Design and actual performance of J-PARC 3 GeV rapid cycling synchrotron for high-intensity operation

Yamamoto, Kazami; Kinsho, Michikazu; Hayashi, Naoki; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Tani, Norio; Takayanagi, Tomohiro; Kamiya, Junichiro; Shobuda, Yoshihiro; et al.

Journal of Nuclear Science and Technology, 59(9), p.1174 - 1205, 2022/09

https://doi.org/10.1080/00223131.2022.2038301

In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, the RCS was elaborately designed. After starting the RCS operation, we carefully verified the validity of its design and made certain improvements to establish a reliable operation at higher power as possible. Consequently, we demonstrated beam operation at a high power, namely, 1 MW. We then summarized the design, actual performance, and improvements of the RCS to achieve a 1 MW beam.

Interlocked events of beam loss monitors at the J-PARC linac

Hayashi, Naoki; Kikuzawa, Nobuhiro; Miura, Akihiko; Futatsukawa, Kenta*; Miyao, Tomoaki*

Proceedings of 14th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.540 - 544, 2017/12

http://www.pasj.jp/web_publish/pasj2017/proceedings/PDF/TUP0/TUP077.pdf

The J-PARC linac operation is stable, however, the numbers of interlocked events due to single beam loss monitor (BLMP) is increasing. Recently, the counts is comparable to the number of RFQ trip, and a measure has been required for improvement of the operation efficiency. Thus, every event data has been analyzed and classified into three categories. It is found that there are characteristic signal or pattern of BLMP for every categories. Although the linac BLMP detector is standard, its setting parameters are differ from those of other two synchrotrons in the J-PARC. To optimize time resolution, the input impedance of its pre-amplifier is selected to be 50 and interlock is defined in raw signal height and width not integral signal of BLMP. Some new parameters has been tried to reduce unnecessary interlock.

Beam loss mitigation by the modification of the beam pulse definition in the J-PARC LINAC

Sawabe, Yuki; Maruta, Tomofumi*; Liu, Y.*; Miura, Akihiko; Miyao, Tomoaki*; Ishiyama, Tatsuya; Kikuzawa, Nobuhiro; Hayashi, Naoki

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1202 - 1205, 2015/09

http://www.pasj.jp/web_publish/pasj2015/proceedings/PDF/THP0/THP080.pdf

no abstracts in English

Study on natural convection in core barrel; Experimental and numerical results for band type spacer pads

Hayashi, Kenji; Kawamata, Nobuhiro; Kamide, Hideki

JNC TN9400 2003-043, 64 Pages, 2003/03

JNC-TN9400-2003-043.pdf:2.67MB

In a fast reactor an lnter-Wrapper Flow (IWF)is one of significant phenomena for decay heat removal under natural circulation condition, when a direct reactor auxiliary cooling system (DRACS)is adopted for decay heat removal system. Cold coolant provided by dipped heat exchangers (DHX) of DRACS can penetrate into the core barrel (region between the subassemblies)and it makes natural convection in the core barrel. Such IWF will depend on a spacer pad geometry of subassemblies. Water experiment, TRIF(Test Rig for inter-wrapper Flow),was carried out for IWF in a reactor core. The test section modeled a 1/12th sector of the core and upper plenum of reactor vesse1. Experimental parameters were the spacer pad geometry and flow path geometries connecting the upper plenum and core barrel. Numerical simulation using AQUA code was also performed to confirm applicability of a simulation method. An experimental series using a button type spacer pad had been carried out. Here a band type spacer pad was examined. Temperatures at subassembly wall were measured with parameter of the flow path geometries; one was a connection pipe between the upper plenum and core barrel and the other was flow hole in core former plates between the outermost subassemblies and the core barrel. It was found that these flow paths were effective to remove heat in the core in case of the band type spacer pad. A general purpose three dimensional analysis code, AQUA,was applied to the experimental analysis. Each subassembly and inter wrapper gap region were modeled by slab mesh geometry. Pressure loss coefficient at the spacer pad was set based on the geometry. The numerical simulation results were in good agreement with measured temperature profiles in the core.

Application of Atomic Energy Grid InfraStructure (AEGIS) to nuclear fusion research

Suzuki, Yoshio; Kushida, Noriyuki; Yamagishi, Nobuhiro; Nakajima, Kohei; Minami, Takahiro; Matsumoto, Nobuko; Aoyagi, Tetsuo; Nakajima, Norihiro; Iba, Katsuyuki*; Hayashi, Nobuhiko; et al.

no journal, , 

no abstracts in English

Half-life measurements of neutron-deficient isotopes using laser Compton scattering -rays at NewSUBARU

Hayakawa, Takehito; Shizuma, Toshiyuki; Miyamoto, Shuji*; Amano, Sho*; Horikawa, Ken*; Hayashi, Yukio; Kawase, Keigo; Kando, Masaki; Kikuzawa, Nobuhiro; Chiba, Satoshi; et al.

no journal, , 

no abstracts in English

Quest for microorganisms existing at high atmosphere and space

Yokobori, Shinichi*; Yang, Y.*; Sugino, Tomohiro*; Kawaguchi, Yuko*; Itahashi, Shiho*; Fujisaki, Kenta*; Fushimi, Hidehiko*; Hasegawa, Sunao*; Hashimoto, Hirofumi*; Hayashi, Nobuhiro*; et al.

no journal, , 

Tanpopo: astrobiology exposure and micrometeoroid-capture experiments; On the capture and space exposure experiments

Yokobori, Shinichi*; Yang, Y.*; Kawaguchi, Yuko*; Sugino, Tomohiro*; Takahashi, Yuta*; Narumi, Issei; Takahashi, Yuichi*; Hayashi, Nobuhiro*; Yoshimura, Yoshitaka*; Tabata, Makoto*; et al.

no journal, , 

no abstracts in English

Microbe space exposure experiments at International Space Station (ISS) in the mission "Tanpopo"

Yokobori, Shinichi*; Yang, Y.*; Sugino, Tomohiro*; Kawaguchi, Yuko*; Takahashi, Yuta*; Narumi, Issei; Hashimoto, Hirofumi*; Hayashi, Nobuhiro*; Imai, Eiichi*; Kawai, Hideyuki*; et al.

no journal, , 

TANPOPO: astrobiology exposure and micrometeoroid capture experiments; Proposed experiments at the exposure facility of ISS-JEM

Yokobori, Shinichi*; Hashimoto, Hirofumi*; Hayashi, Nobuhiro*; Imai, Eiichi*; Kawai, Hideyuki*; Kobayashi, Kensei*; Mita, Hajime*; Nakagawa, Kazumichi*; Narumi, Issei; Okudaira, Kyoko*; et al.

no journal, ,