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Ono, Ayato; Takayanagi, Tomohiro; Fuwa, Yasuhiro; Shinozaki, Shinichi; Ueno, Tomoaki*; Horino, Koki*; Sugita, Moe; Yamamoto, Kazami; Kinsho, Michikazu; Ikoma, Naoya*; et al.
Proceedings of 20th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.871 - 876, 2023/11
In J-PARC, an ignitron is used for the crowbar device of the klystron power supply to excite the RF acceleration voltage in a Linac cavity. Mercury, that is used in the ignitron, would be prohibition of use in the future due to environmental protection. Therefore, we designed a semiconductor crowbar switch for short-circuit protection of klystron using a MOS gate thyristor. We have manufactured an oval-type board module that realizes an operating output of 3kV, 40kA, and 50us per board. Because a high voltage of 120 kV is applied on each board, we adopted a self-power supply method to supply a electricity for the control system. This method can create the electricity from a high-voltage DCDC converter. We confirmed the operating performance on a 1/2 scale (60 kV, 40 kA) of the voltage in the existing ignitron system (120 kV, 40 kA). We also studied a test circuit in a higher voltage range of more than 90 kV. Our latest result is well promising for an alternative system of ignitron.
Ono, Ayato; Takayanagi, Tomohiro; Fuwa, Yasuhiro; Shinozaki, Shinichi; Ueno, Tomoaki*; Horino, Koki*; Sugita, Moe; Yamamoto, Kazami; Kinsho, Michikazu; Ikoma, Naoya*; et al.
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.395 - 399, 2023/01
At J-PARC, an ignitron is used for the crowbar device of the klystron power supply for high-frequency acceleration of a linear accelerator. Ignitron uses mercury, which is of limited use worldwide, and is expected to be discontinued in the future. Therefore, we designed a semiconductor crowbar switch for short-circuit protection of klystron using a MOS gate thyristor. We have manufactured an oval-type board module that realizes an operating output of 3 kV, 40 kA, and 50 
s per board. For the control power supply to each board module assuming a high voltage of 120 kV, we adopted a self-power supply method that creates a control power supply with a high-voltage DCDC converter from the voltage shared and charged by each board module. It was possible to confirm the operating performance on a 1/2 scale (60 kV, 40 kA) against the voltage of the existing equipment (120 kV, 40 kA) by connecting twenty oval board modules in series. The output test result will be reported.
Takayanagi, Tomohiro; Ono, Ayato; Fuwa, Yasuhiro; Shinozaki, Shinichi; Horino, Koki*; Ueno, Tomoaki*; Sugita, Moe; Yamamoto, Kazami; Oguri, Hidetomo; Kinsho, Michikazu; et al.
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.242 - 246, 2023/01
At J-PARC, semiconductor short pulse power supplies to replace kicker power supplies and semiconductor long pulse power supplies to replace klystron power supply systems are under construction. We have fabricated a 40kV/2kA/1.2s unit power supply that employs a linear transformer drivers (LTD) system for kickers. Currently, we are working on a high voltage insulating cylinder insulator that suppresses corona discharges using only the insulator structure, without using insulating oil. In addition, the MARX system was adopted for klystron power supply system. A main circuit unit for 8kV/60A/830s rectangular pulse output and an 800V/60A correction circuit unit that improves the flat top droop from 10% to 1% were manufactured. Furthermore, a 2.2kV/2.4kW high voltage SiC inverter charger has been fabricated for this MARX power supply. The presentation will report the evaluation results of each test and prospects for semiconductor pulse power supplies.
Ono, Ayato; Takayanagi, Tomohiro; Ueno, Tomoaki*; Horino, Koki*; Yamamoto, Kazami; Kinsho, Michikazu
Proceedings of 18th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.831 - 834, 2021/10
The Ignitron is used in the clover device of the klystron power supply for RF acceleration in the J-PARC LINAC. However, this ignitron uses mercury, the use of which is restricted worldwide, and its production is expected to be discontinued in the future. Therefore, we designed a semiconductor clover switch for short-circuit protection of klystron using a MOS gate thyristor. We have manufactured an oval-type board module that realizes an operating output of 3 kV, 40 kA, and 50 s per board. For the control power supply to each board module assuming a high voltage of 120 kV, we adopted a self-power supply method that creates a control power supply with a high-voltage DCDC converter from the voltage shared and charged by each board module. It was possible to confirm the operating performance on a 1/4 scale (30 kV, 40 kA) against the voltage of the existing equipment (120 kV, 40 kA) by connecting ten oval board modules in series. The output test result will be reported.
Fuwa, Yasuhiro; Ono, Ayato; Takayanagi, Tomohiro; Shinozaki, Shinichi; Mizobata, Satoshi*; Fang, Z.*
Proceedings of 17th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.780 - 782, 2020/09
In the J-PARC linac, High Voltage DC power supplies (HVDC) to drive klystrons. These HVDCs are modulating-anode power supplies with a rated voltage of 110 kV and are operated by connecting up to four klystrons to a single HVDC. Since multiple klystrons are driven by a single HVDC, a voltage droop in the capacitor bank of the HVDC occurs in the beam pulse. This effect causes a decrease in the output power of the klystron. Half of the existing HVDC in J-PARC were installed at the J-PARC construction, and the other half were installed at the LINAC 400 MeV upgrade, and the capacitors show signs of age-related degradation. In the near future, the capacitors will be necessary to be replaced partially or completely. On the replacement of the capacitors, it will be necessary to re-evaluate the operating behavior of the HVDC when the capacitor bank configuration is changed. In this presentation, we evaluated the effect of the voltage droop on the klystron with the present configuration and the effect of changing the capacitor bank configuration with numerical and experimental results, and we discussed the countermeasure for the stable beam operation.
Ono, Ayato; Takayanagi, Tomohiro; Ueno, Tomoaki*; Horino, Koki*; Yamamoto, Kazami; Kinsho, Michikazu
Proceedings of 17th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.590 - 593, 2020/09
At J-PARC, an ignitron is used for the clover device of the klystron power supply for high-frequency acceleration of a linear accelerator. Ignitron uses mercury, which is of limited use worldwide, and is expected to be discontinued in the future. Therefore, a semiconductor switch for ignitron substitution using a MOS gate thyristor is designed. In order to be used as a crowbar device, a switch capable of resisting an operating output of 120 kV, 40 kA, 50 us is required. We have realized an oval type substrate module that achieves an operating output of 3 kV, 40 kA, 50 us per substrate. It was possible to confirm the operating performance on a 1/10 scale (12 kV, 40 kA) against the voltage of the existing equipment (120 kV, 40 kA) by connecting four oval board modules in series. The output test result will be reported.
Fuwa, Yasuhiro; Shinozaki, Shinichi; Chishiro, Etsuji; Hirane, Tatsuya; Fang, Z.*; Fukui, Yuji*; Futatsukawa, Kenta*; Mizobata, Satoshi*; Iwama, Yuhei*; Sato, Yoshikatsu*; et al.
Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.611 - 613, 2019/10
In the J-PARC linac, a proton accelerator is operated using 45 units of 324 MHz and 972 MHz klystrons. In the future stabilization and advancement of the accelerator, it is important to acquire the klystron output characteristics near the maximum output accurately. In order to understand this characteristics, measurement of the characteristics of the replaced klystron for some reason such as discharge, as well as the new klystron. However, such measurements have not been performed because of the risk of damage including peripheral equipment due to discharge and the temporal interference with the operation of the accelerator. Therefore, we set up a klystron test stand in the linac building and measured the high-voltage characteristics and input/output characteristics of the klystron under various operating parameters. By using this measurement result, the characteristics of klystron can be obtained before installation, and it becomes possible to determine the optimum operation parameters and make effective plan of klystron replacements. In addition, basic data for predicting the degradation tendency of klystron was acquired by comparing the characteristics of the used and used klystron.
Ono, Ayato; Takayanagi, Tomohiro; Ueno, Tomoaki*; Horino, Koki*; Yamamoto, Kazami; Kinsho, Michikazu
Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.399 - 403, 2019/07
J-PARC uses an ignitron switch as the klystron power source clover device and a thyratron switch as the kicker power system. Ignitron uses mercury, which is of limited use worldwide, and is expected to be discontinued in the future. Therefore, a semiconductor switch for ignitron substitution using a MOS gate thyristor is designed. In order to be used as a crowbar device, a switch capable of resisting an operating output of 120 kV, 40 kA, 50 us is required. We have realized an oval type substrate module that achieves an operating output of 3 kV, 40 kA, 50 us per substrate. In addition, we adopted a LTD circuit using SiC-MOSFET as an alternative switch for thyratron, and produced a radially symmetric pulse power supply circuit to which this circuit was applied. This circuit board achieves a rise of 250 ns or less, and a flat top of 1.5 us or more necessary for the RCS kicker power supply system, with a pulse output of 800 V and 2 kA per circuit board. We report on the power test results at 20 kV.
Takei, Hayanori; Furukawa, Kazuro*; Yano, Yoshiharu*; Ogawa, Yujiro*
Journal of Nuclear Science and Technology, 55(9), p.996 - 1008, 2018/09
Times Cited Count：2 Percentile：20.93(Nuclear Science & Technology)Experiences with existing high-power proton accelerators indicate that frequent beam trips are inevitable. One of the reasons for such frequent beam trips is the accidental interruption to protect accelerators against fatal failures. Generally, the failure frequency for the general machinery can be evaluated based on a reliability database for its components. On the other hand, the beam-trip frequency for the accidental interruption was not evaluated based on the reliability database because it has not yet been established. A principal reason for the lack of this reliability database is the inconsistency of data collection and analysis methods among laboratories. For example, there are at least three methods to estimate Mean Time Between accidental Interruptions (MTBI) for klystron systems. In the present study, the MTBI of the klystron systems of an electron/positron injector linac at the High Energy Accelerator Research Organization (KEK) was evaluated based on the reliability engineering method, in order to build the reliability database using the unified data collection and analysis method. As the result, the mean values of the MTBI by the traditional three methods were evaluated as 30.9, 32.0, and 50.4 hours. On the other hand, that by the reliability engineering method was evaluated as 57.3 hours, i.e., more than 1.14 times of the traditional results. Although these results are obviously different from traditional results, it appears that the present estimation based on the reliability engineering method is suitable for the MTBI of accelerator components as typified by the klystron system.
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
Hori, Toshihiko*; Chishiro, Etsuji; Yamazaki, Masayoshi*; Suzuki, Hiroyuki*; Hasegawa, Kazuo; Yoshida, Mitsuhiro*; Yamaguchi, Seiya*; Anami, Shozo*; Fukuda, Shigeki*
Proceedings of 2nd Annual Meeting of Particle Accelerator Society of Japan and 30th Linear Accelerator Meeting in Japan, p.239 - 241, 2005/07
no abstracts in English
Hori, Toshihiko*; Chishiro, Etsuji; Yamazaki, Masayoshi*; Suzuki, Hiroyuki*; Hasegawa, Kazuo
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.212 - 214, 2004/08
no abstracts in English
Hori, Toshihiko*; Chishiro, Etsuji; Yamazaki, Masayoshi*; Suzuki, Hiroyuki*; Hasegawa, Kazuo
KEK Proceedings 2003-16 (CD-ROM), 4 Pages, 2004/02
no abstracts in English
Yamazaki, Masayoshi*; Chishiro, Etsuji; Hori, Toshihiko*; Suzuki, Hiroyuki*; Hasegawa, Kazuo
Proceedings of 28th Linear Accelerator Meeting in Japan, p.363 - 365, 2003/08
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
Yamazaki, Masayoshi*; Chishiro, Etsuji; Suganuma, Kazuaki; Kobayashi, Tetsuya; Hori, Toshihiko*; Suzuki, Hiroyuki*; Hasegawa, Kazuo; Yoshikawa, Hiroshi
Proceedings of 27th Linear Accelerator Meeting in Japan, p.296 - 298, 2002/08
no abstracts in English
Maebara, Sunao
JAERI-Research 2000-061, 104 Pages, 2001/01
JAERI-Research-2000-061.pdf:9.71MB
no abstracts in English
Nomura, Masahiro; Toyama, Shinichi; ; ; Yamazaki, Yoshio; Hirano, Koichiro; Omura, Akiko
JNC TN9410 2000-007, 376 Pages, 2000/03
JNC-TN9410-2000-007.pdf:15.51MB
According to the Long-Term Program for Partitioning and Transmutation which was published by the Atomic Energy Commission in 1988, study on the transmutation using an electron accelerator, which was a part of the program, has been carried out in the O-arai Engineering Center. It is the study on converting radioactive fission products for example Strontium and Cesium to stable nuclides by photonuclear reaction caused by high energy gamma-ray made by an electron accelerator. It was thought that a 100mA-100MeV (10MW output power) accelerator would be needed in order to carry out the transmutation study in engineering phase. Therefore, development of the High-Current Electron Accelerator whose target had been 20mA-10MeV (200 kW output power) accelerator was carried out as development of elemental technologies on beam stabilization. The conceptual design of the accelerator was started in 1989. In March 1997, the main facility of this accelerator was completed. The test operation was carried out to confiim the performance of the accelerator from January, 1999 to December. As the result, an output of about 14 kW was achieved. In addition, the electron beam of 40 kW could be to accelerate in short time. In this report, the design, fabrication and evalution of performance of the facilities are presented.
Arakawa, Kazuo; Nakamura, Yoshiteru; Yokota, Wataru; Fukuda, Mitsuhiro; Nara, Takayuki; Agematsu, Takashi; Okumura, Susumu; Ishibori, Ikuo; Tamura, Hiroyuki
JAERI-Review 99-025, TIARA Annual Report 1998, p.254 - 256, 1999/10
no abstracts in English
