Keyword: controls
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MO1P03 Status of the ESS Linac linac, cavity, ion-source, target 35
 
  • A. Sunesson, P. Arnold, S.L. Birch, R. Garoby, M. Jensen, M. Lindroos, C.A. Martins, A. Nordt, T.J. Shea, J.G. Weisend
    ESS, Lund, Sweden
 
  The European Spallation Source under construction in Lund (Sweden) uses a 2 GeV-5MW pulsed superconducting linac as proton driver. Normal conducting accelerating structures are used up to 92 MeV and superconducting structures up to 2 GeV. Most linac components are designed and procured as in-kind contributions by institutes/laboratories in the European partner countries. Installation of the Ion source delivered by INFN-Catania started end 2017. Installation of more components and infrastructure progresses at a high pace. Commissioning of the normal conducting linac section will take place in parallel with installation of the superconducting section. Beam commissioning of the superconducting section will be done starting in 2021, interlaced with the installation of additional high beta cryomodules. Beam will be sent to the target in 2022, initially at an energy of 1.3 GeV. Start of the User Programme is scheduled in 2023, when some neutron instruments will be ready and end of construction is in 2025, with the full set of instruments operational. This paper reports the status of linac components construction, the progress with installation on site, and the overall project schedule.  
slides icon Slides MO1P03 [14.161 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MO1P03  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO026 The Resonance Frequency Shift After Applying the Cooling System for a Side Coupled Standing Wave Linac cavity, electron, coupling, resonance 81
 
  • M. Mohseni Kejani, F. Abbasi Davani
    Shahid Beheshti University, Tehran, Iran
  • S. Ahmadiannamin
    ILSF, Tehran, Iran
  • F. Ghasemi
    NSTRI, Tehran, Iran
  • S. Zarei
    Nuclear Science and Technology Research, InstituteRadiation Application School, Tehran, Iran
 
  A radio frequency accelerator tube used in linear medical accelerators includes three main sections of the radio frequency cavity, an electron gun and the X-ray target, which is vacuumed by a pump inside it. The electromagnetic energy loss in the structure of the cavity can increase the temperature of the tube, resulting in changes in the geometric dimensions and then changes in some of the cavity characteristics, such as the resonance frequency. A cooling system is required to prevent excessive change in the resonant frequency due to thermal loss. Also, it is necessary to perform some computer simulations to stabilize the cavity’s performance in the presence of electromagnetic energy thermal dissipation and the cooling system. In this paper, the simulation results of resonant frequency shifts after applying the cooling system have been reported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO026  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO041 Performance Test Results of Magnet Power Supply FPGA, interface, power-supply, experiment 118
 
  • K.-H. Park, J.H. Han, S.-H. Jeong, Y.G. Jung, D.E. Kim, M.J. Kim, H.-G. Lee, S.B. Lee, B.G. Oh, H.S. Suh
    PAL, Pohang, Kyungbuk, Republic of Korea
 
  A high stable magnet power supply (MPS) was developed, which was a bipolar type with 200A of the output current at the 40V of output voltage. The MPS has been implemented by the digital signal processing technology using the DSP, FPGA, ADCs and so on. The output current stability of the MPS showed about 6ppm peak-to-peak in a short term experiment at 200A of its full output current. The long term stability was shown in 15 ppm peak-to-peak for 10 hours at 200A. And the others experimental results about the MPS were shown in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO041  
About • paper received ※ 31 August 2018      issue date ※ 18 January 2019  
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MOPO058 Industrial Electron Linear Accelerator R&D in CIAE electron, gun, radiation, linac 124
 
  • J.H. Yang, Y. Yang, G. Yu, Z.Q. Zeng
    CIAE, Beijing, People’s Republic of China
  • Z.B. Zhu
    China Institute of Atomic Energy, Beijing, People’s Republic of China
 
  Electron linear accelerator(E-LINAC)is a vital accelerator type for accelerator applications, which widely applied in industry, agriculture and medical industry. The paper introduces R&D of industrial E-LINAC in China Institute of Atomic Energy (CIAE) , including electron gun, modulator, accelerating tube, assembling and testing. Based on these R&D results, the GT series for non-destructive testing(NDT) and FZ series for irradiation processing are developed successfully. At present these E-LINACs play important roles in pressure vessel inspection, food preservation, sterilization and material modification, promoting the E-LINACs application as well as economic development in China.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO058  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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MOPO060 Linacs for Industry, Cargo Inspection and Medicine Designed by Moscow University electron, radiation, klystron, operation 130
 
  • A.N. Ermakov, A.S. Alimov, A.N. Kamanin, V.V. Khankin, L. Ovchinnikova, N.I. Pakhomov, N.V. Shvedunov, V.I. Shvedunov, D.S. Yurov
    SINP MSU, Moscow, Russia
  • A.S. Alimov, A.N. Ermakov, V.V. Khankin, L. Ovchinnikova, N.I. Pakhomov, N.V. Shvedunov, V.I. Shvedunov, A.S. Simonov
    LEA MSU, Moscow, Russia
  • I.V. Shvedunov
    Federal State Unitary Enterprise, Laboratory of Electron Accelerators MSU, Ltd, Moscow, Russia
 
  Funding: Work supported in part by Ministry of Education and Science of Russia Grant # RFMEFI58217X0011
The report presents the results of development of applied linear electron accelerators with an energy of up to 10 MeV, performed by the Laboratory of Electron Accelerators MSU. We describe linear accelerators for mobile, stationary and train cargo inspection systems with interlaced energies and pulse repetition rate up to 2 kHz, accelerators for radiography, a sterilization accelerator with beam parameters that are adjustable over a wide range, and an accelerator for a radiotherapy complex.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO060  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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MOPO061 Beam Parameters Measurement of C-band 6 MeV Linear Electron Accelerator gun, electron, radiation, klystron 133
 
  • D.S. Yurov, A.S. Alimov, A.N. Ermakov, V.V. Khankin, N.V. Shvedunov, V.I. Shvedunov
    SINP MSU, Moscow, Russia
  • L. Ovchinnikova
    Laboratory of Electron Accelerators MSU, Ltd, Physics Department, Lomonosov Moscow State University, Moscow, Russia
  • A.S. Simonov
    LEA MSU, Moscow, Russia
 
  The new linear electron accelerator with beam energy varied in the range of 2-6 MeV with dual-energy option has been designed by Laboratory of Electron Accelerators MSU Ltd. Linac is based on compact high gradient stand-ing wave C-band accelerating structure fed by multi-beam klystron and is used in the cargo inspection and cancer therapy complexes. In the report, we present the results of electron beam parameters measurements at special stand.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO061  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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MOPO062 Linear Electron Accelerator for Radiation Technologies with Beam Parameters Varied in a Wide Range electron, operation, radiation, gun 136
 
  • V.V. Khankin, A.S. Alimov, A.N. Ermakov, A.N. Kamanin, A. Kurilik, N.I. Pakhomov, N.V. Shvedunov, V.I. Shvedunov, D.S. Yurov
    SINP MSU, Moscow, Russia
  • A. Kurilik
    LEA MSU, Moscow, Russia
  • I.V. Shvedunov, A.S. Simonov
    Federal State Unitary Enterprise, Laboratory of Electron Accelerators MSU, Ltd, Moscow, Russia
 
  We present the overview and beam parameters measurements results as well as the operational experience with the S-band pulsed linear electron accelerator with beam energy in the range of 5-10 MeV and maximum beam power of up to 15 kW. The possibility of adjusting the beam parameters in a wide range, provided by the design and control system of the accelerator, allows to use the accelerator in a wide variety of radiation technologies.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO062  
About • paper received ※ 07 September 2018      issue date ※ 18 January 2019  
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MOPO076 Study on Generation of Variable Polarized Coherent THz Radiation Using a Crossed Undulator undulator, radiation, polarization, electron 157
 
  • H. Saito, H. Hama, F. Hinode, K. Kanomata, S. Kashiwagi, S. Miura, T. Muto, I. Nagasawa, K. Nanbu, S. Ninomiya, K. Takahashi
    Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
 
  A variable polarized THz radiation source using a crossed undulator system has been developed at Tohoku University. In this scheme, two coherent undulator radiations from an extremely short electron bunch are used to control the polarization. They are linearly polarized radiations orthogonal to each other. Polarization of superimposed radiation is controlled by adjusting a relative phase between them. A compact planar undulator with seven periods has been designed for an experiment at our facility. The radiation frequency is 2.06 THz for electron beam energy of 22 MeV. The opening angle of the crossed undulator radiation was estimated to be 34 mrad (FWHM). Since the polarization state of the crossed undulator depends on observation angle, its angular dependence was evaluated. It was found that ideal polarization control is realized only in the angle range of 2.5 mrad, which is quite smaller than that of the radiation itself.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO076  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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MOPO081 Light Proton Therapy Linac LLRF System Development LLRF, cavity, proton, interface 171
 
  • B.B. Baricevic, A. Bardorfer, R. Cerne
    I-Tech, Solkan, Slovenia
  • G. De Michele, Ye. Ivanisenko
    AVO-ADAM, Meyrin, Switzerland
 
  Proton cancer therapy is a state-of-the-art medical treatment technique based on an accelerator beam production facility. The LIGHT linear accelerator design by AVO-ADAM offers a modular compact solution for precise control of the treatment dose delivery, both position and energy wise. Proton energy can be modulated at up to 200 Hz in a range from 70 to 230 MeV by varying the gradient of the accelerating structures. The normal conducting LINAC RF system is based on a 750 MHz RFQ and 12 S band stations individually controlled. A customized LLRF system is being developed on the Libera LLRF platform for the LIGHT project. The paper is describing the required cavity field control functionality and the other subsystems such as master oscillator reference, cavity tuning, real-time control, data acquisition, control system and synchronization interfaces.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO081  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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MOPO094 RF Stability Test of RFQ Cavity with Prototype Low-level Radio Frequency in RAON rfq, LLRF, cavity, experiment 204
 
  • D.Y. Lee, B.H. Choi, C.O. Choi, H. Jang, H.C. Jung, K.T. Son
    IBS, Daejeon, Republic of Korea
 
  RAON is a heavy ion accelerator of the Institute for Basic Sciences (IBS) in Korea. The prototype Low-Level Radio Frequency (LLRF) operated at 81.25 MHz has been designed and fabricated for a prototype Radio Fre-quency Quadrupole (RFQ) cavity in RAON. Stabilities of ±1 % in amplitude and ±1 degree in phase are required for specifications of the RFQ system. The prototype LLRF controls the RF amplitude and phase in the cavity by PID feedback loop. The prototype LLRF has been tested with one RFQ cavity and stabilities have been measured. In this paper, we present the design and results of stability test.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO094  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO102 Progress of MicroTCA.4 based LLRF System of TARLA LLRF, cavity, hardware, framework 220
 
  • C. Gumus, M. Hierholzer, H. Schlarb, Ch. Schmidt
    DESY, Hamburg, Germany
  • A.A. Aksoy, A. Aydin, C. Kaya
    Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
  • O.F. Elcim
    Ankara University Institute of Accelerator Technologies, Golbasi, Turkey
 
  The Turkish Accelerator and Radiation Laboratory in Ankara (TARLA) is constructing a 40 MeV Free Electron Laser with continuous wave RF operation. DESY is responsible for delivering a turnkey LLRF system based on MicroTCA.4 standard that will be used to control four superconducting (SC) TESLA type cavities as well as the two normal conducting buncher cavities. This highly modular system is further used to control the mechanical tuning of the SC cavities by control of piezo actuators and mechanical motor tuners. With the usage of ChimeraTK framework, integration to EPICS control system is also implemented. This poster describes the system setup and integration to the existing accelerator environment with hardware and software components along with the latest updates from the facility.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO102  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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MOPO104 LLRF R&D Towards CW Operation of the European XFEL FEL, cavity, resonance, LLRF 223
 
  • A. Bellandi, V. Ayvazyan, J. Branlard, C. Gumus, S. Pfeiffer, K.P. Przygoda, R. Rybaniec, H. Schlarb, Ch. Schmidt, J.K. Sekutowicz
    DESY, Hamburg, Germany
  • W. Cichalewski
    TUL-DMCS, Łódź, Poland
 
  The ever growing request for machines with a higher average beam pulse rate and also with a relaxed (< 1 MHz) pulse separation calls for superconducting linacs that operate in Long Pulse (LP) or Continuous Wave (CW) mode. For this purpose the European X-ray Free Electron Laser (European XFEL) could be upgraded to add the ability to run in CW/LP mode. Cryo Module Test Bench (CMTB) is a facility used to perform tests on superconducting cavity cryomodules. Because of the interest in upgrading European XFEL to a CW machine, CMTB is now used to perform studies on XM-3, a 1.3 GHz European XFEL-like cryomodule with modified coupling that is able to run with very high quality factor (QL = 10E7…10E8) values. The RF power source allows running the cavities at gradients larger than 16 MV/m. Because of the QL and gradient values involved in these tests, detuning effects like mechanical resonances and microphonics became more challenging to regulate. The goal is then to determine the appropriate set of parameters for the LLRF control system to keep the error to be less than 0.01° in phase and 0.01% in amplitude.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO104  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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MOPO106 New Digital LLRF System for HIT cavity, LLRF, linac, feedback 227
 
  • E. Feldmeier, Th. Haberer, A. Peters
    HIT, Heidelberg, Germany
 
  The Heidelberg Ion Therapy Center HIT is in clinical operation since 2009. The accelerator complex consists of a linear accelerator and a synchrotron to provide carbon ions and protons for clinical use as well as helium and oxygen ions. The analog LLRF system for the linac should be replaced after more than 10 years of continuous operation. In its life-time the LLRF caused no interruption of the clinical operation with a downtime of more than 15 minutes. In order to keep the reliability in the next 10 years at least as high, a new digital LLRF system is planned. Further difficulties for the installation of a new system are due to the clinical full time usage of the accelerator and the short maintenance slots of only two days in series.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO106  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO107 Performance Evaluation of the RF Reference Phase Stabilization System on Fiber-optical Link for KEK e/e+ Injector LINAC feedback, linac, EPICS, network 230
 
  • N. Liu, B. Du
    Sokendai - Hayama, Hayama, Japan
  • D.A. Arakawa, H. Katagiri, T. Matsumoto, S. Michizono, T. Miura, F. Qiu, Y. Yano
    KEK, Ibaraki, Japan
  • T. Matsumoto, T. Miura, F. Qiu
    Sokendai, Ibaraki, Japan
 
  KEK e/e+ injector is the 600 m J-shaped LINAC which has 8 RF sectors. Stabilization of RF phase reference for long distance transmission is necessary for stable RF operation. In the present system, single-mode fiber-optical links without feedback control are used from sector 2 to 5. For the SuperKEKB, the phase stability requirement is within 0.1 deg. rms. The more stable RF phase reference is necessary to improve the phase stability. In this paper, a feedback control system for RF reference phase stabilization is tested for system performance evaluation. The temperature and humidity characteristics of the electric and optical components and phase stabilized optical fiber (PSOF) with different wavelengths will also be presented.  
poster icon Poster MOPO107 [2.026 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO107  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO116 Study on the Control Technology of Large-load Time Constant Accelerator Magnet Power Supply power-supply, collider, simulation, quadrupole 239
 
  • X. Wang, F. Long
    IHEP, Beijing, People’s Republic of China
 
  With the increasing application of power supply to industrial system, digital control system has become the mainstream of modern industrial control system. The wide application of digital control system has also led to the rapid development of digital controller. In the field of accelerator magnet power supply, the adoption of digital closed-loop control has become a trend in recent years. Due to the system’s tracking and regulation characteristics, the output current will slowly track the change of the given value in the course of the given current gradually rising. When the system reaches steady state, the disturbance of the system requires the regulator to adjust at a faster rate to correct the impact of the disturbance on the system. Today’s digital power supply control method mainly reflected in when load time constant is large, interference or load change, the power output is prone to overshoot or adjust the time is long, so the tracking and adjustment features cannot be met simultaneously. Therefore, this paper will study the power supply digital control technology for large - load time constant and the independent control method of tracking and regulating.  
poster icon Poster MOPO116 [0.307 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO116  
About • paper received ※ 21 August 2018      issue date ※ 18 January 2019  
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MOPO119 Design of a Fully Automated Test Bench for Measuring the Field Distribution in Standing Wave Cavity cavity, simulation, coupling, network 246
 
  • Y. Lu, G. Feng, T. Hu, J. Jiang, X.D. Tu, Y.Q. Xiong
    HUST, Wuhan, People’s Republic of China
 
  The resonant cavity plays a great role in the linear accelerator. An accurate measurement of the cavity field distribution is very important to design linear accelerators. A fully computer controlled bench for the electric field distribution has been developed in this context. Based on the perturbation theory, the acquisition of the resonant frequency shift is proportional to the square of E (electric field). In order to verify the reliability of the test bench, a standard cylindrical cavity has been tested in this measurement system. The simulation by HFSS (High Frequency Structure Simulator) and the practice will be both presented in this paper. And the result demonstrates that, because of its high concentricity, the automated test bench achieves high precision in measuring the distribution of electric field.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO119  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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MOPO122 European XFEL Cooling and Ventilation Systems FEL, undulator, photon, experiment 257
 
  • J.-P. Jensen
    DESY, Hamburg, Germany
 
  The European Free Electron Laser XFEL is operating since 2016. The technical systems for cooling and Ventilation CV were design, built and commissioned by the DESY work package WP34. The CV systems will be described and presented. The water cooling system consists of 3 cooling systems: 30/45 °C LCW for klystron and magnet cooling, 20/30 °C LCW for tunnel rack cooling and 8/14 °C for air conditioning and dehumidification of the air. The ventilation of the tunnels is connected to a series ventilation system from the experimental hall in direction to the injector. The series ventilation of the tunnels saves costs for air treatment with cooling, heating and dehumidification. The tunnel walls are a good heat storage that increases the air temperature stability by a factor of ten. The advantages of this concept will be discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO122  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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TUPO002 Electron Gun for 100 MeV / 100 kW Linear Accelerator of Electrons as the Driver of Nuclear Subcritical Assembly Neutron Source gun, electron, neutron, cathode 323
 
  • M. Moisieienko, O. Bezditko, A. Mytsykov, A.Y. Zelinsky
    NSC/KIPT, Kharkov, Ukraine
 
  100 MeV / 100 kW linear electron accelerator of The "neutron source" nuclear subcritical assembly uses the 120 KW triode electron gun as the primary source of electrons. The gun is designed, manufactured and tested at IHEP, Beijing, China. At present, the gun is installed, tested. The maximum impulse current of the gun equal to 2 A. Under design operation, the impulse current of the gun equal to 0.55 A.The report describes the construction of a 120 kV triode electron gun, the results of testing and test operation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO002  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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TUPO007 FRIB Fast Machine Protection System: Chopper Monitor System Design FPGA, machine-protect, high-voltage, power-supply 336
 
  • Z. Li, D. Chabot, S. Cogan, S.M. Lidia, R.C. Webber
    FRIB, East Lansing, USA
 
  Funding: Work supported by Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The Facility for Rare Isotope Beams tunes the beam power from 0 to 400KW by chopping the beam current with a beam chopper in the Low Energy Beam Transport. A chopper monitoring system is employed to verify proper chopper operation to avoid delivery of undesired high-powered beam and to inhibit beam for machine protection purposes. The system monitors the incoming beam gate time structure, the chopper switch high voltage pulses, the chopper electrode charge/discharge currents, and the status of machine protection system. It is designed to switch off the beam within tens of nanoseconds of a detected fault. Chal-lenges include a dynamic beam gate pulse structure with pulse lengths as short as 0.6 µs and high voltage power supply current pulses of ~25 ns. A high speed "integrate and hold circuit with reset", Field Program-mable Gate Array based digital control circuit and high speed ADC circuit were developed to fulfil the re-quired functions. Design approach, simulation, and test results with the beam are the focus of this paper.
 
slides icon Slides TUPO007 [1.082 MB]  
poster icon Poster TUPO007 [1.321 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO007  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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TUPO014 TRIUMF ISAC LINAC Developments and Upgrades ISAC, operation, linac, cavity 355
 
  • Z.T. Ang, T. Au, Y. Bylinskii, K. Fong, J.J. Keir, D. Lang, R.E. Laxdal, R. Leewe, B.S. Waraich, Z.Y. Yao, Q. Zheng, V. Zvyagintsev
    TRIUMF, Vancouver, Canada
 
  TRIUMF ISAC accelerator complex is in consists of ISAC-I room temperature linac and ISAC-II superconducting linac structure. ISAC-I linac has seventeen RF systems in operation for about twenty years, and ISAC-II linac has forty superconducting QWR RF cavities in operation for more than ten years. A small ISAC booster 3-gap structure at 11.78 MHz located in upstream of RFQ has been designed and installed for energy matching to RFQ. A sliding mode extremum seeking control for LLRF control was developed and implemented in operation. Six of DTL systems have been working in the control mode. Two of them had been commissioning and in operation one and half year reliably. RFQ, two more DTL system, HEBT rebuncher and DSB buncher system will be upgraded in the sliding mode control soon. Twenty ISAC-II SBC superconducting cavity RF power amplifiers were upgraded from YV-229 triode tube amplifier into solid state amplifier(SSA). The prototype and four SSAs have been commissioned in 2017 and in operation successfully. The rest of 16 SSA have been tested in RF lab and installed for operation at the mid of this year.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO014  
About • paper received ※ 04 September 2018      issue date ※ 18 January 2019  
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TUPO019 SPIRAL2 Cryogenic System Thermodynamic Behavior Prediction Through Dynamic Modeling cryomodule, cryogenics, cavity, experiment 366
 
  • A.V. Vassal, P.-E. Bernaudin, A. Ghribi
    GANIL, Caen, France
  • P.-E. Bernaudin
    CEA/DSM/IRFU, France
  • P. Bonnay, F. Bonne
    CEA/INAC, Grenoble Cedex 9, France
  • F. Millet
    CEA, Grenoble, France
 
  SPIRAL 2 (Caen, France) is a state of the art superconducting linear accelerator composed of 26 quarter wave accelerating cavities. Each cavity is plunged in a liquid helium bath at 4.4 K itself surrounded by a thermal shield at 70 K. In this paper, a dynamic model of the cryogenic systemof the LINAC is proposed. Thismodel simulates the dynamic behaviour of the 19 cryomodules and their respective valves box connected through the cryodistribution. Model accuracy is evaluated through a comparison between simulation and experimental data. Using the model we should be able to predict the behaviour of the cryogenic system for different beam operating conditions of the accelerator. The model also highlights the link between the cryogenic system and the cavity RF losses through a dynamic estimator of those RF losses in the cavity walls. The latter could be used as a rough estimator of the quality factor of a cavity.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO019  
About • paper received ※ 13 September 2018      issue date ※ 18 January 2019  
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TUPO022 Manufacturing of X-band Accelerating Structures: Metrology Analysis and Process Capability GUI, collider, linear-collider, linac 374
 
  • J. Sauza-Bedolla, S. Atieh, N. Catalán Lasheras
    CERN, Geneva, Switzerland
 
  The fabrication tolerances of RF components are essential for CLIC X-band accelerating structures to perform efficiently. On one hand, the capability of high power accelerating structures depends on the shape accuracy and the asperity of the inner surfaces, when microwaves pass through the cavity. On the other hand, surface flatness and dimensional tolerances are necessary to guarantee a correct assembly process. Hence, the discs that build up the structure require sub-micrometre specifications and, in order to meet all the needs, ultra-precision machining using single crystal diamond tools is mandatory. This paper shows the analysis of the metrology results of the fabrication of 118 discs (4 accelerating structures). Dimensional and form tolerances are studied following the production order to find drifts in the production and to predict the impact on the assembly process. Finally, process capability is evaluated.  
poster icon Poster TUPO022 [2.987 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO022  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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TUPO040 Tests of Multi-frequency Coaxial Resonators cavity, TRIUMF, niobium, rf-amplifier 420
 
  • Z.Y. Yao, J.J. Keir, P. Kolb, A. Kong, R.E. Laxdal, B. Matheson, E. Thoeng, B.S. Waraich, Q. Zheng, V. Zvyagintsev
    TRIUMF, Vancouver, Canada
 
  A significant issue in low beta resonators is medium field Q-slope (MFQS) at 4K. To study the MFQS and the field dependence of surface resistance in low beta resonators, a quarter-wave resonator (QWR) and a half-wave resonator (HWR) were designed to be tested at integer harmonic frequencies of 200MHz, and up to 1.2GHz. A series of chemistry and heat treatments are proposed to these cavities. A systemic study on the surface resistance of the coaxial resonators associating with post-processing, RF field, and frequency is in progress. The cavities were designed and fabricated. The cold test results will be discussed in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO040  
About • paper received ※ 17 September 2018      issue date ※ 18 January 2019  
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TUPO043 New Progress with HF-free Chemical Finishing for Nb SRF Cavities cavity, SRF, niobium, ECR 431
 
  • H. Tian, J. Carroll, C.E. Reece, B. Straka
    JLab, Newport News, Virginia, USA
  • T.D. Hall, M.E. Inman, R. Radhakrishnan, E.J. Taylor
    Faraday Technology, Inc., Clayton, Ohio, USA
 
  Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under contract DE-AC05-06OR23177.
Jefferson Lab has implemented a bipolar pulsed electropolishing system for final chemical processing of niobium SRF cavities. This FARADAYIC bi-polar electropolishing (BPEP) has been applied to single cells, a 7-cell CEBAF C100 cavity, and to 9-cell TESLA-style cavities.* As a mechanistic characterization of the process emerges, the critical role played by the local current density during each cathodic pulse is becoming clear. This influences system and operational parameter refinement. We present current process parameters, removal characterization, and rf performance of the processed cavities. This is the fruit of collaborative work between Jefferson Lab and Faraday Technology, Inc. directed toward the routine commercialization and industrialization of niobium cavity processing. We also present supporting data from controlled-parameter coupon studies
* E.J. Taylor, et al. "Electrochemical system and method for electropolishing superconductive radio frequency cavities" U.S. Pat. No. 9,006, 147 (& international counterparts) issued April 14, 2015.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO043  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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TUPO066 Lower Critical Field Measurement of Thin Film Superconductor solenoid, experiment, SRF, embedded 484
 
  • H. Ito
    Sokendai, Ibaraki, Japan
  • C.Z. Antoine
    CEA/IRFU, Gif-sur-Yvette, France
  • A. Four
    CEA/DRF/IRFU, Gif-sur-Yvette, France
  • H. Hayano, T. Kubo, T. Saeki
    KEK, Ibaraki, Japan
  • R. Ito, T. Nagata
    ULVAC, Inc, Chiba, Japan
  • Y. Iwashita, R. Katayama, H. Tongu
    Kyoto ICR, Uji, Kyoto, Japan
  • H. Oikawa
    Utsunomiya University, Utsunomiya, Japan
 
  Funding: The work is supported by Japan Society for the Promotion of Science Grant-in-Aid for Young Scientist (A) No.17H04839.
Superconducting thin film is the promising technology to increase the performance of SRF cavities. The lower critical field Hc1, which is one of the important physical parameters characterizing a superconducting material, will be enhanced by coating Nb with thin film superconductor such as NbN. To investigate the Hc1, we developed the Hc1 measurement system using the third harmonic response of applied AC magnetic field. The measurement system consists of helium cryostat with two of GM refrigerators, sample Cu stage, solenoid coil Cu mount, solenoid coil, temperature sensors, and liquid helium level meter. AC magnetic field is produced by a coil which is driven by function generator and power amplifier at around 1 kHz. In order to control the temperature of the sample, we installed heaters and thermal anchors which could be moved by the motor. By this temperature control the sample state can be easily transferred from Meissner state to mixed state. So that the measurement is repeated for various applied magnetic field, and the transition curve can be made. In this report, measurement result of the bulk Nb sample and NbN-SiO2 multilayer thin film sample will be discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO066  
About • paper received ※ 19 September 2018      issue date ※ 18 January 2019  
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TUPO069 Development of Vertical Electropolishing Facility for Nb 9-cell Cavity (2) cavity, cathode, niobium, experiment 494
 
  • Y.I. Ida, V. Chouhan, K.N. Nii
    MGH, Hyogo-ken, Japan
  • T. Akabori, G.M. Mitoya, K. Miyano
    HKK, Morioka, Japan
  • Y. Anetai, F. Takahashi
    WING. Co.Ltd, Iwate-ken, Japan
  • H. Hayano, S. Kato, H. Monjushiro, T. Saeki, M. Sawabe
    KEK, Ibaraki, Japan
 
  In IPAC18 (Vancouver, Canada), we reported our first step of development of niobium 9-cell cavity vertical electropolishing (VEP) facility. In this article, we will report the method, system for uniform polishing for niobium 9-cell cavities and the current situation of our 9-cell cavity VEP facility (The result of polishing uniformity, vertical test will be presented in other posters of this conference). In addition, we will show the movie of experiments of VEP-3 with Ninja cathode. This facility aims not only for test VEP but also for mass production and long-time operation.  
poster icon Poster TUPO069 [0.316 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO069  
About • paper received ※ 13 September 2018      issue date ※ 18 January 2019  
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TUPO072 First Trial of the In-situ Nitrogen Infusion at KEK cavity, vacuum, niobium, SRF 503
 
  • T. Konomi, T. Dohmae, E. Kako, S. Michizono, H. Sakai, K. Umemori
    KEK, Ibaraki, Japan
  • T. Okada
    Sokendai, Ibaraki, Japan
 
  The nitrogen infusion is the new surface treatment technique for improving the RF loss and the maximum accelerating gradient of superconducting cavity. In this process, it is important to be carried out continuously both the 800 C annealing in vacuum and 120 C nitrogen infusion without exposure to the atmosphere. The annealing serves activation process by removing the oxide layer. The in-situ nitrogen infusion system was prepared to investigate whether nitrogen infusion effect or something changes happen in the case of applying nitrogen infusion technique without removing the oxide layer. It can only introduce nitrogen into a cavity during 120 C low temperature baking and transport a cavity to the vertical test system without exposure to the atmosphere. We tried to infuse nitrogen to a single cell by keeping 120 C and 48 hours with 3 Pa nitrogen. The cavity was annealed in another furnace and applied high pressure rinsing before nitrogen infusion. The vertical test result was same Q as the normal 120 C baking without nitrogen. It suggests that oxide layer prevents infusion of nitrogen. In this poster, the in-situ nitrogen infusion system and vertical test results will be reported.  
poster icon Poster TUPO072 [4.653 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO072  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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TUPO095 Beam Loading with the First Rebuncher of Spiral2, First Measurements cavity, simulation, experiment, linac 546
 
  • M. Lechartier, R. Ferdinand, J.F. Leyge
    GANIL, Caen, France
 
  In the SPI2 project the middle energy line (LME) is equiped with a radio frequency qupole and three Rebunchers. The subject of this article is to measure and characterise the effect of the beam loading on the first Rebuncher cavity.  
poster icon Poster TUPO095 [1.146 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO095  
About • paper received ※ 20 September 2018      issue date ※ 18 January 2019  
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TUPO097 Design of C-band Electron Linear Accelerator for a Complex of Radiation Therapy electron, gun, target, radiation 550
 
  • L. Ovchinnikova, V.I. Shvedunov
    SINP MSU, Moscow, Russia
  • L. Ovchinnikova, V.I. Shvedunov
    LEA MSU, Moscow, Russia
 
  Funding: This material is based upon work supported by the Ministry of Education and Science of the Russian Federation, under Grant Agreement No. 14.582.21.0011, Grant Agreement Unique ID RFMEFI58217X0011.
The report presents the design of the linear electron accelerator for a complex of radiation therapy. The three-electrode electron gun and C-band accelerating structure are optimised to produce a therapeutic electron beam with an energy of 6 MeV and a dose rate of 10 Gy/min and a beam with an energy of 2.5 MeV to obtain a portal image. The beam size at the bremsstrahlung target in both modes does not exceed 2 mm. The total length of the accelerating system with the electron gun does not exceed 330 mm. The accelerating structure is fed by RF power from a multibeam klystron at a frequency of 5,712 MHz with a maximum pulsed power of 3.5 MW.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO097  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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TUPO130 The Design of HEPS Magnet Database and Applications database, magnet-design, operation, software 591
 
  • Y.S. Qiao, F.S. Chen, C.P. Chu
    IHEP, Beijing, People’s Republic of China
 
  HEPS (High Energy Photon Source) is a planned ultra-bright and extremely low emittance synchrotron light source which will contain about 2500 magnets. The magnet related data including design, measurements, tests, and operation are typically scattered in various storages which can be hard to access for high-level purposes. For such a large number of magnets, it is very important to have essential magnet information systematically stored in relational databases for efficient management and applications. This paper outlines the conceptual and the functional design for the HEPS magnet database and its associated applications, mainly for design of the database schema and application software architecture. This database is developed with MySQL. To provide a better view and access function of magnet related data, a web-based management platform has been developed for data uploading, querying and data managing.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO130  
About • paper received ※ 10 September 2018      issue date ※ 18 January 2019  
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TUPO132 Implementation of the Beam Loading Compensation Algorithm in the LLRF System of the European XFEL LLRF, cavity, FEL, feedback 594
 
  • Ł. Butkowski, J. Branlard, M. Omet, R. Rybaniec, H. Schlarb, Ch. Schmidt
    DESY, Hamburg, Germany
 
  In the European XFEL, a maximum number of 2700 electron bunches per RF pulse with beam currents up to 4.5mA can be accelerated. Such large beam currents can cause a significant drop of the accelerating gradients, which results in large energy changes across the macro-pulse. But, the electron bunch energies should not deviate from the nominal energy to guarantee stable and reproducible generation of photon pulses for the European XFEL users. To overcome this issue, the Low Level RF system (LLRF) compensates in real-time the beam perturbation using a Beam Loading Compensation algorithm (BLC) minimizing the transient gradient variations. The algorithm takes the charge information obtained from beam diagnostic systems e.g. Beam Position Monitors (BPM) and information from the timing system. The BLC is a part of the LLRF controller implemented in the FPGA. The article presents the implementation of the algorithm in the FPGA and shows the results achieved with the BLC in the European XFEL.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO132  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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WE1A06 Pulse-to-pulse Beam Modulation for 4 Storage Rings with 64 Pulsed Magnets power-supply, positron, electron, linac 609
 
  • Y. Enomoto, K. Furukawa, T. Kamitani, F. Miyahara, T. Natsui, M. Satoh, K. Yokoyama, M. Yoshida
    KEK, Ibaraki, Japan
  • H.S. Saotome
    Kanto Information Service (KIS), Accelerator Group, Ibaraki, Japan
  • S. Ushimoto
    Mitsubishi Electric System & Service Co., Ltd, Tsukuba, Japan
 
  The KEK injector linac has delivered electrons and positrons for particle physics and photon science experiments for more than 30 years. It is planned to inject electron and positron beams with energies from 2.5 GeV to 7 GeV pulse-by-pulse at 50 Hz into the dual ring SuperKEKB collider and two light source storage rings. As the beam quality requirement from SuperKEKB is demanding, the beam orbit and optics conditions have to be maintained precisely. To that end 64 newly designed pulsed magnets were installed. Quadrupole magnets with the inductance of 1 mH are driven by power supplies with pulses up to 330 A and 0.5 ms, which recover the energy stored in coils up to 65%. Orbit corrector magnets with the inductance of 3 mH are driven with bipolar pulsed power supplies up to 10 A. Those power supplies are controlled under the event-based synchronized controls and monitored pulse-by-pulse, and are confirmed to have the stability over weeks within 0.1%. The details of the design and the operational performance will be reported.  
slides icon Slides WE1A06 [6.694 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-WE1A06  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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THPO007 MESA - Status of the Implementation of the MicroTCA.4-based LLRF Control System cavity, LLRF, experiment, simulation 691
 
  • J.N. Bai, K. Aulenbacher, J. Diefenbach, F. Fichtner
    IKP, Mainz, Germany
  • P. Echevarria
    HZB, Berlin, Germany
  • R.G. Heine
    KPH, Mainz, Germany
 
  MESA at the Institut für Kernphysik (KPH) at Johannes Gutenberg-Universität Mainz is a multi-turn energy recovery linac (ERL), aiming to serve as user facility for particle physics experiments. The RF-accelerating systems of MESA consist of four 9-cell TESLA superconducting cavities, four normal conducting (NC) pre-accelerator cavities, two NC buncher cavities and two NC chopper cavities. They operate in continuous wave (CW) mode. In order to control the radio frequency (RF) amplitude and phase within the 12 cavities with the required accuracy and stability in the range of better than 0.01% and 0.01°, the MicroTCA.4 based digital low-level RF (LLRF) control system based on the development at DESY, Hamburg will be well adapted for the MESA cavities. In this paper, we describe the theoretical modelling of superconducting cavity and PID controller in SIMULINK which is useful to find the suitable control parameter for the PID controller and to predict the system performance. The progress to date of the implementation and tests of the LLRF system at MESA will also be presented.  
poster icon Poster THPO007 [1.274 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO007  
About • paper received ※ 11 September 2018      issue date ※ 18 January 2019  
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THPO011 First Energy Recovery Operation at the S-DALINAC: RF Control Stability Measurements operation, cavity, linac, beam-loading 706
 
  • M. Steinhorst, M. Arnold, N. Pietralla
    TU Darmstadt, Darmstadt, Germany
  • C. Burandt
    HIM, Mainz, Germany
 
  Funding: *Supported by the DFG through GRK 2128.
One of the main research instruments at the institute for nuclear physics at the TU Darmstadt is the recirculating superconducting linear accelerator S‑DALINAC. Many improvements were implemented since the first recirculated beam in 1991. One of the major enhancement is the upgrade from a twice to a thrice recirculating scheme in 2015/2016. With this upgrade the operation mode can be changed between a conventional accelerating operation and energy recovery linac (ERL) mode by an 180° rf phaseshift of the beam done via a path length variation of the arcs in the second recirculation. ERL operation was not possible when the rf control system for the superconducting structures was set up in 2010. Therefore the current rf control system is not optimized for this kind of operation and so it had to be tested during ERL operation in order to also demonstrate its capability of this operation mode. In August 2017 a first once recirculating ERL operation was achieved. During this operation measurements regarding the rf control stability and the demand of rf power were done. This contribution is discussing this measurements and possible improvements for future energy recovery beam times.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO011  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO018 Building a 12GHz Traveling Wave Accelerating Structure Brazed Through Irises linac, cavity, linear-collider, collider 721
 
  • V.A. Dolgashev, G.B. Bowden, M. Dal Forno, A.A. Haase
    SLAC, Menlo Park, California, USA
  • A. Grudiev
    CERN, Geneva, Switzerland
  • H. Zha
    TUB, Beijing, People’s Republic of China
 
  Accelerating structures are usually manufactured by precision turning of individual cells combined with precision milling for complex parts such as rf power couplers. These multiple parts are staked and brazed into a complete structure. We consider an alternative approach: precision milling of multiple cells and couplers into metal blocks that comprise halves or quadrants of the complete structure. We successfully produced a 12~GHz Compact Linear Collider (CLIC) main linac accelerating structure prototype using this method. A previous prototype was designed as an open structure with a gap between cell irises. Here we describe a different approach, an accelerating structure which is brazed through irises. It is based on a multi-cell traveling wave structure designed at CERN for PSI, so called "T24 PSI 12 GHz". This brazed-through irises structure was built at SLAC for high power tests at CERN. Here we describe the details of this process.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO018  
About • paper received ※ 19 September 2018      issue date ※ 18 January 2019  
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THPO054 Recent Progress of a CW 4-rod RFQ for the SSC-LINAC rfq, linac, MMI, emittance 814
 
  • Z.S. Li, Y. Cong, H. Du, Y. He, L. Jing, Q.Y. Kong, X.N. Li, J. Meng, G.D. Shen, K.D. Wang, Z.J. Wang, W. Wei, J.X. Wu, J.W. Xia, H.M. Xie, W.J. Xie, Z. Xu, J.C. Yang, Y.Q. Yang, X. Yin, Y.J. Yuan, Y. Zhang
    IMP/CAS, Lanzhou, People’s Republic of China
  • Y.R. Lu
    PKU, Beijing, People’s Republic of China
 
  The SSC-LINAC is under design and construction as a linear injector for the Separated-Sector Cyclotron (SSC) of the Heavy Ion Research Facility at Lanzhou (HIRFL). The continuous-wave (CW) 4-rod radio-frequency quad-rupole (RFQ) of the SSC-LINAC has important progress in past years. In the autumn of 2016, the cavity has been operated with 35 kW on CW mode in automatic RF con-trolled mode during RF power commissioning, which is needed to accelerate 238U34+ beams. The beam transmis-sion efficiency, transverse emittance and energy spread has been obtained in beam commissioning. In this paper, the results of experiments will be presented and discussed in detail.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO054  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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THPO067 Control System and Experiment for RAON HWR Cryomodules cryomodule, cavity, PLC, cryogenics 845
 
  • H. Kim, J.W. Choi, C.O. Choi, H. Jang, Y.W. Jo, H.C. Jung, Y. Jung, J.W. Kim, M.S. Kim, Y. Kim, D.Y. Lee, M. Lee, S. Lee, K.T. Seol, K.T. Son
    IBS, Daejeon, Republic of Korea
 
  A prototype of half-wave resonator (HWR) cryomodules is fabricated and tested. Cables and tray are installed for horizontal test. The design and the piping and instrumentation diagram (P&ID) of the HWR cryomodule are presented. The HWR cryomodule is tested with developed programmable logic controller (PLC) and experimental physics and industrial control system (EPICS) control systems. The heat loads of the HWR cryomodule for static and dynamic are measured.  
poster icon Poster THPO067 [0.631 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO067  
About • paper received ※ 10 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 cavity, FEL, power-supply, rf-amplifier 889
 
  • 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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THPO095 Present Status of Capacitor-charging Power Supplies for Klystron Modulators in SuperKEKB Injector Linac linac, klystron, status, power-supply 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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THPO097 Recent Results for Study of Ceramic and Copper Plating for Power Couplers electron, survey, target, FEL 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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THPO103 Application of Solid State Amplifiers in ADS Project at IHEP cavity, power-supply, MMI, ISOL 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 coupling, power-supply, insertion, radiation 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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FR1A06 Pulse-by-Pulse Beam Parameter Switching of High-Quality Beams for Multi-Beamline Operation at SACLA FEL, electron, laser, optics 988
 
  • H. Maesaka, T. Fukui, T. Hara, Y. Otake
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
  • T. Hasegawa, O. Morimoto, Y. Tajiri, S. Tanaka, M. Yoshioka
    SES, Hyogo-pref., Japan
  • N. Hosoda, S. Matsubara, T. Ohshima
    JASRI/SPring-8, Hyogo-ken, Japan
  • C. Kondo, M. Yamaga
    JASRI, Hyogo, Japan
 
  The main linac of the X-ray free electron laser (XFEL), SACLA, provides electron beams to two XFEL beamlines and a beam transport line to the SPring-8 storage ring. In order to utilize these beamlines at the same time, a kicker magnet was installed into the switch yard and electron beams with a 60 Hz repetition rate can be distributed to these beamlines pulse-by-pulse. Since a beam energy and an optimum bunch length are usually different for each beamline, the operation condition of each acceleration unit, such as the rf phase, the trigger permission, etc., has to be changed pulse-by-pulse. Even in that case, the electron beam quality, such as 1 mm mrad normalized emittance, 10 fs bunch length, 10 kA peak current, etc., must not be deteriorated. At first, we developed a parameter control software that was able to manage two XFEL beamlines with an equal repetition rate. Different energy beams with sufficient quality for lasing were successfully distributed to the two XFEL beamlines and the XFEL performances of both beamlines were optimized simultaneously. The development status of a new parameter switching system with an arbitrary sequence of the destinations will also be reported.  
slides icon Slides FR1A06 [6.179 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-FR1A06  
About • paper received ※ 16 September 2018      issue date ※ 18 January 2019  
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