Japan

Funding: NASA
In March 2014, we have successfully commissioned a newly designed low charge high brightness laser ion source (LIS) which delivers various singly charged heavy ions to the electron beam ion source (EBIS) at Brookhaven National Laboratory. Now the LIS is used at routine operation of the RHIC-AGS accelerator complex and is providing stable less-contaminated beams. The laser power density was optimized to provide singly charged ions with low material consumption rate. The nominal laser energy on the target is around 500 mJ with 1064 nm Nd:YAG of the wave length. The induced plasma by the laser is transported through a 3 m pipe to stretch ion beam pulse length to match the EBIS’s requirement and the degradation of the beam current caused by the long drift section of the pipe can be compensated by a longitudinal magnetic filed induced by a coil surrounding the pipe. We also employed a twin laser system to extend the beam width further. At the conference, we will discuss the effect of the new LIS on the various accelerated beams through the EBIS, RFQ and IH-linac.

MOPP011

Reliability and Intensity Upgrade for 200 MeV Linac at Brookhaven National Laboratory

linac, detector, operation, ion

67

D. Raparia, J.G. Alessi, B. Briscoe, D.M. Gassner, O. Gould, T. Lehn, V. Lo Destro, J. Ritter, W. Shaffer, A. Zelenski
BNL, Upton, Long Island, New York, USA

Brookhaven 200 MeV H⁻ linac has been operating for last 44 years and providing beam to nuclear physics program and isotope program. Two upgrade programs are in progress to make machine more reliable and to double the intensity. This paper will discuss in detail these upgrade programs.

MOPP038

Longitudinal Bunch Profile Monitoring at the ESS Linac

linac, simulation, proton, neutron

143

I. Dolenc Kittelmann, B. Cheymol
ESS, Lund, Sweden

The European Spallation Source (ESS), which is currently under construction, will be a neutron source based on 5MW, 2GeV proton linac. This high intensity linac will among other beam instrumentation require longitudinal bunch profile monitors. These shall be used during the commissioning phase and start-up periods for beam dynamics optimization and beam loss reduction. The paper focuses on the preliminary studies concerning the longitudinal bunch profile monitoring at the ESS linac.

MOPP076

Construction of an Accelerator-based BNCT Facility at yhe Ibaraki Neutron Medical Research Center

neutron, linac, rfq, klystron

230

M. Yoshioka, H. Kobayashi, T. Kurihara, S.-I. Kurokawa, H. Matsumoto, N. Matsumoto
KEK, Ibaraki, Japan
T. Hashirano, T. Sugano
MHI, Hiroshima, Japan
F. Hiraga
Hokkaido University, Sapporo, Japan
H. Kumada, Su. Tanaka
Tsukuba University, Graduate School of Comprehensive Human Sciences, Ibaraki, Japan
A. Matsumura, H. Sakurai
Tsukuba University, Ibaraki, Japan
N. Nagura, T. Ohba
Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan
T.N. Nakamoto, T. Zagar
Cosylab, Ljubljana, Slovenia
T. Nakamura
JAEA, Ibaraki-ken, Japan
T. Ouchi
ATOX, Ibaraki, Japan

An accelerator-based BNCT (Boron Neutron Capture Therapy) facility is being constructed at the Ibaraki Neutron Medical Research Center. It consists of a proton linac of 80kW beam power with 8 MeV energy and 10mA average current, a beryllium target, and a moderator system to provide an epi-thermal neutron flux enough for patient treatment. The technology choices for this present system were driven by the need to site the facility in a hospital and where low residual activity is essential. The maximum neutron energy produced from an 8 MeV-proton is 6 MeV, which is below the threshold energy of the main nuclear reactions which produce radioactive products. The down side of this technology choice is that it produces a high density heat load on the target so that cooling and hydrogen aniti-blistering amelioration prevent sever challenges requiring successful R&D progress. The latest design of the target and moderator system shows that a flux of 4×10⁹ epi-thermal neutrons / cm² / sec can be obtained. This is much higher than the flux from the existing nuclear reactor based BNCT facility at JAEA ( JRR-4).

MOPP077

Electron-Driven Positron Capture Simulation for ILC

positron, electron, linac, booster

233

Y. Seimiya, M. Kuriki
HU/AdSM, Higashi-Hiroshima, Japan
S. Kashiwagi
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
T. Okugi, T. Omori, M. Satoh, J. Urakawa
KEK, Ibaraki, Japan
T. Takahashi
Hiroshima University, Graduate School of Science, Higashi-Hiroshima, Japan

ILC (International Linear Collider) is a next high-energy physics project to study the Higgs property as detail as possible and new phenomena beyond standard model. In ILC, the positron beam is produced by converting gamma rays from undulator radiations. To obtain gamma rays as undulator radiation, the electron beam for collision (150 GeV or more) is used. This positron generation scheme is a totally new approach. From project point of view, it is desirable to have a technical backup as a replacement of the undulator scheme. We propose an ILC positron source based on the conventional electron driven scheme. In this scheme, positron beam is generated from electromagnetic shower in a heavy target material where electron beam is injected. By manipulating the beam time structure to relax the heat load on the production target, the scheme can be feasible technically. In this study, positron capture in the electron driven scheme is simulated from the positron production to the positron damping ring, to demonstrate that an enough amount of positron can be generated and captured with a controllable heat load on the target.

Poster MOPP077 [0.879 MB]

MOPP088

MUNES a Compact Neutron Source for BNCT and Radioactive Wastes Characterization

neutron, rfq, proton, quadrupole

261

A. Pisent, P. Colautti, E. Fagotti
INFN/LNL, Legnaro (PD), Italy

At INFN LNL (Legnaro Italy) it has been built a high intensity Radio Frequency Quadrupole (RFQ) structure, able to produce a 5 MeV proton beam of 30 mA. Coupled with a Be target such a beam can generate a neutron flux of 10¹⁴ n/s, with a spectrum centered in the MeV region (that has been recently characterized in detail at LNL accelerators). This neutron flux can be moderated to generate a thermal or epithermal source for BNCT with very little contamination of energetic form energetic neutron and gamma. Since the approval of MUNES project (in 2012) the high technology issues related to a compact neutron source to be installed in an Hospital environment have been faced. In particular for the powering of the accelerating structure an innovative system, completely based on solid state amplifiers, has been developed and ordered to industry. An outline of MUNES design and the status of the project will be given in the paper.

MOPP109

Ion Beam Acceleration in Neutron Tube

electron, ion, neutron, space-charge

310

V.I. Rashchikov
MEPhI, Moscow, Russia
A.S. Plastun
ITEP, Moscow, Russia

Deuteron beam acceleration in ion-optic system of gas-filled neutron tubes was investigated. PIC code SUMA "*" used for computer simulation of ionization and knock on processes and there influence on deuteron beam parameters. When deuteron and ionized particles own space charge forces become the same order of magnitude as external one, virtual cathode may occurs. It is happened because of injected from ion source deuterons cannot overcome their own space charge potential wall and move in transverse direction. However, electrons, produced by ionization, are trapped within the deuteron beam space charge potential wall and decrease it significantly. Thus, space charge neutralization of deuteron beams by electrons, may considerably increase target current and, as a result, output neutron flow. Moreover, own longitudinal electric field rise near the target leads to reduction of accelerating electrode – target potential wall, which was made to prevent knock on emission from the target. As a result, additional knocked on electrons may appear in the region and should be taken into account. The data obtained were compared with experimental results.
* A.N. Didenko, V.I. Rashchikov, V.E. Fortov, Technical Physics, Vol. 56, No. 10,pp. 1535–1538, 2011

MOPP138

Fabrication and Measurements of 500 MHz Double Spoke Cavity

cavity, electron, simulation, radiation

385

H. Park, J.R. Delayen
JLab, Newport News, Virginia, USA
J.R. Delayen, C.S. Hopper, H. Park
ODU, Norfolk, Virginia, USA

The 500 MHz double spoke cavity has been designed for a high velocity application such as a compact electron accelerator at Center for Accelerator Science at Old Dominion University and is being built at Jefferson Lab. The geometry specific to the double spoke cavity requires a variety of tooling and fixtures. Also a number of joints are expected to make it difficult to maintain the geometric deviation from the design minimal. This paper will report the fabrication technique, resulting tolerance from the design, and comparison between the measurements and simulations.

Poster MOPP138 [2.144 MB]

TUPP003

4 K Alignment of Superconducting Quarter-Wave Cavities and 9 T Solenoids in the ATLAS Intensity Upgrade Cryomodule

cryomodule, solenoid, alignment, cavity

443

S.H. Kim, Z.A. Conway, W.G. Jansma, M. Kedzie, M.P. Kelly, P.N. Ostroumov
ANL, Argonne, Illinois, USA

Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under contract number DE-AC02-06CH11357.
The superconducting cavities and, especially, the magnets in high intensity ion linacs need to be aligned to the beam with typical transverse tolerances of 0.25 mm and 0.1 degrees at temperatures of 1.8 – 4.5 K. This is necessary to limit the emittance growth and minimize the beam losses. A new cryomodule with 7 superconducting quarter-wave resonators and 4 superconducting solenoids has been installed and is now operated at the Argonne Tandem Linear Accelerator System (ATLAS). We developed the techniques necessary to assemble the superconducting components in this cryomodule at room temperature so that they are aligned to the beam axis at 4.5 K. We achieved transverse alignment tolerances of <0.2 mm RMS. In this paper, we will present the details of the alignment hardware, procedures and results.

Slides TUPP003 [0.834 MB]

TUPP004

An In-flight Radioactive Ion Separator Design for the ATLAS Facility

dipole, ion, quadrupole, simulation

446

B. Mustapha, B. Back, C.R. Hoffman, B.P. Kay, J.A. Nolen, P.N. Ostroumov
ANL, Argonne, USA

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
An in-flight radioactive beam separator, named AIRIS, is being designed to enhance the radioactive beam capabilities of the ATLAS facility at Argonne. In order to serve all the experimental areas while maintaining the stable beam capabilities, the separator design is of broadband type. This design allows the selected radioactive beam to come back on the ATLAS beam line while stable beams continue on the same straight line with the separator turned off. The separation is performed in two steps, the first is magnetic in a chicane made of four magnets and four multipoles, while the second uses an rf sweeper taking advantage of the time separation between the beam of interest and potential contaminants including the primary beam tail. We will report on the progress of the AIRIS design effort with special emphasis on the performance of the rf sweeper.

TUPP015

Status on Airix Restart

electron, induction, timing, operation

462

A. Georges, J. Beaubernard, V. Bernigaud, L. Buche, Y. Collet, S. Combacon, B. Gouin, G. Grandpierre, J.K. Kranzmann, L. Magnin, R. Nicolas, D. Pierre, F. Poulet, Y. Tailleur, J-L. Verstraete, J. Magnan
CEA, Pontfaverger-Moronvilliers, France

The Airix accelerator has been moved from Moronvilliers to Valduc to be part of the EPURE facility. Airix has been refurbished and restarted. This paper presents the first results and quantification of performances at its new location.
*M.Mouillet et al., “First results of AIRIX induction accelerator”,XXth LINAC cf.,p.491(2000)
**H.Dzitko et al., "operationnal efficiency of Airix accelerator since its commissioning",IPAC2012,p.4017

TUPP022

RF Tuning of a S-band Hybrid Buncher for Injector Upgrade of LINAC II at DESY

linac, electron, simulation, experiment

478

Y.C. Nie, M. Hüning, C. Liebig, M. Schmitz
DESY, Hamburg, Germany

LINACII at DESY currently provides 450 MeV electrons for the synchrotron radiation source PETRAIII. The injector upgrade of it aims to improve its reliability and mitigate the radiological activation due to electron losses at hundreds of MeV. Therefore, a 2.998 GHz hybrid buncher has been developed and will be installed in between a pre-buncher and LINAC II. It comprises a 1-cell standing-wave (SW) section for rapid acceleration and a 13-cells travelling-wave (TW) section for further bunching and acceleration. This paper focuses on its rf tuning procedure. The tuning strategy combines a non-resonant bead-pull measurement of complex electric field and a linear model for local reflection coefficient calculation. The tuning result is satisfying. Field unflatness of the TW section has been improved from ±9% to ±4%, and field in the SW section has been enhanced significantly. By using ASTRA simulation, it has been verified that the residual detuning of the structure is acceptable in view of beam dynamics performance.

TUPP083

Design and Analysis of Slow Tuner in the Superconducting Cavity of RISP

cavity, superconducting-cavity, niobium, SRF

616

M.O. Hyun, H.C. Jung, H.J. Kim
IBS, Daejeon, Republic of Korea

Funding: This work was supported by the Rare Isotope Science Project of Institute of Basic Science funded by the Ministry of Science, ICT and Future Planning and National Research Foundation.
Superconducting cavity is one of the most complex systems from the view of mechanical engineering, which is installed and operated in the superconducting linear accelerator. In order to operate SC cavity properly and precisely, superconducting cavity needs many sub-systems, including power coupler for applying RF power inside cavity, and liquid helium jacket for cooling cavity until reaching to the superconducting conditions. And, also cavity needs frequency tuning system for adjusting operating frequency when RF frequency of cavity is changed with outer disturbances such as liquid helium fluctuation, mechanical deformation due to vacuum condition of cavity. Generally, this tuning system is called as a tuner. There are two types of tuner, one is slow tuner which operates with motor, and the other is fast tuner which operates with piezo-electric actuator. This paper describes about design process and analysis results about slow tuner.

TUPP088

The Fabrication of the β=0.12 HWR at RISP

niobium, cavity, vacuum, electron

628

G.-T. Park, H.J. Cha, Y. Jung, H. Kim, W.K. Kim
IBS, Daejeon, Republic of Korea

At RISP, the superconducting cavities have been developed to construct RAON, the heavy ion accelerator. Among the cavities, the fabrication of the QWR (Quarter wave resonator) and the HWR (Half wave resonator)are complete. The detailed fabrication processes including material inspection, forming, the electron beam welding, and the clamp up test are described.

TUPP100

Operation Of The Versatile Accelerator Driving the Low Power ADS GUINEVERE at SCK•CEN

neutron, operation, ion, ion-source

659

M.A. Baylac, A. Billebaud, P. Boge, D. Bondoux, J. Bouvier, S. Chabod, G. Dargaud, E. Froidefond, E. Labussière, R. Micoud, S. Rey
LPSC, Grenoble Cedex, France
A. Kochetkov, J. Mertens, F. Van Gestel, C. Van Grieken, B. Van Houdt, G. Vittiglio
SCK•CEN, Mol, Belgium
F.R. Lecolley, J.L. Lecouey, G. Lehaut, N. Marie-Nourry
CNRS/IN2P3/LPC CAEN, Caen, France

GUINEVERE provides a low power accelerator driven system (ADS) to investigate on-line reactivity monitoring and operational procedures of an ADS. It consists of a versatile neutron source, GENEPI-3C, driving the fast sub-critical core, VENUS-F, in SCK•CEN (Belgium). GENEPI-3C is an electrostatic accelerator generating 14 MeV neutrons by bombarding a 250 keV deuteron beam onto a tritium target located within the reactor core. This accelerator produces alternatively continuous beam (up to 1 mA DC), possibly chopped with fast and adjustable interruptions, or short and intense deuteron bunches (~25 mA peak, 1 μs). This paper presents the facility and assesses the 2 years of coupled operation of the accelerator to the reactor.

Slides TUPP100 [0.969 MB]

TUPP101

Vertical Electro-Polishing of Nb Single-Cell Cavity Using Cathode with Variable-Geometry Wings and Its Results of Vertical Test

cavity, cathode, power-supply, experiment

662

K.N. Nii, V. Chouhan, Y.I. Ida, T.Y. Yamaguchi
MGH, Hyogo-ken, Japan
P. Carbonnier, F. Éozénou, C. Servouin
CEA/DSM/IRFU, France
H. Hayano, S. Kato, H. Monjushiro, T. Saeki, M. Sawabe
KEK, Ibaraki, Japan
K. Ishimi
MGI, Chiba, Japan
C. Madec, L. Maurice
CEA/IRFU, Gif-sur-Yvette, France

Marui Galvanizing Co. Ltd. has been studying Vertical Electro-Polishing (VEP) on Nb superconducting accelerator cavity with the goal of mass-production and cost-reduction of Electro-Polishing (EP) process in collaboration with KEK and CEA Saclay. And we invented variable-geometry wings cathode for VEP process to get uniform distributions of both electric current and EP solution flow. Using this cathode, we performed various tests of VEP with Nb single-cell cavities. In this article, we will report the results of vertical test of Nb single-cell cavity which is VEP’ed by cathode with variable-geometry wings.

WEIOB02

SARAF Phase-I Proton / Deuteron Linac Beam Operation Status

operation, rfq, proton, neutron

770

A. Kreisel, A. Arenshtam, Y. Ben Aliz, D. Berkovits, Y. Buzaglo, O. Dudovich, Y. Eisen, I. Eliyahu, G. Feinberg, I. Fishman, I.G. Gertz, A. Grin, S. Halfon, Y.F. Haruvy, T. Hirsch, D. Hirschmann, Z. Horvitz, B. Kaizer, D. Kijel, J. Luner, I. Mor, J. Rodnizki, G. Shimel, A. Shor, I. Silverman, D. Vartsky, L. Weissman, E. Zemach
Soreq NRC, Yavne, Israel

SARAF Phase-I linac is the first accelerator to demonstrate acceleration of variable energy 2 mA CW proton beam. Such intense beam is used in SARAF Phase-I to irradiate a liquid lithium jet target for nuclear astrophysics studies. Several improvements were necessary to allow beam operation with such high current. The improvements include a DC bias that was introduced on the cavity RF coupler to reduce coupler heating. A new slow chopper was commissioned to enable increase the current by increasing the duty cycle with fewer changes in the beam optics. A beam dump was developed to allow beam studies of a 2 mA CW proton beam. The beam dump is based on tungsten pins which distributes, by radiation, the high beam power over a large area which is then easily water cooled. While most of beam tuning is done using a low intensity pilot beam, some nondestructive methods were studied to monitor the high intensity beam. These include a current transformer and a residual gas monitor (RGM) to monitor beam transverse distribution. Additional valuable information about the beam current and energy is gained from measurements of the nuclear reaction products of the proton on lithium targets.

Slides WEIOB02 [3.027 MB]

WEIOB03

Status of RAON Heavy Ion Accelerator Project

ion, rfq, cavity, linac

775

D. Jeon, H.J. Kim
IBS, Daejeon, Republic of Korea

Funding: This work was supported by the Institute for Basic Science funded by the Ministry of Science, ICT and Future Planning (MSIP) and the NRF of Korea under Contract 2013M7A1A1075764.
Construction of the RAON heavy ion accelerator facility is under way in Korea to build the In-flight Fragment (IF) and Isotope Separation On-Line (ISOL) facilities to support cutting-edge researches in various science fields. At present prototyping of major components are proceeding including 28 GHz ECR ion source, RFQ, superconducting cavities, magnets and cryomodules. Superconducting magnets of 28 GHz ECR ion source are fabricated and tested. First article of prototype superconducting cavities are delivered that were fabricated through domestic vendors. Prototype HTS quadrupole is under development. Progress report of the RAON accelerator systems is presented.

Slides WEIOB03 [6.228 MB]

THPP007

Uniform Current Density for BLIP Target at Brookhaven 200 MeV Linac

linac, octupole, dipole, isotope-production

850

D. Raparia, B. Briscoe, P. Cerniglia, R. Connolly, C. Cullen, D.M. Gassner, R.L. Hulsart, R.F. Lambiase, V. Lo Destro, L.F. Mausner, R.J. Michnoff, P. Thieberger, M. Wilinski
BNL, Upton, Long Island, New York, USA

Bulk of the beam from the linac is used for Brookhaven linac isotope producer (BLIP). The average current from the linac is up 125 uA. At this current BLIP has several target failures and yield uncertainty due to partially melted target salt. To reduce current density, we have tried octupoles in the past but did not produce uniform beam as calculated due to the x-y coupling present in the linac. A beam painting scheme with help of one x and y steers with 90 phase leg at 5 kHz will provide desire current density at the target. This paper discuss beam optics of the blip transport line and beam footprint on the target with given constrains.

THPP032

Magnetic Characterization of Fast-Pulsed Quadrupole Magnets for Linac4

quadrupole, linac, flattop, power-supply

909

S. Kasaei, M.C.L. Buzio, O. Crettiez, V. Della Selva, L. Fiscarelli, J. Garcia Perez, J.-B. Lallement
CERN, Geneva, Switzerland

Linac4, currently being built at CERN, includes 24 quadrupole magnets characterized by narrow apertures and fast excitation cycles which make accurate magnetic measurements challenging. This paper describes the method used for the measurement, which is a combination of techniques based on stretched wire, rotating and fixed search coils. We show how these different instruments can be used in a complementary way to derive information on different aspects of the magnetic behaviour, such as the impact of hysteresis and dynamic eddy current effects. We summarize the results of the series measurement campaign, which include field strength, harmonic components, and the offset and orientation of the magnetic axis. Finally, we discuss the relevance of these measurements as their impact to the operation of the linac.

THPP079

Prototyping Progress of SSR1 Single Spoke Resonator for RAON

cavity, simulation, vacuum, heavy-ion

1

H.J. Cha, M.O. Hyun, D. Jeon, H.C. Jung, H.J. Kim
IBS, Daejeon, Republic of Korea

The fabrication of prototypes for four different types of superconducting cavities (QWR, HWR, SSR1, and SSR2) for the Korean heavy ion accelerator, “RAON” is in progress. In this presentation, we report the current status of the SSR1 cavity (β=0.3 and f=325 MHz) prototype fabrication based on the technical designs. The issues when forming the niobium cavities such as pressing, machining, electron beam welding are reviewed. The RF testing for the prototypes, which will be done in near future, is also discussed.

THPP098

Vertical Electropolishing of Nb Coupon Cavity and Surface Study of the Coupon Samples

cathode, cavity, experiment, superconducting-RF

1080

V. Chouhan, Y.I. Ida, K.N. Nii, T.Y. Yamaguchi
MGH, Hyogo-ken, Japan
H. Hayano, S. Kato, H. Monjushiro, T. Saeki, M. Sawabe
KEK, Ibaraki, Japan
K. Ishimi
MGI, Chiba, Japan

We have been carrying out vertical electropolishing (VEP) of 1.3 GHz Nb cavities for the ILC for 2 years. In this article we present VEP of a single cell Nb coupon cavity containing 6 Nb disk type coupons located at beam pipes, irises and equator positions of the cavity. VEP experiments were performed using our special ninja-cathode newly developed and a straight rod cathode in order to observe and compare the homogeneity of electropolishing (EP) and surface quality on the entire surface of the single cell cavity. EP current was measured for the individual coupons under different EP conditions in order to study the EP phenomenon on the different positions of the cavity. The surfaces of the coupons were analyzed by x-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDX). This article describes VEP and surface analysis results in detail.

THPP130

Development of FPGA-based Predistortion-type Linearization Algorithms for Klystrons within Digital LLRF Control Systems for ILC-like Electron Accelerators

klystron, controls, LLRF, FPGA

1162

M. Omet
Sokendai, Ibaraki, Japan
B. Chase, P. Varghese
Fermilab, Batavia, Illinois, USA
T. Matsumoto, S. Michizono, T. Miura, F. Qiu
KEK, Ibaraki, Japan

Two different kinds of predistortion-type linearization algorithms have been implemented and compared on an FPGA within the digital LLRF control system the Advanced Superconducting Test Facility (ASTA) at the Fermi National Accelerator Laboratory (FNAL). The algorithms are based on 2nd order polynomial functions and lookup tables with interpolation by which complex correction factors are obtained. The algorithms were tested in an actual setup including a 5 MW klystron and a superconducting 9-cell TESLA-type cavity at ASTA. By this a proof of concept was demonstrated.

Poster THPP130 [2.411 MB]

THPP137

Present Status of the 3 MeV Proton Linac at Tsinghua University

linac, rfq, proton, status

1182

Q.Z. Xing, C. Cheng, C.T. Du, L. Du, T. Du, X. Guan, C. Jiang, C.-X. Tang, X.W. Wang, H.Y. Zhang, S.X. Zheng
TUB, Beijing, People's Republic of China
W.Q. Guan, Y. He, J. Li
NUCTECH, Beijing, People's Republic of China
B.C. Wang
NINT, Xi'an, People's Republic of China

We present, in this paper, the present status of the 3 MeV high current proton Linac for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University. The ECR ion source produces 50 keV proton beam which is accelerated to 3 MeV by the downstream RFQ accelerator. The RFQ accelerator has been conditioned to 50 Hz/500 μs with the input power of 442 kW. Proton beam with the peak current of 30 mA, pulse length of 100 μs and repetition rate of 50 Hz has been delivered to the Beryllium target to produce the neutron since July 2013. The status of the development of the Drift Tube Linac is also presented in this paper. The beam energy will be enhanced to 13 MeV after the DTL is ready in 2015.

FRIOB03

Prospects for Accelerator-Driven Thorium Systems

neutron, proton, cyclotron, experiment

1213

J.-P. Revol
iThEC, Geneva, Switzerland

To meet the tremendous world energy needs, systematic R&D has to be pursued to replace fossil fuels. Nuclear energy, which produces no green house gases and no air pollution, should be a leading candidate. How nuclear energy, based on thorium rather than uranium, could be an acceptable solution is discussed. Thorium can be used both to produce energy or to destroy nuclear waste. The thorium conference, organized by iThEC at CERN in October 2013, has shown that thorium is seriously considered by developing countries as a key element of their energy strategy. However, developed countries do not seem to move in that direction, while global cooperation is highly desirable in this domain. As thorium is not fissile, an elegant option is to use a proton accelerator to drive an “Accelerator Driven System (ADS)”, as suggested by Nobel Prize laureate Carlo Rubbia. Therefore, the accelerator community has an important challenge to meet: provide the required proton beam for ADS.

Slides FRIOB03 [20.039 MB]