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MOPO116 Study on the Control Technology of Large-load Time Constant Accelerator Magnet Power Supply 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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MOPO118 Optimized Design for a Compact Linac with Collinear Absorbing Loads at the Hust FEL-THz 242
SPWR029   use link to see paper's listing under its alternate paper code  
 
  • J. Jiang, G. Feng, T. Hu, Y. Lu, X.D. Tu, Y.Q. Xiong
    HUST, Wuhan, People’s Republic of China
  • Y.J. Pei
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  To meet the requirement of miniaturization for high power THz radiation in the field of commercial and civil use, RF Linacs have been applied widely as beam injectors, and the Linac with collinear absorbing loads reveals the potential to achieve a tradeoff between performance and compactness. Under overall consideration of systematic conflicts, optimization choices for such Linacs involving power absorbing ability, accelerating efficiency, as well as beamline length were described in this context. Meanwhile, cold testing has been conducted to verify design parameters for the collinear absorbing loads. Furthermore, elaborated calculation of thermal power loss and integrated helical water channel cooling has been performed for the 14MeV Linac with collinear absorbing loads installed on the HUST FEL-THz, and online experiments demonstrated that both the accelerating efficiency and the water cooling performance fulfilled operation demands.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO118  
About • paper received ※ 11 September 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 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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MOPO120 Improvement of the Linear Part in the Tuner System of ADS 25 MeV Linac 250
 
  • L. Zhang, Z. Gao, L.B. Liu, F.F. Wang, B. Zhang
    IMP/CAS, Lanzhou, People’s Republic of China
 
  Tuner system is the indispensable part of ADS high current proton superconducting linac. It influences the working frequency of superconducting cavity of particle accelerator. To completely understand the working situa-tion of the tuner system and analyses the problems existing in it, experiments of linear part were fully conducted.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO120  
About • paper received ※ 09 September 2018      issue date ※ 18 January 2019  
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MOPO121 Large-Scale Optical Synchronization System of the European XFEL 253
 
  • J.M. Müller, M. Felber, T. Kozak, T. Lamb, H. Schlarb, S. Schulz, C. Sydlo, M. Titberidze, F. Zummack
    DESY, Hamburg, Germany
 
  At the European XFEL, a facility-wide optical synchronization system providing a femtosecond-stable timing reference at more than 40 end-stations had been developed and installed. The system is based on an ultra-stable, low-noise laser oscillator, whose signals are distributed via actively length-stabilized optical fibers to the different locations across the accelerator and experimental areas. There, it is used to locally re-synchronize radio frequency signals, to precisely measure the arrival time of the electron beam for fast beam-based feedbacks, and to phase-lock optical laser systems for electron bunch generation, beam diagnostics and user pump-probe experiments with femtosecond temporal resolution. In this paper, we present the system’s architecture and discuss design choices to realize an extensible, large-scale synchronization infrastructure for accelerators that meets reliability, maintainability as well as the performance requirements. Furthermore, the latest performance result of an all-optically synchronized laser oscillator is shown.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO121  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO122 European XFEL Cooling and Ventilation Systems 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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MOPO124 Details of the Manufacturing Processes of the ESS-DTL Components 260
 
  • P. Mereu, F. Borotto Dalla Vecchia, C. Mingioni, M. Nenni, R. Panero
    INFN-Torino, Torino, Italy
  • A. Battistello, P. Bottin, D. Conventi, L. Ferrari, F. Grespan, A. Pisent
    INFN/LNL, Legnaro (PD), Italy
  • A.G. Colombo
    INFN- Sez. di Padova, Padova, Italy
 
  The Drift Tube Linac (DTL) of the European Spallation Source (ESS) is designed to operate at 352.2MHz with a duty cycle of 4% (3 ms pulse length, 14 Hz repetition period) and will accelerate a proton beam of 62.5mA pulse peak current from 3.62 to 90 MeV. This paper presents the details of the manufacturing processes with quality control reports of the components of the DTL.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO124  
About • paper received ※ 12 September 2018      issue date ※ 18 January 2019  
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MOPO125 Steering Magnets with Permanent Magnets 264
 
  • Y. Iwashita, M. Abe, T. Yako
    Kyoto ICR, Uji, Kyoto, Japan
  • Y. Fuwa
    Kyoto University, Research Reactor Institute, Osaka, Japan
  • N. Terunuma
    KEK, Ibaraki, Japan
 
  Funding: This work was supported by the Collaborative Research Program of Institute for Chemical Research, Kyoto University (grant #2018-10)
Dipole magnet using permanent magnet technology is under investigation for correction magnets in beamline. It can reduce cost of electricity of coil excitation and cooling water pump, thick electric cabling and water piping, power supply, and their maintenance cost. The structure and the field adjustment scheme whith bipolar variable range will be discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO125  
About • paper received ※ 20 September 2018      issue date ※ 18 January 2019  
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MOPO127 Recent Results from MICE on Multiple Coulomb Scattering and Energy Loss 267
 
  • J.Y. Tang
    IHEP, Beijing, People’s Republic of China
  • J.C. Nugent
    University of Glasgow, Glasgow, United Kingdom
 
  Funding: STFC, DOE, NSF, INFN, CHIPP and more
Multiple Coulomb scattering and energy loss are well known phenomena experienced by charged particles as they traverse a material. However, from recent measurements by the MuScat collaboration, available simulation codes (GEANT4, for example) are known to overestimate the scattering of muons in low Z materials. This is of particular interest to the Muon Ionization Cooling Experiment (MICE) collaboration which has the goal of measuring the reduction of the emittance of a muon beam induced by energy loss in low Z absorbers. MICE took data without magnetic field suitable for multiple scattering measurements in the fall of 2015 with the absorber vessel filled with xenon and in the spring of 2016 using a lithium hydride absorber. In the fall of 2016 MICE took data with magnetic fields on and measured the energy loss of muons in a lithium hydride absorber. These data are all compared with the Bethe-Bloch formula and with the predictions of various models, including the default GEANT4 model.
Submitted by the MICE speakers Bureau. If accepted a member of the collaboration will be selected for the mission
 
poster icon Poster MOPO127 [0.842 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO127  
About • paper received ※ 19 September 2018      issue date ※ 18 January 2019  
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MOPO129 Recent Results from the Study of Emittance Evolution at MICE 270
 
  • W.B. Liu
    IHEP, Beijing, People’s Republic of China
  • V. Blackmore, C. Hunt
    Imperial College of Science and Technology, Department of Physics, London, United Kingdom
 
  Funding: STFC, DOE, NSF, INFN, CHIPP and more
The Muon Ionization Cooling Experiment (MICE) has measured the evolution of emittance due to ionization energy loss. Muons were focused onto an absorber using a large aperture solenoid. Lithium-hydride and liquid hy- drogen-absorbers have been studied. Diagnostic devices were placed upstream and downstream of the focus, ena- bling the phase-space coordinates of individual muons to be reconstructed. By observing the properties of ensem- bles of muons, the change in beam emittance was meas- ured. Data taken during 2016 and 2017 are currently un- der study to evaluate the change in emittance due to the absorber for muon beams with various initial emittance, momenta, and settings of the magnetic lattice. The current status and the most recent results of these analyses will be presented.
Submitted by the MICE speakers Bureau. If accepted a member of the collaboration will be selected for the mission
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO129  
About • paper received ※ 30 September 2018      issue date ※ 18 January 2019  
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