Present status of personnel protection system at J-PARC

Kikuzawa, Nobuhiro; Niki, Kazuaki*; Yamamoto, Noboru*; Hayashi, Naoki; Adachi, Masatoshi*; Watanabe, Kazuhiko*

Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.877 - 880, 2019/07

https://www.pasj.jp/web_publish/pasj2019/proceedings/index.html

Interlock system of J-PARC is classified into a personnel protection system (PPS) for human safety and a machine protection system (MPS) for protecting equipment. The PPS of the J-PARC accelerator started from the operation at Linac in 2006 and was completed by the MR operation in 2008. In the next 10 years, some improvements have been made, such as updating video monitoring systems and establishing new interlocks. In addition to describing recent operations including these updatings, this paper reports the current status of inspections and maintenance conducted to maintain and improve reliability.

Operation status of J-PARC timing system and future plan

Kamikubota, Norihiko*; Kikuzawa, Nobuhiro; Tamura, Fumihiko; Yamamoto, Noboru*

Proceedings of 15th International Conference on Accelerator and Large Experimental Physics Control Systems (ICALEPCS 2015) (Internet), p.988 - 991, 2016/01

https://doi.org/10.18429/JACoW-ICALEPCS2015-WEPGF121

The beam commissioning of J-PARC started in November, 2006. Since then, the timing system of J-PARC accelerator complex has contributed stable beam operations of three accelerators: a 400-MeV linac (LI), a 3-GeV rapid cycling synchrotron (RCS), and a 50-GeV synchrotron (MR). The timing system handles two different repetition cycles: 25 Hz for LI and RCS, and 2.48-6.00 sec. for MR (MR cycle). In addition, the timing system is capable to provide beams to two different experimental facilities in single MR cycle: Material and Life Science Experimental Facility (MLF) and Neutrino Experimental Facility (NU), or, MLF and Hadron Experimental Facility (HD). Recently, a plan to introduce a new facility, Accelerator-Driven Transmutation Experimental Facility (ADS), around 2018, has been discussed. This paper reviews the 8-year operation experience of the J-PARC timing system, followed by a present perspective of upgrade studies.

High-speed classification of coherent X-ray diffraction Patterns on the K computer for high-resolution single biomolecule imaging

Tokuhisa, Atsushi*; Arai, Junya*; Jochi, Yasumasa*; Ono, Yoshiyuki*; Kameyama, Toyohisa*; Yamamoto, Keiji*; Hatanaka, Masayuki*; Gerofi, B.*; Shimada, Akio*; Kurokawa, Motoyoshi*; et al.

Journal of Synchrotron Radiation, 20(6), p.899 - 904, 2013/11

https://doi.org/10.1107/S0909049513022152

Development of Tc production from (n, ) Mo

Tanase, Masakazu*; Shiina, Takayuki*; Kimura, Akihiro; Nishikata, Kaori; Fujisaki, Saburo*; Ota, Akio*; Kobayashi, Masaaki*; Yamamoto, Asaki*; Kawauchi, Yukimasa*; Tsuchiya, Kunihiko; et al.

Proceedings of 5th International Symposium on Material Testing Reactors (ISMTR-5) (Internet), 9 Pages, 2012/10

http://www.murr.missouri.edu/ismtr/papercall/Papers/Chiyoda%20Technol/Tanase_M=PAPER_Dev%20of%20Tc99m%20Prod%20from%20n-g%20Mo99.pdf

Tc is used as a radiopharmaceutical and manufactured from the parent nuclide of Mo. Extraction method of Tc from (n, ) Mo have been developed, as a part of the industrial use expansion after JMTR will re-start. In this research, the method proposed would be applicable to a practical production of Tc obtained from (n, ) Mo in large quantities. The method proposed would be applicable to a practical production of Tc obtained from (n, ) Mo in large quantities.

Status of beam loss evaluation at J-PARC linac

Miura, Akihiko; Sako, Hiroyuki; Yamamoto, Kazami; Kikuzawa, Nobuhiro; Maruta, Tomofumi; Sato, Susumu; Imai, Kenichi; Adachi, Satoshi; Sugimura, Hitoshi; Igarashi, Zenei*; et al.

Proceedings of 25th International Linear Accelerator Conference (LINAC 2010) (CD-ROM), p.590 - 592, 2010/09

http://accelconf.web.cern.ch/AccelConf/LINAC2010/papers/tup076.pdf

Ar-CO gas proportional counters are employed for the measurement of beam loss in the current linac operation, but they are also sensitive to background noise of X-ray emitted from RF cavities. In SDTL section, protons, secondary hadrons and rays would be mainly generated as a beam loss, but it is not easy to estimate real beam loss using the proportional counter. The plastic scintillation counters with less X-ray sensitivity and He proportional counters with high thermal neutron sensitivity will be also employed to measure the beam loss. This paper reports the signals obtained during the beam operation using the Ar-CO gas proportional counter and the plastic scintillation counter. Finally, a measurement of emission position and angle distributions of protons due to negative hydrogen ion (H) beam loss is being planed. This plan is introduced and this result would lead to clarify the source of beam loss.

Radiation resistance of organic materials in superconducting magnets at 77 K; Mechanical properties

Nakamoto, Tatsushi*; Ohata, Hirokatsu*; Ogitsu, Toru*; Kimura, Nobuhiro*; Makida, Yasuhiro*; Yamamoto, Akira*; Idesaki, Akira; Gokan, Mayo*; Morishita, Norio; Ito, Hisayoshi

JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 31, 2007/02

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2006-042.pdf

Radiation resistance of organic materials used in superconducting magnets for a 50 GeV - 750 kW proton beam line for the J-PARC neutrino experiment was studied with respect to mechanical properties. Specimens cooled at a liquid nitrogen temperature of 77 K were irradiated by rays. The flexural strength of glass-fiber reinforced plastics (GFRPs), the tear strength of polyimide films and the tensile strength of adhesive films were evaluated. It was verified that the organic materials used in the superconducting magnets have the sufficient radiation resistance, and the degradation of thier mechanical properties after the 10 years operation was estimated to be negligible.

Reaction, transport and settling behavior of lead-bismuth eutectic in flowing liquid sodium

Miyahara, Shinya; Ohno, Shuji; Yamamoto, Nobuhiro; Saito, Junichi; Hirabayashi, Masaru

Proceedings of 14th International Conference on Nuclear Engineering (ICONE-14) (CD-ROM), 7 Pages, 2006/07

The experimental study has been carried out to investigate reaction, transport and settling behavior of lead-bismuth eutectic (LBE) in flowing liquid sodium. In the test, 168 g of LBE were poured into flowing sodium from the top of a vertical-type sodium loop which contained 23.2 kg of sodium. The initial temperature of LBE and sodium was 673 K. The flow rate and the maximum velocity of sodium in the loop were controlled and measured at 20 dm/min and 1 m/sec, respectively, using an electro-magnetic pump and an electro-magnetic flow meter. The sodium loop has a settling chamber at the lower part to investigate the concentration decrease behavior of solid particle reaction products in the sodium due to the settling effect. The concentration was measured by sodium sampling from the 11 positions of the loop during the experiment and its post-test chemical analysis. The temperature changes at the various parts of the loop were also measured during the experiment by thermo-couples attached on the outer surface of the loop. Ultrasonic detectors were attached on the outer surface of the loop below the position of a LBE pour nozzle to demonstrate the utility as a leak detector.

Mechanical properties of organic materials used in superconducting magnets irradiated by gamma rays at liquid nitrogen temperature

Nakamoto, Tatsushi*; Idesaki, Akira; Morishita, Norio; Ito, Hisayoshi; Kamiya, Tomihiro; Kimura, Nobuhiro*; Makida, Yasuhiro*; Ogitsu, Toru*; Ohata, Hirokatsu*; Yamamoto, Akira*

AIP Conference Proceedings 824, p.225 - 232, 2006/03

https://doi.org/10.1063/1.2192355

Radiation resistance with respect to mechanical properties of organic materials used in the superconducting magnets for the 50 GeV - 750 kW proton beam line for the J-PARC neutrino experiment was studied. Specimens cooled at liquid nitrogen temperature of 77 K were irradiated by gamma rays beyond 10 MGy. The flexural strength of glass-fiber reinforced plastics (GFRPs), the tear strength of polyimide films and the tensile lap-shear strength of adhesive films were evaluated. It was verified that the organic materials used in the superconducting magnet have a sufficient radiation resistance, and the degradation of their mechanical properties after 10 years operation was estimated to be negligible.

Progress in physics and technology developments for the modification of JT-60

Tamai, Hiroshi; Matsukawa, Makoto; Kurita, Genichi; Hayashi, Nobuhiko; Urata, Kazuhiro*; Miura, Yushi; Kizu, Kaname; Tsuchiya, Katsuhiko; Morioka, Atsuhiko; Kudo, Yusuke; et al.

Plasma Science and Technology, 6(1), p.2141 - 2150, 2004/02

https://doi.org/10.1088/1009-0630/6/1/006

The dominant issue for the the modification program of JT-60 (JT-60SC) is to demonstrate the steady state reactor relevant plasma operation. Physics design on plasma parameters, operation scenarios, and the plasma control method are investigated for the achievement of high-. Engineering design and the R&D on the superconducting magnet coils, radiation shield, and vacuum vessel are performed. Recent progress in such physics and technology developments is presented.

Objectives and design of the JT-60 superconducting tokamak

Ishida, Shinichi; Abe, Katsunori*; Ando, Akira*; Cho, T.*; Fujii, Tsuneyuki; Fujita, Takaaki; Goto, Seiichi*; Hanada, Kazuaki*; Hatayama, Akiyoshi*; Hino, Tomoaki*; et al.

Nuclear Fusion, 43(7), p.606 - 613, 2003/07

https://doi.org/10.1088/0029-5515/43/7/314

no abstracts in English