Keyword: cryomodule
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MOPEA048 Operation Status of RF System for the PLS-II Storage Ring SRF, klystron, status, LLRF 187
 
  • M.-H. Chun, J.Y. Huang, Y.D. Joo, H.-G. Kim, S.H. Nam, C.D. Park, H.J. Park, I.S. Park, Y.U. Sohn, I.H. Yu
    PAL, Pohang, Kyungbuk, Republic of Korea
  
  Funding: Supported by the Korea Ministry of Science and Technology
The RF system of the Pohang Light Source-II (PLS-II) storage ring is operating at the 3.0GeV/200mA with two superconducting RF (SRF) cavities. Each RF station is composed with a 300kW klystron with power supply unit, transmission components, a digital LLRF and a SRF cavity. And a cryogenic system of 700W capacities is supplied the LHe and LN2 to three cryomodules of SRF cavities. The second SRF cavity is installed during at the beginning in 2013 and the third one will be installed during summer shutdown in 2014 for stable 400mA operation with all 20 insertion devices. Also the third high power RF station with a 300kW klystron, power supply unit and WR1800 waveguide components will be prepared in 2013. The third LLRF system is already installed, but improved stabilities of amplitude, phase and tuner control. This paper describes the present operation status and improve plan of the RF system for the PLS-II storage ring. 		 
 
MOPME019 Alignment Detection Study using Beam Induced HOM at STF HOM, cavity, dipole, alignment 509
 
  • A. Kuramoto
    Sokendai, Ibaraki, Japan
  • H. Hayano
    KEK, Ibaraki, Japan
  
  STF accelerator using L-band photocathode RF Gun and two superconducting cavities is under operation for R&D of ILC. Electron beam extracted from the RF Gun is accelerated to 40 MeV by two superconducting cavities. Cavity alignment requirements for ILC are less than 300um offset and 300urad tilt with respect to cryomodule. It is necessary to measure their offset and tilt inside of cryomodule. Cavity offset has been already measured by using beam induced HOM at FLASH in DESY. Cavity deformation during assembly and by cooling contraction has not been examined yet. We measured HOM signals to detect their tilt and bending. TE111-6 which has high impedance is used to estimate cavity offset. To find cavity tilt and bending, we selected pi over nine mode in the first dipole passband (TE111-1) and beam pipe modes. From information of TE111-1 which has maximum radial electric field in the middle cell, we can get electrical center of middle cell. At beam pipes, electrical center can be found by using beam pipe modes. Combinations of these electrical centers tell us cavity tilt and bending. We will present results of these TE111-1 and beam pipe mode together with beam trajectory information.  
 
MOPME045 Design and Test Status of Beam Position Monitors for ADS Injector II Proton LINAC proton, linac, vacuum, alignment 574
 
  • Y. Zhang, H. Jia, X.C. Kang, M. Li, J.X. Wu, G. Zhu
    IMP, Lanzhou, People's Republic of China
  
  Beam Position Monitors (BPM) based on capacitive pick-ups are designed for Accelerator-Driven System (ADS) Injector II proton LINAC. This LINAC is aiming to produce a maximum design current of 15 mA at the 10 MeV energy with an operating frequency of 162.5 MHz. Non-interceptive BPM will be installed to measure the transverse beam position and beam phase in the vacuum chamber. Depending on the location, the response of the BPMs must be optimized for a beam with an energy range from 2.1 up to 10 MeV and an average current between 0.01 and 15 mA. Apart from the broadening of the electromagnetic field due to the low-beta beam, specific issues are affecting some of the BPMs: tiny space in the transport line between the RFQ and the cryomodule and the cryogenic temperature inside the cryomodule. For this reason two types of BPMs are being designed for each location (MEBT and cryomoudle). In this contribution, the present status of the design and measured results for each BPM will be presented in room and cold temperature, focusing on the electromagnetic response for low-beta beams.  
 
MOPME072 Performance Tests of a Short Faraday Cup Designed for HIE-ISOLDE electron, ion, diagnostics, cryogenics 646
 
  • E.D. Cantero, W. Andreazza, E. Bravin, M.A. Fraser, D. Lanaia, A.G. Sosa, D. Voulot
    CERN, Geneva, Switzerland
  
  Funding: E.D.C, D.L. and A.S. acknowledge CATHI Marie Curie ITN: EU-FP7-PEOPLE-2010-ITN Project number 264330. M.A.F acknowledges co-funding by the European Commission (Grant agreement PCOFUND-GA-2010-267194)
The On-Line Isotope Mass Separator (ISOLDE) facility at CERN is being upgraded in order to deliver higher energy and intensity radioactive beams. The final setup will consist in replacing the energy variable part of the normal conducting REX post-accelerator with superconducting cavities. In order to preserve the beam emittance, the drift space between the cryomodules housing these cavities has been kept to a minimum. As a consequence, the longitudinal space available for beam diagnostics is severely limited in the inter-cryomodule regions. A Faraday cup (FC) will be installed to measure beam currents, and due to the tight spatial constraints, its length is much smaller than usual. This poses a great challenge when trying to avoid the escape of ion-induced secondary electrons, which would falsify the current measurement. Two prototypes of such a short FC have therefore been tested at REX-ISOLDE using several beam intensities and energies, with the aim of determining its accuracy. In this paper the experimental results obtained for the two prototype cups are presented together with numerical calculations of the electrostatic fields that are produced inside the cup. 		 
 
MOPWA063 Proposed Coherent Diffraction Radiation Measurements of Bunch Length at ASTA radiation, electron, gun, laser 822
 
  • A.H. Lumpkin, J. Ruan, R.M. Thurman-Keup
    Fermilab, Batavia, USA
  
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The feasibility of using the autocorrelation of coherent diffraction radiation (CDR) as a non-intercepting diagnostics technique for bunch length and indirectly rf phase measurements is evaluated and proposed for the Advanced Superconducting Test Accelerator (ASTA) facility under construction at Fermilab. Previous experiments on an rf thermionic cathode gun beam at 50 MeV provide a proof-of-principle reference for the ASTA injector. The ASTA injector is based on an L-band rf photocathode (PC) gun with UV pulse drive laser, two L-band superconducting accelerator structures, a chicane bunch compressor, and an electron spectrometer. The injector energy of 40-50 MeV is expected. The 3-MHz micropulse repetition rate with micropulse charges up to to 3.2 nC and 1-ps bunch lengths should generate sufficient CDR signal for standard pyroelectric detectors to be used. The CDR signals will also be evaluated as a bunch compression signal for beam-based feedback for rf phase. The technique would also be applicable at high energy in straight transport lines after the cryomodules. 		 
 
TUOAB102 Project X Injector Experiment: Goals, Plan and Status kicker, rfq, ion, solenoid 1093
 
  • A.V. Shemyakin, S.D. Holmes, D.E. Johnson, M. Kaducak, R.D. Kephart, V.A. Lebedev, C.S. Mishra, S. Nagaitsev, N. Solyak, R.P. Stanek, V.P. Yakovlev
    Fermilab, Batavia, USA
  • D. Li
    LBNL, Berkeley, California, USA
  • P.N. Ostroumov
    ANL, Argonne, USA
  
  Funding: This work was supported by the U.S. DOE under Contract No.DE-AC02-07CH11359
A multi-MW proton facility, Project X, has been proposed and is currently under development at Fermilab. We are carrying out a program of research and development aimed at integrated systems testing of critical components comprising the front end of the Project X. This program is being undertaken as a key component of the larger Project X R&D program. The successful completion of this program will validate the concept for the Project X front end, thereby minimizing a primary technical risk element within Project X. Integrated systems testing, known as the Project X Injector Experiment (PXIE), will be accomplished with a new test facility under construction at Fermilab and will be completed over the period FY12- 17. PXIE will include an H− ion source, a CW 2.1-MeV RFQ and two superconductive RF (SRF) cryomodules providing up to 25 MeV energy gain at an average beam current of 1 mA (upgradable to 2 mA). Successful systems testing will also demonstrate the viability of novel front end technologies that are expected find applications beyond Project X. 		 
slides icon Slides TUOAB102 [1.615 MB]  
 
TUPEA003 Components for CW and LP Operation of the XFEL Linac cavity, linac, HOM, cathode 1164
 
  • J.K. Sekutowicz
    DESY, Hamburg, Germany
  
  The European XFEL will use superconducting TESLA cavities operating with 650 μs long bunch trains. With 220 ns bunch spacing and 10 Hz RF-pulse repetition rate, up to 27000 high quality bunches/s will be delivered to insertion devices generating unprecedented high average brilliance photon beams at very short wavelength. While many experiments can take advantage of full bunch trains, others prefer an increased intra-pulse distance of several μ-seconds between bunches, or short bursts with a kHz repetition rate. In this contribution, we discuss progress in the R&D program for a future upgrade of the European XFEL linac, to operation in the continuous wave (cw) and long pulse (lp) mode, which will allow for much more flexibility in the electron and photon beam time structure. Modifications and cw tests of XFEL cryomodules, recent tests result of the SRF injector, test of the second prototype of 120 kW IOT are presented. In addition, computer modeling of the cw-operating TESLA-like cavity with modified HOM couplers is briefly discussed.  
 
TUPWA054 PXIE End-to-end Simulations rfq, simulation, solenoid, emittance 1829
 
  • J.-F. Ostiguy, J.-P. Carneiro, V.A. Lebedev, A. Saini, N. Solyak
    Fermilab, Batavia, USA
  
  Funding: US DOE contract DE-AC02-76CH03000.
Construction of PXIE, (Project-X Injector Experiment) has recently begun. The goal is to validate the design of the injector and low energy acceleration front-end for a future Project-X. PXIE operates in CW mode and consists in an ion source, a magnetically focused LEBT, a 162.5 MHz RFQ, a MEBT equipped with high bandwidth traveling wave kickers, a cryomodule equipped with 162.5 MHz half-wave resonators and a single cryomodule based on 325 MHz spoke resonators. The arrangement is meant to be closely representative of a future Project-X front end, and will include a variety of diagnostics. In this contribution we present detailed end-to-end tracking simulations. In particular, we examine possible impact of the RFQ longitudinal distribution, neutralization effects in the LEBT as well as of various imperfections in the MEBT on losses in the first superconducting cavities. 		 
 
WEOBB102 Design Integration of the FRIB Driver Linac linac, solenoid, SRF, ion 2055
 
  • Y. Zhang, N.K. Bultman, F. Casagrande, C.P. Chu, A. Facco, P.E. Gibson, Z.Q. He, K. Holland, M. Leitner, Z. Liu, F. Marti, D. Morris, S. Peng, E. Pozdeyev, T. Russo, J. Wei, Y. Yamazaki, Z. Zheng
    FRIB, East Lansing, Michigan, USA
  
  Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
FRIB driver linac will deliver all stable heavy ion beams with beam energy more than 200 MeV/u, and beam power on target up to 400 kW. As the first SRF linac for high power heavy ion beams, there are many technical challenges, and integration of all the accelerator components is important. In this paper, major issues on integration of the FRIB drive linac are introduced and the corresponding studies are discussed, which include developments of accelerator online model, minimize uncontrolled beam loss in the SRF linac for high power heavy ion beams, beam diagnostic systems for beam tuning and for machine protection system (MPS), secondary collimators for charge selection of multi charge state ion beams, beam loading and stability of LLRF control, proper degauss process with superconducting (SC) solenoids when combined with SC dipole correctors, vacuum system, cryogenic and distribution system, helium pressure drop and stability of the cryomodules. 		 
slides icon Slides WEOBB102 [3.557 MB]  
 
WEPWA004 Multi-turn ERL Based Light Source: Analysis of Injection and Recovery Schemes linac, optics, injection, acceleration 2129
 
  • Y. Petenev, T. Atkinson, A.V. Bondarenko, A.N. Matveenko
    HZB, Berlin, Germany
  
  The optics simulation group at HZB is designing a multi-turn energy recovery linac -based light source. Using the superconducting Linac technology, the Femto-Science-Factory(FSF) will provide its users with ultra-bright photon beams of angstrom wavelength. The FSF is intended to be a multi-user facility and offer a variety of operation modes. The driver of the facility is a 6GeV multiturn energy recovery linac with a split linac. In this paper we compare different schemes of beam acceleration: a direct injection scheme with acceleration in a 6 GeV linac, a two-stage injection with acceleration in a 6 GeV linac, and a multi-turn (3-turn) scheme with a two-stage injection and two main 1 GeV linacs. The key points were costs and beam break up instability.  
 
WEPWA015 Progress in Construction of the 35 MeV Compact Energy Recovery Linac at KEK linac, gun, shielding, laser 2159
 
  • S. Sakanaka, S. Adachi, M. Akemoto, D.A. Arakawa, S. Asaoka, K. Enami, K. Endo, S. Fukuda, T. Furuya, K. Haga, K. Hara, K. Harada, T. Honda, Y. Honda, H. Honma, T. Honma, K. Hosoyama, K. Hozumi, E. Kako, Y. Kamiya, H. Katagiri, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondou, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura, T. Miyajima, S. Nagahashi, H. Nakai, H. Nakajima, N. Nakamura, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Obina, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sasaki, K. Satoh, M. Satoh, T. Shidara, M. Shimada, K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Takahashi, R. Takai, T. Takenaka, Y. Tanimoto, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida
    KEK, Ibaraki, Japan
  • E. Cenni
    Sokendai, Ibaraki, Japan
  • R. Hajima, S.M. Matsuba, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma
    JAEA, Ibaraki-ken, Japan
  • H. Takaki
    ISSP/SRL, Chiba, Japan
  
  The 35-MeV Compact Energy Recovery Linac (the Compact ERL or cERL) is under construction at the High Energy Accelerator Research Organization (KEK) in Japan. With the Compact ERL, we aim at establishing cutting-edge technologies for the GeV-class ERL-based synchrotron light source. To install the accelerator components of the cERL, we have constructed a shielding room having an area of about 60 m x 20 m. We have then installed a 500-kV DC photocathode gun, a 5-MV superconducting (SC) cryomodule for the injector, a 30-MV SC cryomodule for the main linac, and some of the other components. High-power test on the main SC cryomodule is underway in December, 2012. High-power or high-voltage tests on the injector cryomodule and on the DC gun are planned during January to March, 2013. An injector of the Compact ERL will be commissioned in April, 2013. We report the newest status of its construction.  
 
WEPWA068 Design Concepts for the NGLS Linac cavity, linac, cryogenics, HOM 2271
 
  • A. Ratti, J.M. Byrd, J.N. Corlett, L.R. Doolittle, P. Emma, J. Qiang, M. Venturini, R.P. Wells
    LBNL, Berkeley, California, USA
  • C. Adolphsen, C.D. Nantista
    SLAC, Menlo Park, California, USA
  • D. Arenius, S.V. Benson, D. Douglas, A. Hutton, G. Neil, W. Oren, G.P. Williams
    JLAB, Newport News, Virginia, USA
  • C.M. Ginsburg, R.D. Kephart, T.J. Peterson, A.I. Sukhanov
    Fermilab, Batavia, USA
  
  The Next Generation Light Source (NGLS) is a design concept for a multibeamline soft x-ray FEL array powered by a ~2.4 GeV CW superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. This paper describes the concepts under development for a linac operating at 1.3 GHZ and based on minimal modifications to the design of ILC cryomodules in order to leverage the extensive R&D that resulted in the ILC design. Due to the different nature of the two applications, particular attention is given here to high loaded Q operation andμphonics control, as well as high reliability and expected up time.  
 
WEPWO008 SRF Conical Half-wave Resonator Tuning Developments cavity, simulation, target, resonance 2325
 
  • E.N. Zaplatin
    FZJ, Jülich, Germany
  • A. Kanareykin
    Euclid TechLabs, LLC, Solon, Ohio, USA
  
  Funding: This Work is supported by the DOE SBIR Program, contract # DE-SC0006302.
A conical Half-Wave Resonator is considered as an option for a first accelerating cavity for β=v/c=0.11 with the resonance frequency 162.5 MHz for a high-intensity proton accelerator complex proposed at Fermi National Accelerator Laboratory (Project X). We present results of different options of the cavity mechanical tuning. The "standard" tuning method of beam port deformations is an effective tuning method still requiring a relatively high tuning pressure. The side tuning is considered as a novel option for the resonance frequency adjustment featuring lower tuning force and an option of the structure design for the resonator frequency shift self compensation. 		 
 
WEPWO013 High Power Tests of Injector Cryomodule for Compact-ERL cavity, HOM, radiation, accelerating-gradient 2340
 
  • E. Kako, D.A. Arakawa, K. Hara, T. Honma, H. Katagiri, Y. Kojima, Y. Kondo, S. Michizono, T. Miura, H. Nakai, H. Nakajima, K. Nakanishi, S. Noguchi, T. Shishido, T. Takenaka, K. Watanabe, Y. Yamamoto
    KEK, Ibaraki, Japan
  • H. Hara, H. Hitomi, K. Sennyu
    MHI, Kobe, Japan
  
  In the cERL injector cryomodule, electron beams of 10 mA are accelerated from the beam energy of 500 keV to 5 MeV. A three 2-cell cavity system was chosen for the cERL injector. Each cavity is driven by two input couplers to reduce a required RF power handling capacity and also to compensate a coupler kick. In the cERL injector cryomodule, critical hardware components are not superconducting cavities but RF input couplers operating in CW mode. Six input couplers for the installation in the cryomodule were fabricated, and three pairs of input couplers were carefully conditioned. Costruction status, cool-down tests and high power RF test results on injector cryomodule for compact-ERL at KEK will be discussed in this paper.  
 
WEPWO016 Construction of Main Linac Cryomodule for Compact ERL Project HOM, cavity, linac, radiation 2349
 
  • K. Umemori, K. Enami, T. Furuya, H. Sakai, M. Satoh, K. Shinoe
    KEK, Ibaraki, Japan
  • E. Cenni
    Sokendai, Ibaraki, Japan
  • M. Sawamura
    JAEA, Ibaraki-ken, Japan
  
  Compact ERL (cERL), which is a test facility of ERL, is under construction at KEK, in Japan. At the first stage of cERL project, electron beam will be accelerated by 30 MV at main linac region. We have developed a main linac cryomodule, which contains two L-band 9-cell superconducting cavities. Cavity assembly work was carefully done at a class-10 clean room and HOM absorbers and cold windows of input couplers were successfully mounted on the cavities. Next, the frequency tuners, thermal anchors, magnetic shields and temperature sensors and so on were assembled to the cryomodule. Then, using a clean-booth, warm windows of the input couplers are connected to the cold windows and gate valves were also attached to the both ends of the cryomodule. Finally, the cryomodule was installed into the beamline of cERL and connected to a 2K cryogenic system. Target of alignment precision of the cavities, after cooling down to 2K, are set to be within 1 mm against the beamline. The first cool-down test, followed by low power and high power measurements, is scheduled within the year 2012.  
 
WEPWO018 Status of the IHEP 1.3 GHz Superconducting RF Program for the ILC cavity, SRF, vacuum, HOM 2355
 
  • J. Gao, Y.L. Chi, J.P. Dai, R. Ge, T.M. Huang, S. Jin, C. H. Li, S.P. Li, Z.Q. Li, H.Y. Lin, Y. Liu, Z.C. Liu, Q. Ma, Z.H. Mi, W.M. Pan, Y. Sun, J.Y. Zhai, T.X. Zhao, H.J. Zheng
    IHEP, Beijing, People's Republic of China
  
  The 1.3 GHz superconducting radio-frequency (SRF) technology is one of the key technologies for the ILC. IHEP is building an SRF Accelerating Unit, named the IHEP ILC Test Cryomodule (IHEP ILC-TC1), for the ILC SRF system integration study, high power horizontal test and possible beam test in the future. In this paper, we report the components test results and the assembly preparation of this cryomodule. Processing and vertical test of the large grain low-loss shape 9-cell cavity is done. Performance of the in-house made high power input coupler and tuner at room temperature reaches the ILC specification.  
 
WEPWO022 IHEP03 Fabrication and Testing Status cavity, niobium, HOM, status 2364
 
  • Z.C. Liu, J. Gao, S. Jin, Y. Liu, J.Y. Zhai, T.X. Zhao, H.J. Zheng
    IHEP, Beijing, People's Republic of China
  • J.X. Wang, H. Yu, H. Yuan
    BIAM, Beijing, People's Republic of China
  
  IHEP is developing RF superconducting technology with different type of superconducting cavities. Tesla-like cavity which is designed by KEK is one of them. We have fabricated all the parts of the cavity using Nb material from Ningxia and cavity welding will be started soon. This paper will show the cavity fabrication procedures and measurement results.  
 
WEPWO053 SRF Development for a MW Proton Source at Fermi National Accelerator Laboratory cavity, linac, SRF, HOM 2423
 
  • T.T. Arkan, C.M. Ginsburg, A. Grassellino, S. Kazakov, T.N. Khabiboulline, T.H. Nicol, Y. Orlov, T.J. Peterson, L. Ristori, A. Romanenko, A.M. Rowe, N. Solyak, A.I. Sukhanov, V.P. Yakovlev
    Fermilab, Batavia, USA
  
  Funding: Work supported by the US Department of Energy
Fermilab is planning a megawatt-level proton beam facility utilizing niobium superconducting RF (SRF) cavities. Project X at Fermilab will eventually provide high-intensity beams for research into the nature of matter at the "intensity frontier". Research and development in several areas will bring the SRF technology to the level needed for this application. Among developments in SRF being pursued with our national and international collaborators are 162.5 MHz half-wave resonators, 325 MHz single-spoke resonators, and two types of elliptical multi-cell 650 MHz cavities. Performance requirements for these cavities and cryomodules in continuous wave (CW) operation are extremely stringent in order to provide high accelerating gradients with acceptable total cryogenic load and overall accelerator capital and operating costs. This paper presents some highlights of the SRF R&D program and proton linac development work at Fermilab. 		 
 
WEPWO055 Fabrication and Testing of SSR1 Resonators for PXIE cavity, linac, vacuum, beam-transport 2429
 
  • L. Ristori, M.H. Awida, P. Berrutti, T.N. Khabiboulline, M. Merio, D. Passarelli, A.M. Rowe, D.A. Sergatskov, A.I. Sukhanov
    Fermilab, Batavia, USA
  
  Fermilab is in the process of constructing a proton linac to accelerate a 1 mA CW beam up to 30 MeV. It will be a test for the front end of Project X and known as the Project X Injector Experiment (PXIE). The major goal of PXIE is the validation of the Project X concept and mitigation of technical risks. It is expected to be constructed in the period of 2012-2016. The PXIE linac consists of a Ion source and LEBT, a 162.5 MHz RFQ, a MEBT, a 162.5 MHz HWR cryomodule (designed and built at ANL) and a 325 MHZ SSR1 cryomodule (designed and built at FNAL). In this paper we present the recent advances in the development of the SSR1 resonators at Fermilab. Several bare SSR1 resonators have been processed, heat-treated and tested successfully in the Fermilab Vertical Test Stand. The outfitting of helium vessels is in process and the coarse-fine frequency tuning system has been designed and is currently being procured and tested. Details of the power coupler are also discussed.  
 
WEPWO057 Update of SSR2 Cavities Design for Project X and RISP cavity, linac, simulation, heavy-ion 2435
 
  • M. Merio, M.H. Awida, P. Berrutti, I.V. Gonin, T.N. Khabiboulline, D. Passarelli, Y.M. Pischalnikov, L. Ristori, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
  
  Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy.
Single spoke resonators SSR2 (f=325 MHz) are under development at Fermilab. These cavities can meet requirements of Project X (FNAL) and RISP (Korea). The initial design of SSR2 cavities has been modified and optimized in order to satisfy the necessities of both projects. This paper will discuss the RF optimization for a single spoke resonator with a 50 mm beam pipe aperture and an optimal beta of 0.51. Further, the approach to the mechanical design of the cavity will be presented together with the proposed helium vessel. The latter is intended to guarantee a low He pressure sensitivity df/dp of the entire jacketed SSR2 and actively control the microphonics. 		 
 
WEPWO058 Recent Progress at Fermilab Controlling Lorentz Force Detuning and Microphonics in Superconducting Cavities cavity, resonance, controls, SRF 2438
 
  • W. Schappert, Y.M. Pischalnikov
    Fermilab, Batavia, USA
  
  Funding: Work is supported by U.S. Department of Energy
SRF cavities are susceptible to detuning by mechanical deformations induced by the Lorentz force and microphonics. Providing the RF overhead required to maintain the accelerating gradient in detuned cavities can increase both the capital and operating costs of superconducting accelerators. Recent work at Fermilab has shown that active vibration control using a piezo actuator can reduce both Lorentz Force detuning and microphonics to the point where negligible RF overhead is required to maintain the accelerating gradient. 		 
 
WEPWO059 Cornell's HOM Beamline Absorbers HOM, linac, cavity, damping 2441
 
  • R. Eichhorn, J.V. Conway, Y. He, G.H. Hoffstaetter, M. Liepe, T.I. O'Connell, P. Quigley, J. Sears, V.D. Shemelin, N.R.A. Valles
    CLASSE, Ithaca, New York, USA
  
  The proposed energy recovery linac at Cornell aims for high beam currents and short bunch lengths, the combination of which requires efficient damping of the higher order modes (HOMs) being present in the superconducting cavities. Numerical simulations show that the expected HOM power could be as high as 200 W per cavity with frequencies ranging to 40 GHz. Consequently, a beam line absorber approach was chosen. We will review the design, report on first results from a prototype and discuss further improvements.  
 
WEPWO068 Cornell ERL Main Linac 7-cell Cavity Performance in Horizontal Test Cryomodule Qualifications cavity, linac, higher-order-mode, HOM 2459
 
  • N.R.A. Valles, R. Eichhorn, F. Furuta, G.M. Ge, D. Gonnella, Y. He, K.M.V. Ho, G.H. Hoffstaetter, M. Liepe, T.I. O'Connell, S. Posen, P. Quigley, J. Sears, V. Veshcherevich
    CLASSE, Ithaca, New York, USA
  
  Funding: NSF DMR-0807731
Cornell has recently finished producing and testing the first prototype 7-cell main linac cavity for the Cornell Energy Recovery Linac, and completed the prototype cavity qualification program. This paper presents quality factor results from the horizontal test cryomodule (HTC) measurements, from the HTC-1 through HTC-3 experiments, reaching Q's up to 6 x 1010 at 1.6 K. We investigate the effect of thermal cycling on cavity quality factor and show that high quality factors can be preserved from initial mounting to fully outfitting the cavity with side-mounted input coupler and beam line absorbers. We also discuss the production of six additional main-linac cavities as we progress toward constructing a full 6-cavity cryomodule. 		 
 
WEPWO069 HOM Studies of the Cornell ERL Main Linac Cavity: HTC-1 Through HTC-3 HOM, cavity, linac, higher-order-mode 2462
 
  • N.R.A. Valles, R. Eichhorn, G.H. Hoffstaetter, M. Liepe
    CLASSE, Ithaca, New York, USA
  
  Funding: Supported by NSF grant DMR-0807731
The Cornell energy recovery linac is designed to run a high energy (5 GeV), high current (100 mA), very low emittance beam (30 pm at 77 pC bunch charge). A major challenge to running such a large current continuously through the machine is the effect of strong higher-order modes(HOMs) that can lead to beam breakup. This paper presents the results of HOM studies for the prototype 7-cell cavity installed in a horizontal test cryomodule (HTC) from initial RF test, to being fully outfitted with side-mounted input coupler and beam line absorbers. We compare the simulated results of the optimized cavity geometry with measurements from all three HTC experiments. 		 
 
WEPWO073 RF Design Optimization for New Injector Cryounit at CEBAF cavity, coupling, SRF, injection 2471
 
  • H. Wang, G. Cheng, F.E. Hannon, A.S. Hofler, R. Kazimi, J.P. Preble, R.A. Rimmer
    JLAB, Newport News, Virginia, USA
  
  Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
A new injector superconducting RF (SRF) cryounit with one new 2-cell, β=0.6 cavity plus one refurbished 7-cell, β=0.97, C100 style cavity has been re-designed and optimized for the engineering compatibility of existing module for CEBAF operation. The optimization of 2-cell cavity shape for longitudinal beam dynamic of acceleration from 200keV to 533keV and the minimization of transverse kick due to the waveguide couplers to less than 1 mrad have been considered. Operating at 1497MHz, two cavities has been designed into a same footprint of CEBAF original quarter cryomodule to deliver an injection beam energy of 5MeV in less than 0.27o rms bench length and a maximum energy spread of 5keV.

 
 
WEPFI076 Experience with a 5 kW, 1.3 GHz Solid State Amplifier linac, status, SRF, factory 2869
 
  • K.M.V. Ho, R. Eichhorn, D.L. Hartill, M. Liepe
    CLASSE, Ithaca, New York, USA
  
  This study describes the experience with and performance of a commercially available 1.3 GHz 5kW Solid State Amplifier in various experiments at Cornell University. This paper focuses on several key factors in testing the performance of the amplifier. Among those are phase and amplitude stability, gain linearity, and phase shift vs. power. High power amplifiers are usually built with multiple RF power modules and the individual output signals are then combined in a power combiner. Therefore, the phases of the individual RF output power signals have to be adjusted within tight tolerances. The relative phases can be affected by different lengths cables and also affect the overall gain performance of the amplifier.  
 
WEPME052 LLRF Characterisation of the Daresbury International Cryomodule LLRF, cavity, resonance, SRF 3046
 
  • L. Ma
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  • P.A. Corlett, A.J. Moss
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  
  The 2-cavity Superconducting RF (SRF) Linac cryomodule of the Accelerators and Lasers in Combined Experiments (ALICE) located at Daresbury Laboratory will be replaced by a new International ERL Cryomodule in early 2013. The improved 7-cell, 1.3 GHz SRF cavities will be characterised and compared with the original 9-cell cavities. Tests will be performed by driving the cavities by a VCO-PLL loop so that Q measurements, microphonics sensitivity and Lorentz force detuning can be analysed. A digital LLRF system using the LLRF4 board developed by Larry Doolittle has been developed at Daresbury Laboratory and will be installed on the upgraded cryomodule. This system is capable of controlled cavity filling to reduce waveguide reflection voltage, feedback/feed forward control and adaptive beam loading compensation. The new cryomodule will be evaluated with both the analog LLRF system and the digital LLRF system to allow for performance comparison. Cavity operation with high QL will also be tested to discover the feedback control limit as a function of inherent microphonics. This paper sets out to discuss the qualification process, testing and results of the upgraded cryomodule installation.  
 
WEPME057 Commission of the Drive Laser System for Advanced Superconducting Test Accelerator laser, gun, controls, monitoring 3061
 
  • J. Ruan, M.D. Church, D.R. Edstrom, Jr, T.R. Johnson, J.K. Santucci
    Fermilab, Batavia, USA
  
  Currently an advanced superconducting test accelerator (ASTA) is being built at Fermilab. The accelerator will consist of a photo electron gun, injector, ILC-type cryomodules, multiple downstream beam lines for testing cryomodules and carrying advanced accelerator researches. In this paper we will report the commissioning and the drive laser system for this facility. It consists of a fiber laser system properly locked to the master frequency, a regen-amplifier, several power amplifier and final wavelength conversion stage. We will also report the characterization of the whole laser system and the performance of the laser system.  
 
WEPME058 Integrated System Modeling Analysis of a Multi-cell Deflecting-mode Cavity in Cryogenic Operation cavity, simulation, vacuum, coupling 3064
 
  • Y.-M. Shin, M.D. Church, J. Ruan
    Fermilab, Batavia, USA
  
  Over the past decade, multi-cell deflecting (TM110) mode cavities have been employed for experiments on six-dimensional phase-space beam manipulation *,**,***,****,****** at the A0 Photo-Injector Lab (16 MeV) in Fermilab and their extended applications with vacuum cryomodules are currently scheduled at the Advanced Superconducting Test Accelerator (ASTA) user facility (> 50 MeV). Despite the successful test results, the cavity, however, demonstrated limited RF performance during liquid nitrogen (LN2) ambient operation that was inferior to theoretic prediction. We thus fully inspected the cavity design with theoretical calculation (based on Panofsky-Wenzel theorem) combined with RF simulations. Also, we are extensively developing an integrated computational tool with comprehensive system analysis capacity to solve complex thermodynamics and mechanical stresses of a high-Q deflecting-mode cryomodule. We will benchmark simulation analysis result with experimental data from high power RF tests in Fermilab. Successfully developed modeling tool will be potentially used for prompt assessment on RF performance of vacuum-cryomodules.
* D. A. Edwards, LINAC 2002
** Y.-E Sun, PRTAB 2004
*** P. Piot, PRSTAB2006
**** J. Ruand et al., PRL 2011
***** Y.-E. Sun, et al., PRL 2010
 		 
 
THYB201 Where Next with SRF? SRF, linac, cavity, proton 3124
 
  • G. Ciovati
    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.
RF superconductivity (SRF) has become, over the last ~20 years, the technology of choice to produce RF cavities for particle accelerators. This occurred because of improvements in material and processing techniques as well as the understanding and remediation of practical limitations in SRF cavities. This development effort span ~40 years and Nb has been the material of choice for SRF cavity production. As the performances of SRF Nb cavities are approaching what are considered to be theoretical limits of the material, it is legitimate to ask what will be the future of SRF. In this article we will attempt to answer such question on the basis of near-future demands for SRF-based accelerators and the basic SRF properties of the available materials. Clearly, Nb will continue to play a major role in SRF cavities in the coming years but the use of superconductors with higher critical temperature than Nb is also likely to occur. 		 
slides icon Slides THYB201 [1.549 MB]  
 
THPFI003 Vacuum Study of the Cavity String for the IFMIF - LIPAc Cryomodule vacuum, cavity, pick-up, linac 3291
 
  • N. Bazin, G. Devanz, F. Orsini
    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. This paper will focus on the beam vacuum of the cryomodule. The cryomodule beam line is made of the pattern solenoid package / cavity-coupler, and a valve on each side of the cryomodule. During the installation of the cryomodule on the accelerator system, the cavity string has to be pumped down with the beam valves closed. Thereby a manifold is connected to the cavities during the assembly of the beam line components in the clean room. In previous conferences, the cryomodule was presented with a vacuum manifold connected to each cavity. A study realized on this complex vacuum configuration with Molflow, a test-particle Monte-Carlo simulator for ultra-high vacuum, permitted to reduce the number of cavities connected to the manifold and by consequence to reduce the risk of pollution during the clean room assembly.  
 
THPFI004 Progress on the SRF Linac Developments for the IFMIF-LIPAC Project solenoid, linac, vacuum, SRF 3294
 
  • F. Orsini
    CEA/DSM/IRFU, France
  • P. Abramian, J. Calero, J.C. Calvo, J.L. Gutiérrez, T. Martínez de Alvaro, J. Munilla, I. Podadera, F. Toral
    CIEMAT, Madrid, Spain
  • N. Bazin, P. Brédy, P. Carbonnier, G. Devanz, G. Disset, N. Grouas, P. Hardy, V.M. Hennion, H. Jenhani, J. Migne, A. Mohamed, J. Neyret, J. Relland, B. Renard, D. Roudier
    CEA/IRFU, Gif-sur-Yvette, France
  
  In the framework of the International Fusion Materials Irradiation Facility (IFMIF), which consists of two high power accelerator drivers, each delivering a 125 mA deuteron beam at 40 MeV in CW, an accelerator prototype is presently under design and realization for the first phase of the project. This accelerator includes a SRF Linac, which is designed for the transportation and focalization of the deuteron beam up to 9 MeV. This SRF Linac is a large cryomodule of ~6 m long, working at 4.4 K and at the frequency of 175 MHz in continuous wave. It is mainly composed of 8 low-beta HWRs, 8 Solenoid Packages and 8 RF Power Couplers. This paper focuses on the recent developments and changes made on the SRF Linac design: following the abandon of the HWR frequency tuning system, initially based on a plunger located inside the central region of the resonator, a new external tuning system has been designed, implying a complete redesign of the resonator and consequently impacting the cryomodule lattice. The recent changes in the design are presented in this paper. In addition, cold tests were performed on a HWR prototype and cold tests results of the magnets prototypes are also presented.  
 
THPME010 Magnetic Shielding for the 1.3 GHz Cryomodule at IHEP shielding, simulation, cavity, SRF 3528
 
  • S. Jin, Y. Chen, J. Gao, R. Ge, Y. Liu, Z.C. Liu, J.Y. Zhai, T.X. Zhao, H.J. Zheng
    IHEP, Beijing, People's Republic of China
  • F. Yang
    China Iron and Steel Research Institute Group, Beijing, People's Republic of China
  
  An ILC-type Superconducting RF (SRF) accelerating unit is being studied at IHEP. In order to achieve the design performance including both accelerating gradient and quality factor, the SRF cavity must be cooled with ambient magnetic field well shielded to the level of several mG[1,2]. In this paper, permeability of several kinds of materials for magnetic shielding made in China is systematically studied in cooperation with China Iron & Steel Research Institute Group (CISRI) and reported for the first time. By using proper material, numerical calculation for the magnetic shielding design was done via the program of Opera-3D, and then magnetic shield was fabricated by CISRI. This paper will show those studies above and the final magnetic shielding effect at room temperature. Comparisons between simulation result and real effect will also be discussed in the paper, as well as the preliminary analysis for the magnetic field leaking of this design.  
 
THPME019 Design of the Cold Mass Support Assembly of Test Cryomodule for IMP ADS-Injector II solenoid, cavity, controls, vacuum 3543
 
  • Y. Liu, S. Sun, J. Wang, L. Wang, S.Y. Wang
    SINAP, Shanghai, People's Republic of China
  • X.L. Guo
    JiangShu University, Jiangsu Province, People's Republic of China
  
  In order to test the performance of the HWR cavities and verify the related technique for cooling of the cavities and the solenoids together, a test cryomodule (TCM1) containing one superconducting HWR cavity followed by one cold BPM and two superconducting solenoids was developed for the Injector II of the Accelerator Driven Sub-critical System (ADS). The TCM1 consists of the cryostat and the cold mass assembly. The cryostat is composed of vacuum chamber, thermal shields, cooling circuit, cold mass support assembly, and instrumentation. A set of cold mass support assembly was developed for supporting the cold mass working at 4.4 K. The support assembly mainly consists of Ti support frame, stainless steel rods, adjustable mechanisms and LHe cooling passage. It can not only support the weight of the cold mass but also stand the thermal stress during the cool down. In order not to affect the performance of the cavity, it will not impose any force on the HWR cavity. It can be adjustable for alignment of the cold mass both at room temperature and 4.4 K. This paper provides the detailed design of the TCM1 cold mass support assembly.  
 
THPME020 Design of a Test Cryomodule for IMP ADS-Injector II cavity, solenoid, vacuum, radiation 3546
 
  • L. Wang, Y. Liu, S. Sun, J. Wang, S.Y. Wang, S.H. Wang
    SINAP, Shanghai, People's Republic of China
  • X.L. Guo
    JiangShu University, Jiangsu Province, People's Republic of China
  
  Two cryomodules are to be applied for the Injector II of the Accelerator Driven Sub-critical System. Each of them will contain 8 superconducting HWR cavities and 9 superconducting solenoids. In order to test the performance of the HWR cavities and validate related technique for cooling of cavities and solenoids together, a test cryomodule (TCM1) including one HWR cavity and two solenoids was developed. The design of the TCM1 cryostat was carried out by the Shanghai Institute of Applied Physics, CAS. Both the cavity and the solenoids will work at 4.4 K by bath cooling. The fast cooling down for the cavity from 100 K to 120 K is required to avoid degrading of the cavity performance. Before energization, the solenoids can be warmed up to above 10 K and re-cooled down for degaussing. The TCM1 can not only be cooled by using the dewar-filling system, but also operated by the refrigerator system. The main components of the cryostat include vacuum chamber, thermal shields, magnet current leads, cooling circuit, and cold mass support assembly. This paper presents the detailed design of the TCM1 cryostat.  
 
THPME025 Design of Cryomodules for RAON cryogenics, cavity, linac, vacuum 3558
 
  • Y. Kim, C. Choi, D. Jeon, H.J. Kim, M. Lee
    IBS, Daejeon, Republic of Korea
  
  The RAON linac utilizes four types of superconducting cavities such as QWR, HWR, SSR1, and SSR2 which are operating at 2 K in order to accelerate the various ion beams. The main role of the cryomodules is to maintain the cryogenic temperature for the superconducting cavity operation. Five types of cryomodules will be necessary since one QWR cavity, three and six HWR cavities, four SSR1 cavities, and eight SSR2 cavities will be installed in the dedicated cryomdoules. Total number of the cryomodule is 147, 48 for QWR, 60 for HWR, 22 for SSR1, 17 for SSR2. The cryomodules of RAON does not include focusing magnets but includes the cavities operating at 2 K. This paper describes the current status of the RAON cryomodule design. The issues included in the paper are the thermal load estimation, design of the components such as thermal shield and intercept of the cryomodules, and cryogenic flow circulation system according to the cryomodule operation.  
 
THPWO001 Assembling, Testing and Installing the SPIRAL2 Superconducting Linac linac, vacuum, cavity, alignment 3752
 
  • P.-E. Bernaudin, R. Ferdinand
    GANIL, Caen, France
  • P. Bosland
    CEA/DSM/IRFU, France
  • Y. Gomez Martinez
    LPSC, Grenoble, France
  • G. Olry
    IPN, Orsay, France
  
  Assembly and tests of the SPIRAL2 superconducting linac's components are now proceeding smoothly. Cryomodules are being processed in CEA Saclay and IPN Orsay, inter-cryomodules "warm" sections in GANIL. While installation of the accelerators components is going on in the new SPIRAL2 building in Caen, installation of the cryomodules will begin during the last quarter of 2013. The latest results of the cryomodules tests as well as the installation strategy are depicted in this paper.  
 
THPWO016 Superconducting CH Cavities for Heavy Ion Acceleration cavity, linac, solenoid, status 3794
 
  • F.D. Dziuba, M. Amberg, M. Busch, H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • M. Amberg, K. Aulenbacher, W.A. Barth, S. Mickat
    HIM, Mainz, Germany
  • K. Aulenbacher
    IKP, Mainz, Germany
  • W.A. Barth, S. Mickat
    GSI, Darmstadt, Germany
  
  Funding: Work supported by HIM, GSI and BMBF Contr. No. 06FY7102
To demonstrate the operation ability of superconducting (sc) Crossbar-H-mode (CH) cavity technology a 217 MHz structure of this type is under development at the Institute for Applied Physics (IAP) of Frankfurt University. The cavity has 15 accelerating cells and a design beta of 0.059. It will be equipped with all necessary auxiliaries like a 10 kW power coupler and a tuning system. Currently, the cavity is under construction. Furthermore, this cavity will serve as demonstrator for a sc continuous wave (cw) LINAC at GSI. The proposed cw LINAC is highly requested to fulfil the requirements of nuclear chemistry and especially for a competitive production of new Super Heavy Elements (SHE) in the future. A full performance test by injecting and accelerating a beam from the GSI High Charge Injector (HLI) is planned in 2014. The current status of the sc CH cavity and the demonstrator project is presented. 		 
 
THPWO064 Superconducting Linac for the Rare Isotope Science Project linac, cavity, ion, quadrupole 3903
 
  • H.J. Kim, H.J. Cha, M.O. Hyun, H.J. Jang, D. Jeon, J.D. Joo, M.J. Joung, H.C. Jung, Y.C. Jung, Y. Kim, M. Lee, G.-T. Park
    IBS, Daejeon, Republic of Korea
  
  Abstract The RISP (Rare Isotope Science Project) accelerator has been planned to study heavy ion of nuclear, material and medical science at the Institute for Basic Science (IBS). It can deliver ions from proton to Uranium. The facility consists of three superconducting linacs of which superconducting cavities are independently phased and operating at three different frequencies, namely 81.25, 162.5 and 325 MHz. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the RISP linac design, the superconducting cavity and the requirements of beam diagnosics.  
 
THPWO072 Design Options of the ESS Linac linac, emittance, target, proton 3921
 
  • M. Eshraqi, H. Danared, D.P. McGinnis
    ESS, Lund, Sweden
  
  The European Spallation Source, ESS, uses a linear accelerator to deliver the high intensity proton beam to the target station. The nominal average beam power is 5~MW with a peak beam power at target of 125~MW. During last year the ESS linac was costed, and to meet the budget a few modifications were introduced to the linac design, namely the final energy was decreased from 2.5~GeV to 2.0~GeV and the beam current was increased accordingly to compensate the lower final energy. As a result the linac is designed to meet the cost objective by taking a higher risk. This paper focuses on the new design options, beam dynamics requirements of the design and finally on the beam dynamics performance of the linac.  
 
THPWO092 Update of Beam Optics and SRF Cavities for Project X linac, cavity, solenoid, optics 3975
 
  • T.N. Khabiboulline, P. Berrutti, V.A. Lebedev, A. Lunin, T.H. Nicol, J.-F. Ostiguy, T.J. Peterson, L. Ristori, A. Saini, N. Solyak, V.P. Yakovlev
    Fermilab, Batavia, USA
  
  The Project X staging [1] requires reconsideration of the beam optics and thus, the SRF system for the 3 GeV CW linac of the Project X. The revised beam optics is presented in the paper as well as revised cavity design for SSR2 section and a new concept of the linac segmentation. The new versions for the Project X cryo-modules for the SSR2 section, low-beta 650 MHz section and high-beta 650 MHz section are discussed. The beam extraction scheme at 1 GeV is discussed also. [1] S. Holmes, “Project X News, Strategy, Meeting Goals,” 2012 Fall Project X Collaboration Meeting, 27-28 November 2012, Fermilab.