New SiC kicker power supply for J-PARC

Takayanagi, Tomohiro; Ono, Ayato; Sugita, Moe; Yamamoto, Kazami; Oguri, Hidetomo; Kinsho, Michikazu; Horino, Koki*; Ueno, Tomoaki*; Oda, Kodai*; Tokuchi, Akira*; et al.

Journal of Physics; Conference Series, 2687(8), p.082021_1 - 082021_7, 2024/01

https://doi.org/10.1088/1742-6596/2687/8/082021

A new kicker power supply using SiC-MOSFETs is under development at J-PARC. The base circuit uses an induction voltage superposition circuit of the LTD method, and the semiconductor module circuit consists of a radial symmetry type that achieves low noise. The three main parts of an existing kicker power supply, the thyratron, PFN circuit, and end clipper, can be configured in a single module circuit. The power supply consists of a main circuit module board that forms a trapezoidal pulse and a correction circuit module board that compensates for droop of the flat section. The thirty-two main circuit module boards and twenty correction circuit module boards are connected in series in a hierarchical manner to achieve the waveform specifications required for J-PARC RCS kicker power supplies. In addition, an insulating cylinder for conductors has been developed that suppresses corona discharge and withstands continuous operation for long periods of time.

Semiconductor pulse power supplies for accelerators at J-PARC

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.

Detecting halfmetallic electronic structures of spintronic materials in a magnetic field

Fujiwara, Hidenori*; Umetsu, Rie*; Kuroda, Fumiaki*; Miyawaki, Jun*; Kashiuchi, Toshiyuki*; Nishimoto, Kohei*; Nagai, Kodai*; Sekiyama, Akira*; Irizawa, Akinori*; Takeda, Yukiharu; et al.

Scientific Reports (Internet), 11(1), p.18654_1 - 18654_9, 2021/09

https://doi.org/10.1038/s41598-021-97992-z

R&D of advanced stainless steels for BWR fuel claddings, 3-7; Evaluation of irradiation behavior

Hashimoto, Naoyuki*; Toyoda, Kodai*; Tang, Y.*; Sakamoto, Kan*; Yamashita, Shinichiro

no journal, , 

To investigate irradiation stability of FeCrAl-ODS stainless steel (Fe-12Cr-6Al-0.5Ti-0.4Zr -0.24Ex.O-0.5YO), the ion irradiation was carried out recrystallized and extruded materials. The recrystallized and extruded materials were irradiated at TIARA of Quantum and Radiological Science and Technology (Takasaki) and DuET of Kyoto University, respectively. The irradiated sample was thinned by FIB and microstructure observation was performed using 200 keV transmission electron microscopy. To grasp formation and grown-up behavior of cavity under irradiation, the migration energy in cavity was experimentally drawn out the irradiation experiment. Energy by the density functional theory was calculated in consideration of the interaction between vacancy and Al atom.