Development of a prototype GEM TPC with a gating grid for an H-dibaryon search experiment at J-PARC

Sako, Hiroyuki; Sugimura, Hitoshi; Ahn, J. K.*; Han, Y.*; Hasegawa, Shoichi; Hwang, S. H.*; Ichikawa, Yudai; Imai, Kenichi; Kiuchi, Ryuta*; Ozawa, Kyoichiro; et al.

Nuclear Instruments and Methods in Physics Research A, 763, p.65 - 81, 2014/11

https://doi.org/10.1016/j.nima.2014.06.007

We developed a prototype TPC for an H-dibaryon search experiment at J-PARC. To investigate its performance, we conducted tests with Ar-CH (90:10) and Ar-CF (95:5), where the former is mainly used. The detection efficiency was measured to be 98% at the beam rate up to cps/cm, and 90% at the rate of cps/cm. Based on the measured horizontal resolution of 0.19-0.46 mm at the drift length of 5-20 cm, the position resolution of better than 0.3 mm is estimated in 1 T magnetic field. The ion backflow fraction was measured to be 5% and reduced up to 3% at the gain of . The horizontal position distortion due to ion backflow in the gate operation was suppressed within mm at the beam rates up to cps/cm. On the other hand, the distortion with the gate open was measured to be mm. The distortion in the final experiment is estimated to be mm.

Search for the pentaquark via reaction at 1.92 GeV/

Shirotori, Kotaro*; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; Sugimura, Hitoshi; Ichikawa, Yudai; Tanida, Kiyoshi; 61 of others*

Physical Review Letters, 109(13), p.132002_1 - 132002_5, 2012/09

https://doi.org/10.1103/PhysRevLett.109.132002

The pentaquark baryon was searched for via the reaction at 1.92 GeV/ with a missing mass resolution of 1.4 MeV/c (FWHM) at J-PARC. No peak structure corresponding to the mass was observed. The upper limit of the production cross section is obtained to be 0.26b/sr in the pentaquark mass region.

Intergranular corrosion mechanism of ultra-low carbon type 304 stainless steel in a nuclear reprocessing plant

Ueno, Fumiyoshi; Kato, Chiaki; Motooka, Takafumi; Ichikawa, Shiro*; Yamamoto, Masahiro

Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM), p.1389 - 1393, 2007/09

Authors were aimed for development of life evaluation method of components and clarification of corrosion mechanism of the components in nuclear reprocessing plant. Corrosion behavior of heat exchanger tubes in the reduced pressure evaporator made by ultra-low carbon type 304ULC stainless steel was studied. A simplified mock-up test apparatus was used for corrosion test with long-term test duration. Following results were obtained. The corrosion rates were increased from beginning of the test to more than 25,000 hours and then corrosion rate was reached to constant. From the measurement results of intergranular penetration depths, it was thought that intergranular corrosion was progressed on entire grain boundary around a grain and then the grain dropped out to the solution.

None

Yasuda, Hitoshi*; Nodaka, Masayuki*; Mantani, Kenichi*; Kamikubo, Fumio*; Furuya, Takashi*; Ichikawa, Shiro*

PNC TJ8058 97-007, 583 Pages, 1997/03

PNC-TJ8058-97-007.pdf:38.05MB

None

TBP reversed-phase extraction chromatography of Rutherfordium in the HCl solution

Toyoshima, Atsushi; Haba, Hiromitsu*; Tsukada, Kazuaki; Asai, Masato; Akiyama, Kazuhiko*; Ishii, Yasuo; Tome, Hayato*; Nishinaka, Ichiro; Sato, Tetsuya; Ichikawa, Takatoshi; et al.

no journal, , 

no abstracts in English

Corrosion and degradation mechanism of materials used in the nuclear reprocessing plant, 1; Propagation of corrosion loss in stainless steel used in the reprocessing plant

Ichikawa, Shiro; Motooka, Takafumi; Kato, Chiaki; Yamamoto, Masahiro; Kiuchi, Kiyoshi; Ueno, Fumiyoshi

no journal, , 

We have carried out a study of the life evaluation method of stainless steel components in nuclear fuel reprocessing plant, such as evaporators and concentrators, under boiling nitric acid environments. In this study, long term corrosion test of heat tubes in the mock-up level test piece of a concentrator (Low Tritiated Acid Recovery) was made, and the corrosion mechanism and behavior under boiling nitric acid were studied.

Intergranular corrosion mechanism of ultra low carbon type 304 stainless steel in a simulated solution of nuclear fuel reprocessing process

Yamamoto, Masahiro; Ichikawa, Shiro*; Ueno, Fumiyoshi; Kiuchi, Kiyoshi

no journal, , 

A reprocessing process which extracts burnable elements from a spent nuclear fuel is expected to get a high energy efficiency of nuclear energy system. In the reprocessing plant, there exist some units using boiling nitric acid solutions. The solutions include Uranium, trans-uranium elements and fission products. Boiling nitric acid is very corrosive reagent and accelerates corrosion remarkably. For ensuring the reliability of the reprocessing plant, it is important to clarify the corrosion phenomena of the plants components, vessels and pipes, etc. Corrosion phenomena in the reprocessing plants have been reported by some researchers. These approaches were examined in the laboratory with small size samples. There exist some differences between small samples and real plant materials in temperatures, heat transfer etc. To clarify these problems, a large size simulation test has been conducted. In this report, test results and intergranular corrosion mechanism of sample was discussed.

Analysis of penetration depths of stainless steel in simulated solution for fuel reprocessing process

Ueno, Fumiyoshi; Yamamoto, Masahiro; Kato, Chiaki; Ichikawa, Shiro*

no journal, , 

Corrosion tendency in boiling nitric acid environment of a stainless steel evaporator has been studied to contribute to life evaluation against long term corrosion of one of components in a nuclear fuel reprocessing plant. In this study, corrosion test in nitric acid solution was performed for long term using a large scale mock-up test specimen, grain boundary penetration depths of heat exchanger tubes were measured by microscopic observation in its cross sections and were analyzed by statistical method. The other hand, penetration depth of heat exchanger tubes were carried out by nondestructive method, maximum penetration depth was estimated by statistical analysis. These two quantities were compared with each other. As the results, it was indicated that maximum penetration depth was useful to evaluate corrosion life of heat exchanger tube.