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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/1.2
s 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.
Takayanagi, Tomohiro; Ono, Ayato; Horino, Koki*; Ueno, Tomoaki*; Sugita, Moe; Togashi, Tomohito; Yamamoto, Kazami; Kinsho, Michikazu
Proceedings of 18th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.53 - 57, 2021/10
We are developing the LTD semiconductor switch power supply, which combines SiC-MOSFET semiconductors and Linear Transformer Drivers (LTD) circuit to replace the kicker power supply in J-PARC. This power supply consists of two types of circuit boards: a main circuit board for forming rectangular pulses and a correction circuit board for compensating for flat-top droop, which enables high-voltage output and droop compensation for the number of stages connected in a hierarchical series. In addition to the main circuits of the thyratron, PFN, and end-clipper, which are the main circuit board is a single 400 mm 
430 mm board with a reflected wave absorption circuit that can reduce the beam impedance from the kicker magnet. In this study, we used 32 main circuit boards with 1.7 kV SiC-MOSFETs and 20 compensation boards with 100V MOSFETs to achieve the required 40 kV output rating as a kicker power supply. The evaluation results will be reported.
Takayanagi, Tomohiro; Ono, Ayato; Ueno, Tomoaki*; Horino, Koki*; Togashi, Tomohito; Yamamoto, Kazami; Kinsho, Michikazu; Koizumi, Isao*; Kawamata, Shunsuke*
JPS Conference Proceedings (Internet), 33, p.011020_1 - 011020_6, 2021/03
We are developing a new kicker power supply for J-PARC 3-GeV RCS (Rapid-Cycling Synchrotron) using the next generation power semiconductor SiC-MOSFET with high withstand voltage, low loss, and superior high frequency characteristics. The three major circuits adopted for the RCS kicker power supply, the thyratron switch, the PFN circuit of coaxial cable type, and the end clipper for reflection wave absorption, has been realized with a single modular circuit board based on the LTD circuit. The new kicker power supply realizes stable operation, miniaturization and energy saving by using power semiconductors. The required high voltage can be output by stacking the 800V/2kA modular circuit board in series. The details of circuit design and the results of achieving an output of half 20kV/2kA against the target specification of 40kV/2kA are presented here.
Takayanagi, Tomohiro; Ono, Ayato; Horino, Koki*; Ueno, Tomoaki*; Togashi, Tomohito; Yamamoto, Kazami; Kinsho, Michikazu
Proceedings of 17th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.25 - 28, 2020/09
We have been developing a semiconductor switch power supply to replace the RCS kicker power supply in J-PARC. A SiC MOSFET is used as a power semiconductor element, and a radially symmetric LTD circuit is used for the circuit board. The power supply consists of a combination of two types of circuit boards: a main circuit board, which includes the circuits of the thyratron, PFN and end clipper provided in RCS kicker power supplies, on a single module board, and a correction board, which compensates for flat-top droop. A single main circuit board can provide 800V/2kA output, and 52 main circuit boards and 20 correction boards have been used to successfully achieve the high voltage of 40kV and flat-top flatness of less than 
0.2%. Furthermore, a preliminary test of the dual-parallel circuit was conducted for a twin kicker power supply configuration, which is required for the RCS kicker power supply. The evaluation results and prospects are presented.
Takayanagi, Tomohiro; Ono, Ayato; Ueno, Tomoaki*; Horino, Koki*; Yamamoto, Kazami; Kinsho, Michikazu
Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.75 - 79, 2019/07
We will replace the Thyratron and Ignitron discharge type switch with a semiconductor switch capable of more stable operation. The thyratron alternative switch used by the kicker power supply manufactured the radial symmetric module substrate of the 800V/2kA output which was built by LTD circuit using SiC-MOSFET. By making the power transfer structure between module substrates stacked for high voltage output into a coaxial ring type, a further reduction in inductance is realized. We report the results of evaluating a pulse output of 20kV/1kA (final specification is 40kV/2kA). Ignitron, which is used as a high-power klystron clover switch, has the potential to be discontinued in the future because it uses mercury, which has limited use worldwide. LINAC's klystron clover switches require a working output of 50kV at 120kV/40kA. We fabricated 3kV/40kA oval type module substrate using MOS gate thyristor. Report on preliminary test results.
Takayanagi, Tomohiro; Ueno, Tomoaki*; Horino, Koki*; Yamamoto, Kazami; Kinsho, Michikazu
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.244 - 248, 2018/08
We will present the development of super high voltage short pulse switch power supply aiming at high performance of 3 GeV synchrotron accelerator pulsed electromagnet power supply. We are developing the switch power supply using SiC-MOSFET of the next generation power semiconductor which is higher in breakdown voltage, lower loss, and higher frequency operation than the current mainstream Si power semiconductors. The SiC conversion of semiconductors enables commercialization of thyratron substitute switches and power-saving small size switching power supplies. However, products that satisfy the specification of the thyratron (80kV/4kA) adopted for the J-PARC 3 GeV-RCS kicker power supply with one module have not been developed. Therefore, it is necessary to construct a circuit in which power semiconductors are multiplexed in series and parallel. In addition, the high-speed short pulse waveform required for the kicker power supply is designed with consideration of the circuit impedance such as inductance and stray capacitance separately from the performance improvement of the power semiconductor. Therefore, a circular radially symmetric circuit was constructed in which power semiconductors were concentrically arranged and the impedance of all parallel circuits could be made equal. As a result, waveform distortion caused by the difference in circuit impedance could be suppressed. This structure is adopted in the LTD circuit and it is indispensable for the development of semiconductor new kicker power supply. In this presentation, the results of the preliminary test and the evaluating test are reported.
Takayanagi, Tomohiro; Shibanuma, Yoshihiro*; Hofuku, Yuji*
no journal, ,
There is an area where a high radiation environment of 1 MGy per year at J-PARC. The device is required to have radiation resistance and the main parts are made of metal material, but the gasket etc. are made of rubber. However, the surface of EPDM rubber, which is known as radiation-resistant rubber, softens when irradiated with several MGy. Various sub-materials were selected from EPDM as raw materials, and samples in which the blending of the plasticizer was changed were prepared. The sample prepared with barium sulfate did not undergo surface softening such as hydrolysis or bleeding even after irradiation with 5 MGy. We report 11 kinds of rubber materials and evaluation results after gamma ray irradiation.
