Improve long periodic ground motion evaluation with the epicenter on the border between Fukushima and Ibaraki prefectures in seismic design of nuclear facilities

Kirita, Fumio; Tominaga, Masahiro; Yamazaki, Toshihiko; Seshimo, Kazuyoshi; Uryu, Mitsuru

JAEA-Research 2022-006, 61 Pages, 2023/02

JAEA-Research-2022-006.pdf:6.24MB

Nuclear Fuel Cycle Engineering Laboratories (NCL) has been observing ground motion for a long time. On the border from northern Ibaraki prefecture to Fukushima prefecture, inland crustal earthquakes occur less frequently until the 2011 off the Pacific coast of Tohoku Earthquake (hereinafter referred to as Tohoku Earthquake). After Tohoku Earthquake, aftershocks have become more frequent in this area, and in the Hamadori region of Fukushima earthquake that a remarkable long periodic component was observed in the NCL seismic observation record. Until now there were no such things that long periodic components were observed at the observation points near the epicenter of April 2011 Fukushima earthquake, but it was thought basin structure in deep basement around the NCL affected the propagation process to NCL by reflection survey result. As basement structure of NCL affected the seismic wave propagation process, the seismic wave repeatedly reflects and refracts. For that reason, long periodic components of seismic waves may be possibly amplified. In this study, in order to refine the long periodic ground motion evaluation, using a three dimensional ground structure model (3D model) that can reflect the shape of the deep basement structure around the NCL. When modeling 3D ground structure which has a width of about 80km and a length of about 110km and ranges from the epicenter area of April 2011 Fukushima earthquake to the northern coastal area of Ibaraki prefecture modeled, improved the optimum ground structure model using multiple observation records and performed simulation analysis.

Beam test of a new RFQ for the J-PARC linac

Kondo, Yasuhiro; Morishita, Takatoshi; Yamazaki, Saishun; Hori, Toshihiko; Sawabe, Yuki; Takagi, Akira*

Proceedings of 27th International Linear Accelerator Conference (LINAC 2014) (Internet), p.267 - 269, 2014/12

http://accelconf.web.cern.ch/AccelConf/LINAC2014/papers/MOPP091.pdf

We performed a beam test of a new 324-MHz 3-MeV H RFQ (RFQ III) for the beam-current upgrade of the J-PARC linac. RFQ III is the first RFQ developed to meet the requirement of the J-PARC linac. The peak beam current is 50 mA, pulse length is 500 micro-sec, and the repetition is 25 Hz. Prior to the installation to the accelerator tunnel in summer of 2014, we constructed a test stand for off line testing of the new ion source and RFQ. Basic performances of RFQ III such as transmission and emittances were measured. In this paper, the beam test results are presented.

Present status of klystron power supply systems for J-PARC linac 2013

Kawamura, Masato*; Chishiro, Etsuji; Hori, Toshihiko; Shinozaki, Shinichi; Sato, Fumiaki; Fukui, Yuji*; Futatsukawa, Kenta*; Yamazaki, Masayoshi*; Sagawa, Ryu*; Miyajima, Noriyuki*; et al.

Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.605 - 607, 2014/06

http://www.pasj.jp/web_publish/pasj10/proceedings/PDF/SAP0/SAP061.pdf

This report describes the present status of the klystron power supply systems for the J-PARC linac. The systems for the 181 MeV linac were operated from September to May. A few breakdowns were occurred, and are described in this report. The new systems for the upgrade of the linac from 181MeV to 400 MeV have been installed until now, and the 3 HVDCPSs and the 3 anode modulators of the new systems have been operated. All the systems for 400 MeV linac will be operated in this autumn.

Status of J-PARC linac LLRF after the Tohoku Earthquake

Futatsukawa, Kenta*; Anami, Shozo*; Kobayashi, Tetsuya*; Fang, Z.*; Fukui, Yuji*; Michizono, Shinichiro*; Kawamura, Masato*; Sato, Fumiaki; Shinozaki, Shinichi; Chishiro, Etsuji; et al.

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.769 - 773, 2013/08

http://www.pasj.jp/web_publish/pasj9/proceedings/PDF/WEPS/WEPS124.pdf

no abstracts in English

Present status of klystron power supply systems for J-PARC linac 2012; Recovery from Earthquake Disaster, HVDCPS breakdown and energy upgrade

Kawamura, Masato*; Chishiro, Etsuji; Hori, Toshihiko; Shinozaki, Shinichi; Sato, Fumiaki; Fukui, Yuji*; Futatsukawa, Kenta*; Yamazaki, Masayoshi*; Sagawa, Ryu*; Yukitake, Mitsuteru*; et al.

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1243 - 1247, 2013/08

http://www.pasj.jp/web_publish/pasj9/proceedings/PDF/THPS/THPS110.pdf

no abstracts in English

High power test of 972 MHz waveguide systems for J-PARC Linac

Hori, Toshihiko; Yamazaki, Masayoshi; Yamaguchi, Seiya*; Hasegawa, Kazuo; Linac RF Group

NIFS-MEMO-55, p.289 - 292, 2008/03

no abstracts in English

High power test of the first ACS module for the J-PARC linac

Hirano, Koichiro; Ao, Hiroyuki; Morishita, Takatoshi; Asano, Hiroyuki; Hori, Toshihiko; Yamazaki, Masayoshi; Kobayashi, Tetsuya; Kubota, Chikashi*; Yamazaki, Yoshishige

Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.497 - 499, 2008/00

An ACS (Annular Coupled Structure) module has been developing for the 190-MeV to 400-MeV part of the J-PARC Linac. We have conducted the high power test of the first ACS module which consists of two accelerating tanks with 17 cells and a bridge tank with 9 cells. This paper describes results of the high power RF tests. The module achieved an average axial accelerating gradient of E0 = 4.5 MV/m at 1.8 MW RF input power, 0.6 ms pulse width, and 50 Hz repetition rate.

Present status of the 972 MHz RF test stand for J-PARC 2008

Hori, Toshihiko; Yamazaki, Masayoshi; Chishiro, Etsuji; Suzuki, Hiroyuki; Ao, Hiroyuki; Hirano, Koichiro; Hasegawa, Kazuo; Yamaguchi, Seiya*

Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.482 - 484, 2008/00

no abstracts in English

Confinement of microwave in RF equipment of J-PARC linac

Chishiro, Etsuji; Kobayashi, Tetsuya; Suzuki, Hiroyuki; Yamazaki, Masayoshi; Hori, Toshihiko; Fang, Z.*; Fukui, Yuji*; Kawamura, Masato*; Yamaguchi, Seiya*; Anami, Shozo*

Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM), p.519 - 521, 2007/00

High power RF sources have been installed in J-PARC linac building. The RF source is defined as the microwave application equipment by the Radio low, and is needed the charge minister's permission to offer the service. To pass the regulation, we sought the leakage point using a search coil and a bilog antenna, and stopped up the leak by contacting the metal connection completely. The result of measuring the microwave at the J-PARC site boundary, we confirmed the field strength which is less than permissible level.

Performance of J-PARC LINAC RF system

Kobayashi, Tetsuya; Chishiro, Etsuji; Hori, Toshihiko; Suzuki, Hiroyuki; Yamazaki, Masayoshi; Anami, Shozo*; Fang, Z.*; Fukui, Yuji*; Kawamura, Masato*; Michizono, Shinichiro*; et al.

Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM), p.510 - 512, 2007/00

High power operation of all the RF systems of J-PARC linac was started for the cavity conditioning in October 2006. Twenty 324-MHz klystrons have supplied the power to the accelerating cavities successfully. The beam commissioning was started in November 2006 then the acceleration to the design energy of 181 MeV was succeeded. The injection to the 3-GeV synchrotron will be started in September 2007. The RF control systems are performing according to the expectation, and the required field stability is satisfied.