Technology
RF power sources and power couplers
Paper Title Page
WE1A04 The High Power RF System for the European XFEL 601
 
  • S. Choroba
    DESY, Hamburg, Germany
 
  The presentation will be on the design, construction and commissioning of the high power RF system for the European XFEL. The RF system consists of 26 high power RF stations each capable of 10MW RF pulse power. It will report on the overall system layout, cover RF system components e.g. klystrons, modulators and high power RF waveguide distribution. It will also cover system modifications during construction phase and report on commissioning results.  
slides icon Slides WE1A04 [12.620 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-WE1A04  
About • paper received ※ 17 September 2018      issue date ※ 18 January 2019  
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THPO090 The Analysis of Module Failure in High Solid-state Amplifier for High Current RFQ 886
 
  • L.P. Sun, Y. He, G. Huang, C.X. Li, L. Lu, A. Shi, L.B. Shi, X.B. Xu, H.W. Zhao
    IMP/CAS, Lanzhou, People’s Republic of China
 
  New accelerator RF system was upgraded to the solid-state amplifier in ADS project due to its stable, sustainable and reliable. Until now, newest 80kW SSA was adopted in IMP, operating in 162.5MHz, and over 120 power modules were combined through several synthesizers for 80kW output. but since too many modules were optimized for amplitude and phase in the same time, one or some failure of circulator will lead to injure of whole RF system, when wavelength meets a specific condition, injure would turn out severe accident and heavy loss. In this paper, analyzing and simulating the multi-level synthetic matrix was the important method for ADS accident happened in June 20. 2017, the failure simulated results for RF amplify links under the specific circumstances also was presented simultaneously.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO090  
About • paper received ※ 17 September 2018      issue date ※ 18 January 2019  
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THPO091 90 kW Solid-state RF Amplifier with a TE011-mode Cavity Power-combiner at 476 MHz 889
THOP07   use link to see paper's listing under its alternate paper code  
 
  • Y. Otake, T. Asaka, T. Inagaki
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • S. Aizawa, K. Nagatsuka, T. Okuyama, K. Sato, H. Yamada
    Nihon Koshuha Co. Ltd, Yokohama, Japan
 
  Solid-state RF amplifiers, which have long lifetimes and small failures, are the recent trend of reliable and stable high-power rf sources for particle accelerators. Hence, we designed a 90kW solid-state amplifier with an extreme low-loss TE011 mode cavity (Q0=100, 000) power-combiner operated at 476 MHz and a 6 us pulse width. Developing this amplifier is for replacement of an IOT rf amplifier, at the X-ray free-electron laser, SACLA. In SACLA, highly RF phase and amplitude stabilities of less than 0.02 deg. and 10-4 in rms are necessary to stable lasing within a 10 % intensity fluctuation. The amplifier comprises a drive amplifier, a reentrant cavity rf power divider, 100 final amplifiers with a 1 kW output each and a TE011 mode cavity combiner. Water-cooling within 10 mK and a DC power supply with a noise of less than -100 dBV at 10 Hz for the amplifier is necessary to realize the previously mentioned stabilities. Based on the test results of the amplifier, the above-mentioned specifications with the extreme low-loss are promising. The amplifier also allows us to operate in pulsed and CW rfs for linacs and ring accelerators. We report the performance of the 90kW amplifier.  
slides icon Slides THPO091 [1.750 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO091  
About • paper received ※ 06 September 2018      issue date ※ 18 January 2019  
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THPO092 LCLSII Fundamental Power Coupler Manufacturing Status and Lesson Learned 893
 
  • S. Sierra, G. Garcin, Ch.L. Lievin, G. Vignette, I. Yao Leclerc
    TED, Velizy-Villacoublay, France
  • M. Knaak, M. Pekeler
    RI Research Instruments GmbH, Bergisch Gladbach, Germany
 
  Thales and RI Research Instrument have manufactured and assembled half of the power couplers for the LCLSII project. This paper remains main characteristics of these coupler. It will also describe main challenges that were overcome among them, thickness of copper coating on Warm Internal Conductor at 150µm and lessons learned during the manufacturing phase of these couplers. The paper will also propose some possible optimization for a future mass production of such components and parameters which could be relevant for a better understanding link to the statistic results obtained.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO092  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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THPO093 Status and Results Obtained on a RF Conditioning Test Bench for 704 MHz Couplers in the Frame of ESS Project 895
 
  • S. Sierra, Y. Amal, Ch.L. Lievin, I. Yao Leclerc
    TED, Velizy-Villacoublay, France
  • M.E. Chahbazian, J.G. DeOliveira, A.G. Goeury, L.J. Nennig, S.P. Petitjean
    GERAC Thales, Le Barp, France
 
  Thales and Gerac are developing a test bench able to make the RF conditioning of the Fundamental Power Couplers at 704 MHz in the frame of the ESS project for CEA. The status of the developments of the test bench is described including the modulator, klystron and all relative equipments. The paper will also describes the results obtained at the date of presentation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO093  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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THPO095 Present Status of Capacitor-charging Power Supplies for Klystron Modulators in SuperKEKB Injector Linac 898
 
  • M. Kawamura, M. Akemoto, S. Fukuda, H. Honma, S. Michizono, H. Nakajima, T. Natsui, T. Shidara
    KEK, Ibaraki, Japan
  • H. Akikawa, O. Endo, K. Sato
    Nihon Koshuha Co. Ltd, Yokohama, Japan
 
  The capacitor-charging power supplies (CCPSs) for the klystron modulators have been developed from 2002 in the SuperKEKB injector linac. The specifications are that the output voltage is 43kV, the charging power is 30kJ/s, and the output voltage stability is 0.2%p-p. Being used in the old facility, their sizes are restricted in 480mm x 680 mm x 760mm. After various modifications, the 13 CCPSs in the linac have been operated with no fault since last October. The present status of the CCPSs, including the outlines, specifications, and the modifications against the faults, are described.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO095  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO096 Design Study of a High Efficiency Klystron for SuperKEKB Linac 901
 
  • F. Qiu, S. Fukuda, S. Matsumoto, T. Matsumoto, T. Miura, T. Natsui
    KEK, Ibaraki, Japan
 
  The injector linear accelerator (linac) for the SuperKEKB particle accelerator requires a higher efficiency klystron than the currently used 50 MW, S-band, pulsed unit (PV3050/E3730), which operates at the same voltage, to increase the power redundancy. The efficiency is expected to improve from the currently observed 45% to more than 60%. We propose a type of high efficiency klystron using novel bunching mechanisms. The 1-D disk model based code is used for preliminary optimization of the tube parameters; these parameters are further checked by 2-D codes known as field charge interaction (FCI) and MAGIC. In this paper, the design consideration of the high efficiency klystron is presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO096  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO097 Recent Results for Study of Ceramic and Copper Plating for Power Couplers 905
 
  • Y. Yamamoto, E. Kako, S. Michizono
    KEK, Ibaraki, Japan
  • E. Cenni
    CEA/IRFU, Gif-sur-Yvette, France
  • A. Four
    CEA/DRF/IRFU, Gif-sur-Yvette, France
  • Y. Okii
    Nomura Plating Co, Ltd., Osaka, Japan
 
  KEK has conducted a survey to select an optimum ceramic after withdrawal by a domestic manufacturing company two years ago. For this selection, there are four important items on the properties of ceramic; that is, relative permittivity, dielectric loss tangent, surface and volume resistance, and secondary electron emission coefficient. For measurements of these parameters, five kinds of ceramic samples supplied from three companies were measured using three kinds of measurement systems. For measurement of secondary electron emission, scanning electron microscope (SEM) with beam blanking system was used. On the other hand, residual resistivity ratio (RRR) for copper plating, which is the most important item for quality control, has also been carried out while changing plating thickness and acid temperature. In this report, the recent results for these studies will be presented in detailed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO097  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO100 Development of a 1.5 GHz High-power CW Magnetron for SRF Accelerator 908
 
  • L. Wenliang
    College of Engineering and Applied Sciences for Nanjing University, Nanjing, People’s Republic of China
  • S. An, Y.J. Ke, S. Lingbin, Z. Pengjiao, L. Youchun, L. Zhao, B.Z. Zhou
    PLAI, Nanjing, People’s Republic of China
  • J.Z. Li, L.P. Zhang, Hou, R. Rui
    ADS, Jiangsu Province, People’s Republic of China
 
  An 1.5 GHz, 13.5 kW CW high-power magnetron for a superconducting RF accelerator has been developed by Andesun Technology Group Co., Ltd. with Nanjing Sanle Electronic Information Industry Group Co., Ltd., in order to replace the klystron, that could reduce the power source cost to about one-third. The cavity, output power antenna and coupling door-nob have been optimized by using CST Studio. Testing results have shown that the resonance frequency and output power have met the requirements, and the efficiency of the magnetron is higher that 78.45%.  
poster icon Poster THPO100 [0.574 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO100  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO102 Design Studies of Output Window for CEPC Klystron 911
 
  • Z.J. Lu, Y.L. Chi, S. Fukuda, G. Pei, S. Pei, S.C. Wang, O. Xiao, U. N. Zaib, Z.S. Zhou
    IHEP, Beijing, People’s Republic of China
  • S. Fukuda
    KEK, Ibaraki, Japan
 
  A high power and high efficiency klystron of the 650MHz, 800kW CW klystron for the Circular Electron Positron Collider (CEPC) is designed and developed at IHEP. This paper presents the design and simulation for the high power coaxial window for it. Plan of the hot test (high power testing before installing to the klystron) are also described. Simulation software of CST, ANSYS and Multipac 2.1 are used for design of window microwave structure, thermal analysis and multipacting effects. We obtained the good simulation results successively; the coaxial window S-parameter analysis, has revealed a low reflection at the operating frequency of 650 MHz. The thermal simulation shows a good temperature distribution under the cw 800kW propagation; maximum temperature has been found to be 33 °C at ceramic with water cooling in the inner and outer conductor. The multipacting at the window is possible source of the failure and it is shown that multipacting has less chance to be happened on the surface of ceramic.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO102  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO103 Application of Solid State Amplifiers in ADS Project at IHEP 914
 
  • O. Xiao
    Institute of High Energy Physics (IHEP), People’s Republic of China
  • Y.L. Chi, N. Gan, X. Ma, Z.S. Zhou
    IHEP, Beijing, People’s Republic of China
 
  The solid state amplifier is an important part of the RF power source system of ADS project at IHEP. Three kinds of solid state amplifier with different power and frequency have been applied. In this paper, the specifications of solid state amplifier are presented. In addition, the principle of breakdown of power modules during the high power test of coupler are analyzed.  
poster icon Poster THPO103 [0.195 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO103  
About • paper received ※ 17 September 2018      issue date ※ 18 January 2019  
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THPO104 Development of 150.4MHz Continuous Wave Solid-state Amplifier 917
 
  • L. Zhao
    Nanjing University of Aeronautics and Astronautics, Jiangning, People’s Republic of China
  • S. An, Y.J. Ke, Z. Pengjiao, L. Wenliang, B.Z. Zhou
    PLAI, Nanjing, People’s Republic of China
 
  A 150.4MHz to 155.4MHz, 300W continuous wave solid-state amplifier as an accelerator power source has been developed by us. In order to increase the lifetime of MOSFET and meet the requirements of every parameters, Drain voltage and quiescent current is set at a better point with a well-designed heat dissipation structure, we make the solid state amplifier stable in performance. Taking the microwave leakage into account, the chassis structure is optimized and designed, and the microwave absorption device is adopted to make the structure compact, protect other parts not affected by the microwave leakage. After the assembly is completed, the working parameters meet the design requirements very well. The MOSFET flange temperature and output parameters meet the design requirements.  
poster icon Poster THPO104 [1.405 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO104  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO107 High Power Coupler R&D for Superconducting CH-cavities 920
SPWR025   use link to see paper's listing under its alternate paper code  
 
  • J. List, K. Aulenbacher, W.A. Barth, F.D. Dziuba, V. Gettmann, T. Kürzeder, M. Miski-Oglu
    HIM, Mainz, Germany
  • K. Aulenbacher
    IKP, Mainz, Germany
  • W.A. Barth, M. Heilmann, J. Salvatore, A. Schnase, S. Yaramyshev
    GSI, Darmstadt, Germany
  • M. Basten, M. Busch, H. Podlech, M. Schwarz
    IAP, Frankfurt am Main, Germany
 
  The upcoming demands of the future research programs at GSI exceed the technical opportunities of the existing UNIversal Linear ACcelerator (UNILAC). Besides, the machine will be exclusively used as an injector for FAIR (Facility for Antiproton and Ion Research) providing high power heavy ion beams at a low repetition rate for injection into the synchrotron. A new dedicated superconducting (sc) continuous wave (cw) Linac is crucial to keep the research program competitive. The first part of the cw-linac, comprising a 217 MHz multi gap Crossbar-H-mode (CH) cavity surrounded by two sc solenoids inside a cryostat, already served as a prototype demonstrating reliable operability in a realistic accelerator environment. A sufficient high power RF-coupling concept is needed to feed this newly developed cw-RF cavity with up to 5 kW of RF-power. A high power coupler test stand was recently built to provide for a testing environment; further upgrade measures of this test area are foreseen. This contribution deals with the recent coupler R&D for the demonstrator set up. Besides simulations of thermal losses at the coupler (inside the RF-cavity) will be shown as well.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO107  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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