Beam power and residual dose history of J-PARC RCS

Yamamoto, Kazami; Hotchi, Hideaki; Harada, Hiroyuki; Hayashi, Naoki; Kinsho, Michikazu; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Yoshimoto, Masahiro; Nakane, Yoshihiro; et al.

Progress in Nuclear Science and Technology (Internet), 4, p.238 - 242, 2014/04

https://doi.org/10.15669/pnst.4.238

A 3 GeV rapid cycling synchrotron (RCS) at J-PARC was commissioned in October 2007. Afterwards, the beam intensity was increased through a beam study, and the RCS has continuously provided a proton beam 100 kW to the neutron target since October 2009. With renewed efforts brought about by beam commissioning, we have reduced losses in the RCS and achieved low-loss operation. We present the history of the operational beam power and the residual dose distributions after operation.

Standard of radiation monitor based on LAN and PLC technology for J-PARC

Miyamoto, Yukihiro; Sakamaki, Tsuyoshi*; Maekawa, Osamu*; Nakashima, Hiroshi

JAERI-Tech 2004-054, 72 Pages, 2004/08

JAERI-Tech-2004-054.pdf:7.3MB

A standard is provided for the radiation monitor based on LAN (Local Area Network) and PLC (Programmable Logic Controller) technology at the introduction to the Japan Proton Accelerator Research Complex (J-PARC). The monitor consists of radiation measurement equipments and the central monitoring panel. The formers are installed in the radiation field, and the latter is installed in the control room and composed of PLC, which are connected with LAN. Extension of the existing standard and the conformity to the international standard were thought as important in providing the standard. The standard is expected to improve the compatibility, maintenancability and productivity of the components.

Design concept of radiation control system for the high intensity proton accelerator facility

Miyamoto, Yukihiro; Ikeno, Koichi; Akiyama, Shigenori*; Harada, Yasunori

JAERI-Tech 2002-086, 43 Pages, 2002/11

JAERI-Tech-2002-086.pdf:5.7MB

Description is given for the characteristic radiation environment for the High Intensity Proton Accelerator Facility and the design concept of the radiation control system of it. The facility is a large scale accelerator complex consisting of high energy proton accelerators carrying the highest beam intensity in the world and the related experimental facilities and therefore provides various issues relevant to the radiation environment. The present report describes the specifications for the radiation control system for the facility, determined in consideration of these characteristics.

Radiation safety at J-PARC

Nakashima, Hiroshi; Shibata, Tokushi; Sawahata, Kei; Miyamoto, Yukihiro; Nakane, Yoshihiro; Masukawa, Fumihiro; Seki, Kazunari; Sato, Koichi; Oguri, Tomomi*; Hirayama, Hideo*; et al.

no journal, , 

Aiming at studies on the latest basic science and the advancing nuclear technology, the J-PARC (Japan Proton Accelerator Research Complex) project is in progress, and the high-energy proton accelerator complex of the world highest intensity is under construction. Because of its very high beam power and its energy as well as the large-scale accelerator complex, we have encountered some difficult radiation problems in the radiation safety design. This paper reviews the radiation safety policy and methods for the design to overcome the problems on the radiation safety and the status of the radiation safety estimation for licensing of J-PARC.

Radiological protection monitoring for the high intensity proton accelerator facility

Miyamoto, Yukihiro

no journal, , 

no abstracts in English

Radioactivity and safety management of the mercury target system in J-PARC Materials and Life Science Facility

Nakazawa, Takashi; Sato, Koichi; Miyamoto, Yukihiro; Nakashima, Hiroshi; Kasugai, Yoshimi; Kai, Tetsuya; Oi, Motoki; Miura, Taichi*; Takahashi, Kazutoshi*

no journal, , 

Radioactive nuclide activated in the mercury target of Materials and Life-Science Experimental Facility of J-PARC, the measurement results of the dose rate around the mercury target and the safety measures for radiation are reported.

Release behavior of Hg in J-PARC Materials & Life Science Experimental Facility

Sato, Koichi; Masuyama, Koichi; Tajima, Takahiro; Yoshino, Koji; Seki, Kazunari; Kasugai, Yoshimi; Miyamoto, Yukihiro

no journal, , 

Various kinds of experiments on material and biological science have been carried out using neutrons and muons generated by bombarding the mercury and muon target with high-energy (3 GeV) and high-intense (1MW) protons in the Materials and Life Science Experimental Faculty (MLF) of Japan Proton Accelerator Complex (J-PAPC). It was found that radioactive nuclide of Hg induced in the mercury target during the beam operation was released to the environment via the ventilation system from the stack at specific times during maintenance periods. The weekly-average concentrations of Hg in the stack were 2.4 101.5 10 Bq/cm, which was much less than the legal limit by a factor of 1/10,000. The release behavior of Hg will be reported in the presentation.

Risk assessment on the off-normal event of the J-PARC neutron source

Kasugai, Yoshimi; Sato, Koichi; Masuyama, Koichi; Seki, Kazunari; Miyamoto, Yukihiro; Kai, Tetsuya; Harada, Masahide; Haga, Katsuhiro; Takada, Hiroshi

no journal, , 

no abstracts in English

Behavior of tritium release from a stainless vessel of the mercury target as a spallation neutron source

Kasugai, Yoshimi; Sato, Koichi; Takahashi, Kazutoshi*; Miyamoto, Yukihiro; Kai, Tetsuya; Harada, Masahide; Haga, Katsuhiro; Takada, Hiroshi

no journal, , 

A spallation neutron source of mercury has been operated in the Materials and Life Science Experimental Facility of J-PARC. A stainless vessel containing mercury during the operation has been exchanged periodically. During the exchange work, tritium release has been observed. The behavior and an analysis from a viewpoint of tritium absorption and emission from stainless steel are reported.