Keyword: vacuum
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SUPB035 RF Photoinjector and Radiating Structure for High-power THz Radiation Source radiation, coupling, electron, impedance 86
 
  • S.M. Polozov, T.V. Bondarenko
    MEPhI, Moscow, Russia
  • Y.A. Bashmakov
    LPI, Moscow, Russia
 
  Sources of high-power electromagnetic radiation in THz band are becoming promising as a new method of a low activation introscopy. Research and development of accelerating RF photoinjector and radiating system for THz radiation source are reported. The photoinjector is based on disk loaded waveguide (DLW). Two different designs of accelerating structures were modeled: widespread 1.6 cell of DLW structure and travelling wave resonator structure. The resonant models of these structures and the structures with power ports were designed. Electrodynamics characteristics and electric field distribution for all models were acquired. Results of picoseconds photoelectron beam dynamics in modeled structures are reported. Design of decelerating structures exciting Cherenkov radiation are based on corrugated metal channel and metal channel coated with dielectric. Analysis of radiation intensity and frequency band are presented.  
 
MOPB011 Photoinjector of the EBTF/CLARA Facility at Daresbury gun, laser, cavity, electron 192
 
  • B.L. Militsyn, D. Angal-Kalinin, C. Hill, S.P. Jamison, J.K. Jones, J.W. McKenzie, K.J. Middleman, B.J.A. Shepherd, R.J. Smith, R. Valizadeh, A.E. Wheelhouse
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • N. Bliss, M.D. Roper
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
 
  A description is given of a photoinjector designed for Compact Linear Advanced Research Accelerator (CLARA) and Electron Beam Test Facility (EBTF), which will eventually be used to drive a compact FEL. The photoinjector is based on a 2.5 cell S-band photocathode RF gun operating with a copper photocathode and driven by a third harmonic of Ti: Sapphire laser (266 nm) installed in dedicated thermally stabilized room. The injector will be operated with laser pulses with an energy of up to 2 mJ, a pulse duration of 100 fs and initially a repetition rate of 10 Hz, with the aim of increasing this eventually to 400 Hz. At a field gradient of 100 MV/m provided by a 10 MW klystron the gun is expected to deliver beam pulses with energy of up to 6 MeV. Duration and emittance of electron bunches essentially depend on the bunch charge and vary from 0.1 ps at 20 pC to 5 ps at 200 pC and from 0.2 to 2 mm mrad respectively. Additional compression of the electron bunches will be provided with a velocity bunching scheme. For thermal stability the low energy part of the injector is mounted on an artificial granite support.  
 
MOPB017 Integration of the European XFEL Accelerating Modules cavity, controls, linac, HOM 207
 
  • E. Vogel, S. Barbanotti, J. Branlard, H. Brueck, S. Choroba, L. Hagge, K. Jensch, V.V. Katalev, D. Kostin, D. Käfer, L. Lilje, A. Matheisen, W.-D. Möller, D. Nölle, B. Petersen, J. Prenting, D. Reschke, H. Schlarb, M. Schmökel, J.K. Sekutowicz, W. Singer, H. Weise
    DESY, Hamburg, Germany
  • J. Świerbleski, P.B. Borowiec
    IFJ-PAN, Kraków, Poland
  • S. Berry, O. Napoly, B. Visentin
    CEA/DSM/IRFU, France
  • A. Bosotti, P. Michelato
    INFN/LASA, Segrate (MI), Italy
  • W. Kaabi
    LAL, Orsay, France
  • C. Madec
    CEA/IRFU, Gif-sur-Yvette, France
  • E.P. Plawski
    NCBJ, Świerk/Otwock, Poland
  • F. Toral
    CIEMAT, Madrid, Spain
 
  The production of the 103 superconducting accelerating modules for the European XFEL is an international effort. Institutes and companies from seven different countries (China, France, Germany, Italy, Poland, Russia and Spain), organized in 12 different work packages contribute with parts, capacity for work and facilities to the production of the modules. Currently the series production of the individual parts started or is approaching. Personnel are trained for the assembly and testing of parts and as well for the complete modules. Here we present an overview and the status of all these activities.  
 
MOPB022 RF Characteristic Studies on the Whole Accelerating Structure for the BEPCII Linear Accelerator linac, simulation, impedance, electromagnetic-fields 219
 
  • S. Pei, M. Hou, X. Li, J.R. Zhang
    IHEP, Beijing, People's Republic of China
  • B.L. Wang
    SINAP, Shanghai, People's Republic of China
 
  An accelerating structure is one device to boost the particle energy. 2856 MHz 3 m long travelling wave disk-loaded accelerating structure is applied in BEPCII linac, its RF characteristics are mainly determined by the 84 regular cells located between the input and output couplers. Input and output couplers need to be included when the whole structure RF characteristics are simulated before fabrication; otherwise it would be difficult to obtain the travelling wave fields excited in the whole structure. If the real 3D couplers are modelled during the design process, a large amount of computer resources and time need to be used. However, if the redesigned azimuth symmetric coupler is used to replace the real 3D one during the simulation process, much less computer resources and time are required. With this method proposed here, the simulation results agree well with the theoretically calculated and experimentally measured ones.
*peisl@ihep.ac.cn
 
 
MOPB030 Performance of First C100 Cryomodules for the CEBAF 12 GeV Upgrade Project cryomodule, cavity, linac, instrumentation 237
 
  • M.A. Drury, A. Burrill, G.K. Davis, J. Hogan, L.K. King, F. Marhauser, H. Park, J.P. Preble, C.E. Reece, A.V. Reilly, R.A. Rimmer, H. Wang, M. Wiseman
    JLAB, Newport News, Virginia, USA
 
  Funding: This manuscript has been authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
The Thomas Jefferson National Accelerator Facility is currently engaged in the 12 GeV Upgrade Project. The goal of the project is a doubling of the available beam energy of CEBAF from 6 GeV to 12 GeV. This increase in beam energy will be due primarily to the construction and installation of ten “C100” cryomodules in the CEBAF linacs. The C100 cryomodules are designed to deliver an average 108 MV each from a string of eight seven-cell, electropolished superconducting RF cavities operating at an average accelerating gradient of 19.2 MV/m. The new cryomodules fit in the same available linac space as the original CEBAF 20 MV cryomodules. Cryomodule production started in September 2010. Initial acceptance testing started in June 2011. The first two C100 cryomodules were installed and tested from August 2011 through October 2011, and successfully operated during the last period of the CEBAF 6 GeV era, which ended in May 2012. This paper will present the results of acceptance testing and commissioning of the C100 style cryomodules to date.
 
 
MOPB033 High Power Coupler Test for TRIUMF E-linac SC Cavities linac, TRIUMF, electron, monitoring 246
 
  • A.K. Mitra, Z.T. Ang, S. Calic, P.R. Harmer, S.R. Koscielniak, R.E. Laxdal, W.R. Rawnsley, R.W. Shanks
    TRIUMF, Vancouver, Canada
 
  TRIUMF has been funded to build an electron linac with a final energy of 50 MeV and 500 kW beam power using TESLA type 9 cell superconducting cavities operating at 1.3 GHz at 2 Kelvin. The e-linac consists of an electron gun, buncher cavity, injector cryomodule, and two main-linac cryomodules. The injector module has one 9-cell cavity whereas each of the accelerating main-linac cryomodules contains two 9-cell cavities. It is scheduled to install the injector and one main accelerating cryomodule by 2014. Six power couplers, each rated for 60 kW cw, have been procured for three cavities. The injector cryomodule will be fed by a 30 kW cw inductive Output Tube (IOT) and the accelerating cryomodule will be powered by a 290 kW cw klystron. In order to install the power couplers in the cavities, they are to be assembled and conditioned with high power rf source. A power coupler test station has been built and tests of two power couplers have began. A 30 kW IOT has been commissioned to full output power and it will be used for the power coupler test. In this paper, test results of the rf conditioning of the power couplers under pulse and cw mode will be described.  
 
MOPB069 Study of HPR Created Oxide Layer at Nb Surfaces SRF, cavity, electron, ion 336
 
  • P.V. Tyagi
    Sokendai, Ibaraki, Japan
  • H. Hayano, S. Kato, T. Saeki, M. Sawabe
    KEK, Ibaraki, Japan
 
  The performance of superconducting radio frequency (SRF) niobium (Nb) cavities strongly depends on final surface condition. Therefore the surface preparation of these SRF cavities often becomes critical. The preparation of surface includes two steps; surface chemistry (in order to get a smooth surface) and cleaning/rinsing (in order to remove contaminants left after the surface chemistry). As high pressure rinsing (HPR) with ultra pure water (UPW) is most commonly used surface cleaning method after the surface chemistry, it's very interesting to characterize the Nb surfaces after HPR. Results of our surface characterization done by XPS (x-ray photoelectron spectroscopy) with depth profiling show the presence of a thicker oxide surface characterization results show the presence of a thicker oxide layer at Nb surface as an outcome of HPR. In this article, we report the production of oxide layer (FWHM thickness) based on different conditions such as the pressures and doses.  
 
MOPB071 Process Developments for Superconducting RF Low Beta Resonators for the ReA3 LINAC and Facility for Rare Isotope Beams cavity, controls, SRF, linac 342
 
  • L. Popielarski, C. Compton, L.J. Dubbs, K. Elliott, A. Facco, L.L. Harle, I.M. Malloch, R. Oweiss, J.P. Ozelis, J. Popielarski, K. Saito
    FRIB, East Lansing, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE SC0000661.
The Facility for Rare Isotope Beams (FRIB) will utilize over 330 superconducting radio frequency (SRF) low beta cavities for its heavy ion driver linac. The SRF department will process and test all cavities prior to string assembly in the cleanroom. The baseline cavity surface and bulk niobium processing procedures have been established. The methods are being optimized for production process rate benchmarking. Additional processes are being developed to increase flexibility and reduce technical risks. This paper will describe procedure developments and experimental results. Topics include high temperature heat treatment for hydrogen degassing, selective chemical etching for cavity frequency tuning, low-temperature bake out and process quality control.
 
 
MOPB074 Thermo-Mechanical Simulations of the Frequency Tuning Plunger for the IFMIF Half-Wave Resonator niobium, cavity, simulation, cryomodule 351
 
  • N. Bazin, P. Bosland, S. Chel, G. Devanz, N. Grouas, P. Hardy, J. Migne, F. Orsini, F. Peauger
    CEA/DSM/IRFU, France
 
  In the framework of the International Fusion Materials Irradiation Facility (IFMIF), a superconducting option has been chosen for the 5 MeV RF Linac of the first phase of the project (EVEDA), based on a cryomodule composed of 8 HWRs, 8 RF couplers and 8 Solenoid packages. The frequency tuning system of the IFMIF HWR is an innovated system based on a capacitive plunger installed in the electric field region allowing a large tuning range. Following the cold test results obtained on HWR equipped with the first design of plunger in 2011*, it was decided to develop a new design of a fully-niobium plunger. The paper will present the development of the new plunger concepts and the thermo-mechanical simulations. For the mechanical simulations, the aim is to sufficiently deform the plunger to tune the cavity while staying in the elastic range of the niobium material. For the thermal simulations, all the non-linear properties of the materials and the effects of the RF fields are taken into account: thermal conductivity and surface resistance are depending on the temperature, RF fields computed with dedicated software are leading to thermal dissipations in the materials and the vacuum seal.
* F. Orsini et al., “Vertical tests preliminary results of the IFMIF cavity prototypes and cryomodule development”, SRF 2011, Chigaco, USA
 
 
MOPB087 S-Band Loads for SLAC Linac linac, klystron, plasma, insertion 378
 
  • A. Krasnykh, F.-J. Decker
    SLAC, Menlo Park, California, USA
  • R.W. LeClair
    INTA, Santa Clara, USA
 
  Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515 and SBIR grant number DE-SC0007661
The S-Band loads on the current SLAC linac RF system were designed, in some cases, 40+ years ago to terminate 2-3 MW peak power into a thin layer of coated Kanthal material as the high power absorber [1]. The technology of the load design was based on a flame-sprayed Kanthal wire method onto a base material. During SLAC linac upgrades, the 24 MW peak klystrons were replaced by 5045 klystrons with 65+ MW peak output power. Additionally, SLED cavities were introduced and as a result, the peak power in the current RF setup has increased up to 240 MW peak. The problem of reliable RF peak power termination and RF load lifetime required a careful study and adequate solution. Results of our studies and three designs of S-Band RF load for the present SLAC RF linac system is discussed. These designs are based on the use of low conductivity materials.
[1] “The Stanford Two-Mile Accelerator”, p. 376-381, R. B. Neal, General Editor, 1968, W. A. Benjamin, Inc., NY Amsterdam
 
 
MOPB088 Fabrication Tests for IMP 162.5 MHz RFQ rfq, cavity, gun, linac 381
 
  • B. Zhang
    IMP, Lanzhou, People's Republic of China
 
  The RFQ for one of front ends of C-ADS is designed. The frequency of the RFQ is 162.5 MHz and the energy is 2.1 MeV. The beam intensity is 15 mA and it works at CW mode. Because of low frequency, the four-wing structure is big size. It makes fabrication will take more risks. Therefore, four fabrication testing were planned and done to minimize the technic risks. The description about fabrication and testing results are presented in the paper.  
 
MOPB095 Design of MEBT for the Project X Injector Experiment at Fermilab kicker, SRF, quadrupole, diagnostics 398
 
  • A.V. Shemyakin, C.M. Baffes, A.Z. Chen, Y.I. Eidelman, B.M. Hanna, V.A. Lebedev, S. Nagaitsev, J.-F. Ostiguy, R.J. Pasquinelli, D.W. Peterson, L.R. Prost, G.W. Saewert, V.E. Scarpine, B.G. Shteynas, N. Solyak, D. Sun, M. Wendt, V.P. Yakovlev
    Fermilab, Batavia, USA
  • T. Tang
    SLAC, Menlo Park, California, USA
 
  Funding: Fermilab is operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the U.S. DOE
The Project X Injector Experiment (PXIE), a test bed for the Project X front end, will be completed at Fermilab at FY12-16. One of the challenging goals of PXIE is demonstration of the capability to form a 1 mA H beam with an arbitrary selected bunch pattern from the initially 5 mA 162.5 MHz CW train. The bunch selection will be made in the Medium Energy Beam Transport (MEBT) at 2.1 MeV by diverting undesired bunches to an absorber. This paper will present the MEBT scheme and describe development of its elements, including the kickers and absorber.
 
 
TUPLB04 Results of Testing of Multi-beam Klystrons for the European XFEL klystron, cathode, high-voltage, status 448
 
  • V. Vogel, L. Butkowski, A. Cherepenko, S. Choroba, I. Harders, J. Hartung
    DESY, Hamburg, Germany
 
  For the European XFEL multi-beam klystrons, which can produce RF power of 10 MW at an RF frequency of 1.3 GHz, at 1.5 ms pulse length and 10 Hz repetition rate, were chosen as RF power sources. Twenty-seven of horizontal multi-beam klystrons (MBK) together with connection modules (CM) will be installed in the XFEL underground tunnel. The CM will be installed on the MBK and connects the MBK to the pulse transformer with only one HV cable, because the CM has a filament transformer inside as well as all diagnostics for HV and cathode current measurements. MBK prototypes together with CM prototypes have been tested for long time at a test stand at DESY, about 3000 hours of operation for each of horizontal MBK with full RF output power, full pulse length and repetition rate of 10 Hz. Testing of first MBKs from series production has been started. In this paper we will give an overview of the test procedure, summarize the current test results and we will give a comparison of the most important parameters.  
 
TUPB004 Results of Testing of Multi-beam Klystrons for the European XFEL klystron, cathode, high-voltage, status 479
 
  • V. Vogel, L. Butkowski, A. Cherepenko, S. Choroba, I. Harders, J. Hartung
    DESY, Hamburg, Germany
 
  For the European XFEL multi-beam klystrons, which can produce RF power of 10 MW at an RF frequency of 1.3 GHz, at 1.5ms pulse length and 10 Hz repetition rate, were chosen as RF power sources. Twenty-seven of horizontal multi-beam klystrons (MBK) together with connection modules (CM) will be installed in the XFEL underground tunnel. The CM will be installed on the MBK and connects the MBK to the pulse transformer with only one HV cable, because the CM has a filament transformer inside as well as all diagnostics for HV and cathode current measurements. MBK prototypes together with CM prototypes have been tested for long time at a test stand at DESY, about 3000 hours of operation for each of horizontal MBK with full RF output power, full pulse length and repetition rate of 10 Hz. Testing of first MBKs from series production has been started. In this paper we will give an overview of the test procedure, summarize the current test results and we will give a comparison of the most important parameters.  
 
TUPB042 Progress on RFQIII Fabrication in J-PARC Linac rfq, linac, cavity, alignment 570
 
  • T. Morishita
    JAEA/LINAC, Ibaraki-ken, Japan
  • K. Hasegawa, Y. Kondo
    JAEA, Ibaraki-ken, Japan
  • H. Kawamata, F. Naito, T. Sugimura
    KEK, Ibaraki, Japan
 
  The J-PARC accelerator comprises an injector linac, a 3 GeV Rapid-Cycling Synchrotron and a 50 GeV Main Ring. The J-PARC linac has been operating for users with the beam energy of 181 MeV. The energy (to 400 MeV) and current (to 50 mA) upgrade of the linac is scheduled for 1MW operation at RCS. For the current upgrade, the fabrication of a new RFQ, which is designed for 50 mA acceleration, has been started. The engineering design and the fabrication technologies were carefully chosen to reduce the discharge risk during the operation. For good vacuum pumping, vanes and ports are brazed for the direct pumping through slits at the tuners. Also, we tried a chemical polishing to improve the smoothness of the vane surface. In this paper, we present the fabrication progress of a new RFQ in J-PARC linac.  
 
TUPB053 Main Coupler Design for Project X cavity, radiation, linac, cryomodule 594
 
  • S. Kazakov, S. Cheban, T.N. Khabiboulline, M. Kramp, Y. Orlov, V. Poloubotko, O. Pronitchev, V.P. Yakovlev
    Fermilab, Batavia, USA
  • M.S. Champion
    ORNL, Oak Ridge, Tennessee, USA
 
  A multi-megawatt proton/H source, Project X, is under development at Fermi National Accelerator Laboratory. Main element of it is a 3 GeV superconducting proton linac which includes 5 families of superconducting cavities of three frequencies: 162.5, 325 and 650 MHz. Scope of this paper is the development of power couplers for 325 and 650 MHz at FNAL. Upgraded version of the accelerator will require two types of couplers, which reliably can operate at CW power level ~25 kW at 325 MHz and ~100 kW at 650 MHz respectively. In this paper we are describing the current design of these devices.  
 
TUPB068 Cryomodule Designs for Superconducting Half-Wave Resonators cryomodule, alignment, cavity, solenoid 627
 
  • Z.A. Conway, G.L. Cherry, R.L. Fischer, S.M. Gerbick, M. Kedzie, M.P. Kelly, S.H. Kim, J.W. Morgan, P.N. Ostroumov, K.W. Shepard
    ANL, Argonne, USA
 
  Funding: This work was supported by the U.S. DOE, Office of Nuclear Physics, contract number DE-AC02-06CH11357, WFO 85Y47 supported by SNRC, and WFO 82308 supported by Fermi National Accelerator Laboratory.
In this paper we present advanced techniques for the construction of half-wave resonator cryomodules. Recent advances in superconducting low-beta cavity design and processing have yielded dramatically improved cavity performance which reduce accelerator cost and improve operational reliability. This improvement has led to the proposal and construction of half-wave resonators by ANL for the acceleration of 0.1 < \beta < 0.5 ions, e.g., the SARAF Phase-II project at SNRC (SOREQ, Israel) and Project-X at Fermilab. These cryomodules build and improve upon designs and techniques recently implemented in upgrades to ATLAS at ANL. Design issues include the ease of assembly/maintenance, resonator cleanliness, operating at 2 or 4 Kelvin, and ancillary system interfacing.
 
 
TUPB073 Design and Simulation of a Test Model for a Tri-Spoke Cavity at RIKEN cavity, simulation, superconducting-cavity, electron 642
 
  • L. Lu
    RIKEN, Saitama, Japan
  • O. Kamigaito, N. Sakamoto, K. Suda, K. Yamada
    RIKEN Nishina Center, Wako, Japan
 
  A design for a tri-spoke-type superconducting cavity for uranium beams with β = 0.303 and a 219 MHz operational frequency is presented. And a test model designed and assembled by two end-wall flanges and one triparted part of the designed tri-spoke cavity, was expected to be built using the same fabrication technology that is supposed for Nb cavity manufacture. The designs and simulations of the tri-spoke cavity and the test model will be reported in this paper.  
 
TUPB093 Compact 4 kW Variable RF Power Coupler for FRIB Quarter-wave Cavities cavity, cryomodule, simulation, linac 678
 
  • M.P. Kelly, Z.A. Conway, M. Kedzie, S.V. Kutsaev
    ANL, Argonne, USA
  • J.L. Crisp, L.L. Harle
    FRIB, East Lansing, Michigan, USA
 
  A new compact 4 kW power coupler has been designed and prototyped at Argonne National Laboratory in collaboration with Michigan State University. The coupler is intended for use on the β=0.085 80.5 MHz superconducting quarter-wave cavities for the FRIB driver linac and also for the planned ReA6 quarter-wave cavity cryomodule. The design has a cold RF window and a 3 cm variable bellows section. The 16 cm overall length of the RF window and bellows facilitates a simple and compact installation onto the cavity inside the clean room. A prototype have been cold tested with high power under realistic conditions at Argonne and results are presented.  
 
TUPB094 High Power Tests of TRASCO RFQ Couplers cavity, rfq, simulation, klystron 681
 
  • E. Fagotti, L. Antoniazzi, F. Grespan, A. Palmieri, F. Scarpa
    INFN/LNL, Legnaro (PD), Italy
  • O. Brunasso Cattarello, R. Panero
    INFN-Torino, Torino, Italy
  • M. Desmons
    CEA/DSM/IRFU, France
 
  The 352.2 MHz 7.13 m long TRASCO RFQ requires an overall amount of 900 kW CW RF power in order to deliver the 40 mA proton beam from the initial energy of 80 keV to the final energy of 5 MeV. For such a purpose a system of eight compact (ϕext=38 mm, ϕint=19.4 mm) loop-based couplers was designed. In a first phase, only the first two (out of six) modules of the RFQ were tested at full power. Therefore only two (out of eight) couplers were used. In order to completely characterize these couplers, a dedicated test bench was prepared, consisting of a bridge waveguide and diagnostics (reflected power, vacuum, arc detectors etc.), onto which a couple of couplers was connected for transmission measurements. Each coupler was tested with a forward power of up to 140 kW. The description of the experimental setup and procedure, as well as the main results of the conditioning procedure will be reported in this paper.  
 
TUPB099 Input Coupler of the J-PARC DTL coupling, DTL, cavity, linac 690
 
  • F. Naito, K. Nanmo, H. Tanaka
    KEK, Ibaraki, Japan
  • K. Hirano, T. Ito
    JAEA/J-PARC, Tokai-mura, Japan
 
  Each tank of J-PARC DTL has two input couplers. The coupler has a movable coupling loop with an capacitive element which increase the coupling with the tank. The loop position is the outside of the tank, where is the atmosphere. The tank vacuum is kept by the ceramic window on the wall for the coupler port. The ceramic is made of Aluminum oxide of 99.7 % purity. RF properties and the mechanical structure of the coupler were designed adequately in order to achieve the desired performance. We will report the design of the coupler in detail and the experiences for the practical operation of the DTL.  
 
TUPB102 Design and Performances of Phase Monitor in J-PARC Linac linac, acceleration, pick-up, impedance 699
 
  • A. Miura
    JAEA/J-PARC, Tokai-mura, Japan
  • Z. Igarashi, T. Miyao
    KEK, Ibaraki, Japan
 
  J-PARC linac employs a fast current transformer (FCT) as a beam phase monitor to calculate the beam energy by time-of-flight method. We have installed and used 61 FCTs in the current beam line. Because the phase measurements at additional 41 points in the future ACS sections are required for the energy upgrade project with adding 21 ACS (Annular Coupled Structure) cavities, we stared the design and fabrication of FCTs as the phase measurement devices. In addition, J-PARC linac employs the 4-stripline beam position monitors (BPMs) for the beam position measurement. It has been considered that the signals from striplines of BPM would be useful for a phase measurement. A phase measurement using a BPM has been successfully conducted. In order to evaluate the performances of the FCT, the signal sensitivity and cut-off frequency of newly fabricated FCT are measured. Also, these data of the BPM are also measured to be compared with the data of FCT. Based on the results of the comparing both measurements, the superiority of both monitors for beam phase measurement is discussed.  
 
TUPB103 CSNS DTL Prototyping and RF Tuning DTL, cavity, linac, quadrupole 702
 
  • H.C. Liu, Q. Chen, S. Fu, K.Y. Gong, A.H. Li, J. Peng, Y.C. Xiao, X. Yin
    IHEP, Beijing, People's Republic of China
 
  The 324 MHz Alvarez-type Drift Tube Linac (DTL) for the China spallation neutron source will be used to accelerate the H ion beam of up to 15 mA peak current from 3 to 80 MeV. It consists of four independent tanks, of which the average length is about 8.6 m. Each tank is divided into three short unit tanks about 2.8 m in length for easy manufacture. A full-scale prototype of the first unit tank with 28 drift tubes containing electromagnetic quadrupoles has been constructed to validate the design and to demonstrate the technology. The overall features of the prototype in both key technology and RF tuning are presented. In particular, the influence of the post couplers was studied in the ramped field DTL.  
 
TH2A03 Design and Construction of the Linac4 Accelerating Structures linac, DTL, rfq, cavity 778
 
  • F. Gerigk, Y. Cuvet, A. Dallocchio, G. Favre, J.-M. Geisser, L. Gentini, J.-M. Giguet, S.J. Mathot, M. Polini, S. Ramberger, B. Riffaud, C. Rossi, P. Ugena Tirado, M. Vretenar, R. Wegner
    CERN, Geneva, Switzerland
  • E. Kendjebulatov, Ya.G. Kruchkov, A.G. Tribendis
    BINP SB RAS, Novosibirsk, Russia
  • M.Y. Naumenko
    RFNC-VNIITF, Snezhinsk, Chelyabinsk region, Russia
 
  The Linac4 project at CERN is at an advanced state of construction. Prototypes of the different types of accelerating structures (RFQ, DTL, CCDTL and pi-mode structures) have been built and are presently tested. This paper gives the status of the cavity production and reviews the RF and mechanical design of the various structure types. Furthermore the production and the first test results shall be presented.  
slides icon Slides TH2A03 [2.675 MB]  
 
THPLB08 High-Power RF Conditioning of the TRASCO RFQ rfq, cavity, controls, pick-up 828
 
  • E. Fagotti, L. Antoniazzi, F. Grespan, A. Palmieri
    INFN/LNL, Legnaro (PD), Italy
  • M. Desmons
    CEA/DSM/IRFU, France
 
  The TRASCO RFQ is designed to accelerate a 40 mA proton beam up to 5 MeV. It is a CW machine which has to show stable operation and provide the requested availability. It is composed of three electromagnetic segment coupled via two coupling cells. Each segment is divided into two 1.2 m long OFE copper modules. The RFQ is fed through eight loop-based power couplers to deliver RF to the cavity from a 352.2 MHZ, 1.3 MW klystron. After couplers conditioning, the first electromagnetic segment was successfully tested at full power. RFQ cavity reached the nominal 68 kV inter-vane voltage (1.8 Kilp.) in CW operation. Moreover, during conditioning in pulsed operation, it was possible to reach 83 kV inter-vane voltage (2.2 Kilp.) with a 1% duty cycle. The description of the experimental setup and procedure, as well as the main results of the conditioning procedure will be reported in this paper.  
slides icon Slides THPLB08 [1.384 MB]  
 
THPLB09 Status of E-XFEL String and Cryomodule Assembly at CEA-Saclay cryomodule, cavity, controls, synchrotron 831
 
  • C. Madec
    CEA, Gif-sur-Yvette, France
  • S. Berry, J.-P. Charrier, A. Daël, M. Fontaine, Y. Gasser, O. Napoly, Y. Sauce, C.S. Simon, T.V. Vacher, B. Visentin
    CEA/DSM/IRFU, France
  • A. Brasseur, P. Charon, C. Cloué, S. Langlois, G. Monnereau, J.L. Perrin, D. Roudier, N. Sacépé
    CEA/IRFU, Gif-sur-Yvette, France
 
  As In-Kind contributor to E-XFEL project, CEA is committed to the integration on the Saclay site of the 100 cryomodules of the superconducting linac as well as to the procurement of the magnetic shieldings, superinsulation blankets and 31 cold beam position monitors of the re-entrant type. The assembly infrastructure has been renovated from the previous Saturne Synchrotron Laboratory facility: it includes a 200 m2 clean room complex with 120 m2 under ISO4, 1325 m2 of assembly platforms and 400 m2 of storage area. In parallel, CEA has conducted industrial studies and three cryomodule assembly prototyping both aiming at preparing the industrial file, the quality management system and the commissioning of the assembly plant, tooling and control equipments. In 2012, the contract of the integration will be placed to a subcontractor. The paper will summarize the outputs of the preparation and prototyping phases and the up-coming industrial phase.  
 
THPB020 Annular-ring Coupled Structure for the Energy Upgrade of the J-PARC Linac linac, cavity, coupling, target 888
 
  • H. Ao, H. Asano, N. Ouchi, J. Tamura
    JAEA/J-PARC, Tokai-mura, Japan
  • F. Naito, K. Takata
    KEK, Ibaraki, Japan
 
  The linac of Japan Proton Accelerator Research Complex (J-PARC), which is an injector to the synchrotron, comprises a 3-MeV RFQ, 50-MeV DTLs and the 181-MeV Separated-type DTLs. In order to increase the beam power of the synchrotron, the task of the 400-MeV energy upgrade of the linac started from March 2009. The tanks of the Annular-ring Coupled Structure (ACS) linac, RF sources, beam monitors and utilities are in production. Although some peripheral components of the ACS linac are prepared previously, the all ACS tanks will be installed and conditioned for 4 months from July 2013. Beam commissioning of the 400-MeV linac is scheduled to begin in October and expected to finish at the end of November 2013. In this paper, we present the current status of the energy upgrade and some R&D results for new equipment for ACS linac.  
 
THPB021 Recovery Efforts from the Tohoku Earthquake and Energy Upgrade Preparation of the Beam Transport from the J-PARC Linac to the 3-GeV Synchrotron linac, radiation, beam-transport, synchrotron 891
 
  • J. Tamura, H. Ao, H. Asano, T. Morishita, N. Ouchi
    JAEA/J-PARC, Tokai-mura, Japan
  • Y. Sawabe
    MELCO SC, Tsukuba, Japan
 
  In 2013, the beam energy of the Japan Proton Accelerator Research Complex (J-PARC) linac is going to be increased from 181-MeV to 400-MeV by adding the annular-ring coupled structure (ACS) at the downstream of the 191-MeV drift tube linac. To install and operate all the ACS cavities in only five months of the energy upgrade shutdown in 2013, we decided to replace and upgrade all the related component of the beam line (cables, magnet power supplies and vacuum control systems) for the 400-MeV operation, in the period of the recovery from the Tohoku Earthquake which caused not negligible damage to the J-PARC accelerator facilities. The present beam line is operated by using some part of the 400-MeV componets. In this paper, the recovery of the beam transport, the present status and the future tasks of the beam energy upgrade will be presented.  
 
THPB025 325 MHz CW Room Temperature High Power Bunching Cavity for the China ADS MEBT1 cavity, bunching, impedance, resonance 903
 
  • S. Pei, X. Li, H.F. Ouyang, J.R. Zhang
    IHEP, Beijing, People's Republic of China
 
  Two room temperature high power bunching cavities are required to be located in the ADS MEBT1 section. Double re–entrant nose cone geometry has been adopted as the type of the bunching cavity for its simplicity, higher shunt impedance and lower risk of multipacting. SUPERFISH is used to optimize the internal dimensions of the bunching cavity, then the RF–thermal–structural–RF coupled analysis were carried out in ANSYS to obtain the preliminary mechanical design, the layout of the cooling channels is optimized to suppress the frequency shift as much as possible. The cavity was specially designed to have the capability to withstand the 1 atm air pressure effect. In addition, the main dimensions of the coupler and tuner are also estimated.
*peisl@ihep.ac.cn
 
 
THPB040 High-Power RF Conditioning of the TRASCO RFQ rfq, cavity, controls, pick-up 945
 
  • E. Fagotti, L. Antoniazzi, F. Grespan, A. Palmieri
    INFN/LNL, Legnaro (PD), Italy
  • M. Desmons
    CEA/DSM/IRFU, France
 
  The TRASCO RFQ is designed to accelerate a 40 mA proton beam up to 5 MeV. It is a CW machine which has to show stable operation and provide the requested availability. It is composed of three electromagnetic segment coupled via two coupling cells. Each segment is divided into two 1.2 m long OFE copper modules. The RFQ is fed through eight loop-based power couplers to deliver RF to the cavity from a 352.2 MHZ, 1.3 MW klystron. After couplers conditioning, the first electromagnetic segment was successfully tested at full power. RFQ cavity reached the nominal 68 kV inter-vane voltage (1.8 Kilp.) in CW operation. Moreover, during conditioning in pulsed operation, it was possible to reach 83 kV inter-vane voltage (2.2 Kilp.) with a 1% duty cycle. The description of the experimental setup and procedure, as well as the main results of the conditioning procedure will be reported in this paper.  
 
THPB052 Recent Progress with the J-PARC RFQs rfq, linac, emittance, simulation 972
 
  • Y. Kondo, K. Hasegawa, T. Morishita
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • H. Kawamata, F. Naito, T. Sugimura
    KEK, Ibaraki, Japan
 
  In this paper, we will report recent topics about J-PARC RFQs. First, the operating RFQ (RFQ I) have been recovered from the long shutdown due to the earthquake. This RFQ have been suffered from breakdown problem since 2008, therefore we have been developing a back-up RFQ (RFQ II). In April 2012, the high power test was successfully performed. Finally, we are fabricating a new RFQ for the beam-current upgrade of the J-PARC linac (RFQ III). The status of these RFQs are described.  
 
THPB074 RF Photoinjector and Radiating Structure for High-power THz Radiation Source radiation, coupling, electron, impedance 1005
 
  • S.M. Polozov, T.V. Bondarenko
    MEPhI, Moscow, Russia
  • Y.A. Bashmakov
    LPI, Moscow, Russia
 
  Sources of high-power electromagnetic radiation in THz band are becoming promising as a new method of a low activation introscopy. Research and development of accelerating RF photoinjector and radiating system for THz radiation source are reported. The photoinjector is based on disk loaded waveguide (DLW). Two different designs of accelerating structures were modeled: widespread 1.6 cell of DLW structure and travelling wave resonator structure. The resonant models of these structures and the structures with power ports were designed. Electrodynamics characteristics and electric field distribution for all models were acquired. Results of picoseconds photoelectron beam dynamics in modeled structures are reported. Design of decelerating structures exciting Cherenkov radiation are based on corrugated metal channel and metal channel coated with dielectric. Analysis of radiation intensity and frequency band are presented.  
 
THPB083 Status of E-XFEL String and Cryomodule Assembly at CEA-Saclay cryomodule, cavity, controls, synchrotron 1017
 
  • C. Madec
    CEA, Gif-sur-Yvette, France
  • S. Berry, J.-P. Charrier, A. Daël, M. Fontaine, Y. Gasser, O. Napoly, Y. Sauce, C.S. Simon, T.V. Vacher, B. Visentin
    CEA/DSM/IRFU, France
  • A. Brasseur, P. Charon, C. Cloué, S. Langlois, G. Monnereau, J.L. Perrin, D. Roudier, N. Sacépé
    CEA/IRFU, Gif-sur-Yvette, France
 
  As In-Kind contributor to E-XFEL project, CEA is committed to the integration on the Saclay site of the 100 cryomodules of the superconducting linac as well as to the procurement of the magnetic shieldings, superinsulation blankets and 31 cold beam position monitors of the re-entrant type. The assembly infrastructure has been renovated from the previous Saturne Synchrotron Laboratory facility: it includes a 200 m2 clean room complex with 120 m2 under ISO4, 1325 m2 of assembly platforms and 400 m2 of storage area. In parallel, CEA has conducted industrial studies and three cryomodule assembly prototyping both aiming at preparing the industrial file, the quality management system and the commissioning of the assembly plant, tooling and control equipments. In 2012, the contract of the integration will be placed to a subcontractor. The paper will summarize the outputs of the preparation and prototyping phases and the up-coming industrial phase.  
slides icon Slides THPB083 [1.868 MB]  
 
THPB095 Designing of a Phase-mask-type Laser Driven Dielectric Accelerator for Radiobiology laser, electron, acceleration, simulation 1041
 
  • K. Koyama
    UTNL, Ibaraki, Japan
  • A. Aimidura, M. Uesaka
    The University of Tokyo, Nuclear Professional School, Ibaraki-ken, Japan
  • Y. Matsumura
    University of Tokyo, Tokyo, Japan
  • T. Natsui, M. Yoshida
    KEK, Ibaraki, Japan
 
  Funding: This work is supported by KAKENHI, Grant-in-Aid for Scientific Research (C) 24510120
In order to estimate the health risk of a low radiation dose, basic processes of the radiobiology should be clarified by shooting a DNA using a spatially and temporary defined particle beam or X-ray. A suitable beam size is as small as a resolving power of an optical microscope of a few hundred nanometers. Photonic crystal accelerators (PCA) are capable of delivering nm-beams of sub-fs pulses because the characteristic length and frequency of PCAs are on the order of the laser light. Since the phase-mask type accelerator has a simpler structure than other types of PCAs, we are designing a phase-mask type laser driven dielectric accelerator. By adopting an unbalanced length of pillar and ditch (grating) of 4:1, a standing wave like acceleration field is produced in a acceleration channel. A pillar height and initial speed of injected electron are determined by analytically. The maximum acceleration gradient of 2 GeV/m is estimated. The required laser power is roughly estimated to be 6.5 GW. The simulation using CST-code also shows similar values to accelerate electrons by the phase-mask type accelerator.
 
 
FR2A01 Recovery of the J-PARC Linac from the Earthquake linac, DTL, ion, rfq 1069
 
  • K. Hasegawa
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
 
  Following the amazingly quick recovery from the disastrous earthquake in March 2011, and in the interests of promoting robust designs of linacs, it would be interesting to learn what the J-PARC team reckons are the key features of accelerator design and construction that lead to strong and reliable hardware.  
slides icon Slides FR2A01 [3.928 MB]