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LINAC08 - List of Authors (Yamaguchi, S.)
A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z
Operating Experience of te J-PARC Linac
K. Hasegawa, H. Asano, T. Ito, T. Kobayashi, Y. Kondo, H. Oguri, A. Ueno
S. Anami, Z. Fang, Y. Fukui, K. Ikegami, M. Kawamura, F. Naito, K. Nanmo, H. Tanaka, S. Yamaguchi
E. Chishiro, T. Hori, H. Suzuki, M. Yamazaki
Y. Namekawa, K. Ohkoshi
J-PARC, KEK & JAEA, Ibaraki-ken
Te J-PARC (Japan Proton Accelerator Research Complex) linac consists of an RFQ, a Drift Tube Linac and a Separated-type Drift Tube Linac. Te beam commissioning of te linac started in November 2006 and 181 MeV acceleration was successfully achieved in January 2007. Te linac has delivered beams to te 3 GeV Rapid Cycling Synchrotron for its commissioning, and then, te subsequent 50 GeV Main Ring Synchrotron and te neutron target commissioning. Te linac uses 20 units of 324 MHz klystrons. As of May, 2008, te average number of filament hours exceeds 5,000 without serious troubles. Te operating experience of te linac will be described in this paper.
LLRF Control System of te J-PARC LINAC
Z. Fang, S. Anami, S. Michizono, S. Yamaguchi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
At te J-PARC 181 MeV proton linac, te rf sources consist of 4 solid-state amplifiers and 20 klystrons with operation frequency of 324 MHz. Te rf fields of each rf source are controlled by a digital feedback system installed in a compact PCI (cPCI). A very good stability of te accelerating fields has been successfully achieved about ±0.2% in amplitude and ±0.2 degree in phase, much better than te requirements of ±1% in amplitude and ±1 degree in phase. Besides, te tuning of each accelerator cavity including 3 DTL and 15 SDTL is also controlled by this LLRF system through a cavity tuner. We pre-defined te cavity resonance states with te tuner adjusted to obtain a flat phase during te cavity field decay. Te cavity auto-tuning is well controlled to keep te phase of rf fields within ±1 degree. Furthermore, from te amplitude waveform during te cavity field decay, te Q-value of each cavity is calculated in real-time and displayed in te PLC TP of te LLRF control system.
Pulse-by-Pulse Switching of Beam Loading Compensation in J-PARC Linac RF Control
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
S. Anami, Z. Fang, S. Michizono, S. Yamaguchi
E. Chishiro, H. Suzuki
For te J-PARC linac low level rf system, in order to compensate beam-loading change by pulses in te operation of 25 Hz repetition, a function that switches te feed-forward control parameters in every pulse were installed into te digital accelerating-field control system. Te linac provides a 50 mA peak current proton beam to a 3 GeV rapid-cycling synchrotron (RCS). Then te RCS distributes te 3-GeV beam into a following 50 GeV synchrotron (main ring, MR) and te Materials and Life Science Facility (MLF), which is one of te experimental facilities in te J-PARC. Te 500-us long macro pulses from te ion source of te linac should be chopped into medium pulses for injection into te RCS. Te duty (width or repetition) of te medium pulse depends on which facility te RCS provides te beam to te MR or MLF. Therefore te beam loading compensation needs to be corrected for te change of te medium pulse duty in te 25 Hz operation.