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Ueno, Akira
Review of Scientific Instruments, 91(3), p.033312_1 - 033312_9, 2020/03
Times Cited Count:4 Percentile:28.61(Instruments & Instrumentation)In July 2019, a 3 GeV 920 kW beam was accelerated for 10.5 hours in the J-PARC. During the operation, the H ion source and LINAC was operated with the beam duty factor (BDF) of 1.25% (0.5 ms25 Hz) and the ejected beam intensities of 58 and 50 mA, respectively. Separately, they were stably operated with the BDF of 1.5% (0.6 ms25 Hz) and the ejected beam intensities of 72 and 60 mA, respectively. Based upon the 100-mA and BDF 5% (1 ms50 Hz) H ion source operation on a test-stand, the possibility of the 100-mA high energy and high duty factor LINACs with a radio frequency quadrupole LINAC with an injection energy higher than 64 keV is presented. The unexpectedly effective space-charge neutralization effects in the low energy beam transport are also presented. Furthermore, the transverse emittance improvements by about 8% with the shortest beam extractor are presented.
Chimura, Motoki*; Harada, Hiroyuki; Moriya, Katsuhiro; Okabe, Kota; Kinsho, Michikazu
Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.728 - 732, 2019/07
The increase of space charge effect in high intensity beam causes the increase of the beam-loss. Beam loss limits beam intensity for accelerator equipment activation. Therefore, it is important to suppress the emittance growth due to the space charge effect. I focused on the low energy region in the linac where the space charge effect becomes remarkable. In order to identify the origin of the emittance growth due to the effect, a simulation was performed with a 3-D particle-in-cell simulation code, and evaluated the influence of the effects in the J-PARC medium energy beam transport line (MEBT1) entrance to DTL exit. As a result, it was confirmed that distortion of phase space distribution occurred due to nonlinear space charge force and that leading to emittance growth. I proposed to suppress the emittance growth by using an octupole magnet that gives nonlinear force to the beam. We report the new method and simulation results.
Ouchi, Nobuo; Akaoka, Nobuo*; Asano, Hiroyuki*; Chishiro, Etsuji; Namekawa, Yuya*; Suzuki, Hiroyuki*; Ueno, Tomoaki*; Noguchi, Shuichi*; Kako, Eiji*; Ouchi, Norihito*; et al.
Proceedings of 4th International Workshop on the Utilisation and Reliability of High Power Proton Accelerators, p.175 - 183, 2005/11
no abstracts in English
Chishiro, Etsuji; Hori, Toshihiko*; Kobayashi, Tetsuya; Suzuki, Hiroyuki*; Suganuma, Kazuaki; Yamazaki, Masayoshi*; Anami, Shozo*; Fang, Z.*; Fukuda, Shigeki*; Fukui, Yuji*; et al.
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan, p.236 - 238, 2005/07
no abstracts in English
Kobayashi, Tetsuya; Chishiro, Etsuji; Suzuki, Hiroyuki*; Anami, Shozo*; Yamaguchi, Seiya*; Michizono, Shinichiro*; Kawamura, Masato*; Fukui, Yuji*; Fang, Z.*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan, p.320 - 322, 2005/07
Total System of 324MHz-Low Level RF Control for J-PARC Linac was produced and its performance study was done. In this system, in order to stabilize the Klystron output and to compensate the linearity of that, an analog feedback control system is adopted. The response function including phase characteristic (vector locus) of this feedback system was obtained by means of measurement. From this result the prospect for the transient analysis is discussed.
Morishita, Takatoshi; Ao, Hiroyuki; Ito, Takashi; Ueno, Akira; Hasegawa, Kazuo; Ikegami, Masanori*; Kubota, Chikashi*; Takasaki, Eiichi*; Tanaka, Hirokazu*; Naito, Fujio*; et al.
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.671 - 673, 2004/08
A precise alignment of accelerator components is essential for the J-PARC linear accelerator. The wire position sensor is applied to measure the accelerator component positioning and the ground motion of the building is measured by the hydrostatic leveling sensors. In this paper, the scheme of the alignment system is presented.
Hiroki, Fumio; Yoshikawa, Hiroshi; Takeuchi, Yasunori*; Kudo, Kikuo*
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.159 - 161, 2004/08
The main purpose of Personnel Protection System (PPS) is to protect people from radiation exposure. From the viewpoint of it, important features of the Japan Proton Accelerator Research Complex (J-PARC) are (1) the beam power as high as 1MW, and (2) a lot of beam-line entrances apart from the main control room. The first feature requires the beam interlock function of PPS to be more reliable than ever. The second one is dealt with the access control function of PPS, with which the remote access control from the central control room is enabled. In this paper, we report the beam interlock and access control functions of the PPS.
Kako, Eiji*; Noguchi, Shuichi*; Shishido, Toshio*; Asano, Hiroyuki*; Chishiro, Etsuji; Suzuki, Hiroyuki*; Hori, Toshihiko*; Yamazaki, Masayoshi*
Proceedings of 28th Linear Accelerator Meeting in Japan, p.324 - 326, 2004/06
no abstracts in English
Sakaki, Hironao; Nakamura, Naoki*; Takahashi, Hiroki; Yoshikawa, Hiroshi
JAERI-Tech 2004-022, 28 Pages, 2004/03
In High Intensity Proton Accelerator Project (J-PARC), the peak current 50mA(max.) proton beam is accelerated to 50GeV. Therefore, when the magnet trouble etc. occurs, and the beam collides toward the accelerating structure, the thermal shock destruction is caused on the surface of the material of the structure. This report shows the design policy of "Prototype-unit for the machine protection system" that is necessary to evade the thermal shock destruction.
Yamazaki, Yoshishige
Proceedings of 22nd International Linear Accelerator Conference (LINAC 2004), p.554 - 558, 2004/00
no abstracts in English
Tezuka, Katsuhiko*; Miyake, Setsuo*; Sakamoto, Mitsunori*; Chishiro, Etsuji; Fukuda, Shigeki*; Kawamura, Masato*; Anami, Shozo*
Proceedings of 28th Linear Accelerator Meeting in Japan, p.372 - 374, 2003/07
no abstracts in English
Kawamura, Masato*; Anami, Shozo*; Fukui, Yuji*; Kubota, Chikashi*; Ono, Masaaki*; Chishiro, Etsuji; Yumino, Yuichi*; Kubo, Hiroshi*
Proceedings of 28th Linear Accelerator Meeting in Japan, p.369 - 371, 2003/07
no abstracts in English
Saito, Shigeru; Ouchi, Nobuo; Fukaya, Kiyoshi*; Ishiyama, Shintaro; Tsuchiya, Yoshinori; Nakajima, Hideo
JAERI-Tech 2003-027, 63 Pages, 2003/03
Around the super conducting (SC) coils of SC linear accelerator or fusion reactor, several kind of dissimilar materials bond will be needed. In recent years, pure titanium has been proposed as jacket material for SC coil of fusion reactor. Cu-alloys will be used for connection of SC coils. Cryogenic stainless steels have been development for structural material. Therefore, it is necessary to develop new bonding techniques and we started the bonding technology development by hot isostatic press (HIP) method to bond Cu-alloys with titanium and cryogenic stainless steels. In this experiments, optimization of HIP bonding condition and evaluation of bonding strength by metallurgical observation, tensile and bending tests were performed.
Yamazaki, Yoshishige; Hayashizaki, Noriyosu*; Paramonov, V.*
Proceedings of 21st International Linac Conference, p.752 - 754, 2003/00
The power-handling capability is the critical issue for a high intensity proton linac of normal-conducting coupled-cavity type. In the JAERI/KEK Joint Project, a coupled-cavity linac with the Annular Coupled Structure (ACS) has been developed in order to operate with 3 % duty factor. The ACS accelerating module consists of two ACS tanks and one bridge coupler. The cooling water circuits in the ACS cells ensure the effective and uniform cooling, stabilizing the deviation of cell frequencies. Some of excited cells in the bridge coupler are equipped with fast movable tuners to tune the cavity to the operating frequency. The results of thermal and structural analysis are presented, together with the RF parameter analysis, for different linac regimes. For the adopted ACS module design, the results of the analyses suggest that the operation with the heat loading of up to 90 kW/m is possible, which is corresponding to the 15 % duty factor operation.
Joshi, S. C.*; Paramonov, V.*; Skassyrskaya, A.*; Hayashizaki, Noriyosu*; Ikegami, Masanori*; Yamazaki, Yoshishige
Proceedings of 21st International Linac Conference, p.216 - 218, 2003/00
The normal conducting coupled-cavity linac with the Annular Coupled Structure (ACS) is adopted for 190-400 MeV part of high intensity proton linac for the JAERI/KEK Joint Project. The operating frequency is 972 MHz and the 23 modules will be constructed. The basic configuration is based on that investigated for L-band (1296 MHz) in the previous Japan Hadron Project research. However, the structure design is revised and optimized in order to meet requirements of reliability, operation efficiency and cost reduction for the newly proposed Joint Project. As the results of development, the transverse dimensions of the ACS tank are reduced sufficiently with the improvement in RF characteristics. The structure segmentation and essential points of the design are described.
Hayashizaki, Noriyosu*; Ao, Hiroyuki; Hasegawa, Kazuo; Yamazaki, Yoshishige; Ikegami, Masanori*; Kato, Takao*; Paramonov, V.*
Proceedings of 21st International Linac Conference, p.234 - 236, 2003/00
The normal conducting coupled-cavity linac with the Annular Coupled Structure (ACS) is adopted for 190-400 MeV part of high intensity proton linac for the JAERI/KEK Joint Project. The operating frequency is 972 MHz and the 23 modules will be constructed. The basic configuration is based on that investigated for L-band (1296 MHz) in the previous Japan Hadron Project research. However, the structure design is revised and optimized in order to meet requirements of reliability, operation efficiency and cost reduction for the newly proposed Joint Project. As the results of development, the transverse dimensions of the ACS tank are reduced sufficiently with the improvement in RF characteristics. The structure segmentation and essential points of the design are described.
*; Miyamoto, Shuji*; *; *; *; Hasegawa, Makoto; Yamazaki, Yoshio
JNC TY9400 2000-008, 20 Pages, 2000/03
no abstracts in English
Kinsho, Michikazu; Noda, Fumiaki*
JAERI-Tech 99-011, 46 Pages, 1999/02
no abstracts in English
Kinsho, Michikazu; Noda, Fumiaki*; Kusano, Joichi; Mizumoto, Motoharu
Proc. of 1st Asian Particle Accelerator Conf. (APAC98), p.411 - 413, 1998/11
no abstracts in English
Wang, Y.
PNC TN9410 98-017, 21 Pages, 1998/02
"Injector Test (1) of PNC High Power Electron Linac" was mentioned in last year report. 100mA beam with pulse length 20s repetition rate 1Hz and 50mA beam with pulse 1ms 0.5 Hz had been accelerated to 3.0 Mev successfully. The chopper and prebuncher system had not been used in that test. Now this report put emphases on the chopper and prebuncher systems tests. A good energy spectrum had been achieved using the chopper and prebuncher systems. And 100mA beam current with pulse length 3ms and repetition rate 0.1Hz was accelerated to 3.0 MeV.