Operational characteristics of the J-PARC cryogenic hydrogen system for a spallation neutron source

Tatsumoto, Hideki; Otsu, Kiichi; Aso, Tomokazu; Kawakami, Yoshihiko; Teshigawara, Makoto

AIP Conference Proceedings 1573, p.66 - 73, 2014/01

https://doi.org/10.1063/1.4860684

The J-PARC cryogenic hydrogen system provides supercritical hydrogen provides to three moderators. A heater for the thermal compensation and a cryogenic accumulator are prepared to mitigate a pressure fluctuation. A feed temperature should be lower than 20 K and its fluctuation should be within 0.25 K to provide cold pulsed neutron beams of a higher neutronic performance. An ortho-para hydrogen convertor is installed to maintain the para-hydrogen concentration of more than 99.0%. In this study, it is confirmed that para-hydrogen always exists in the equilibrium concentration during the cool-down process. Propagation characteristics of temperature fluctuation caused by sudden heater power variations were studied. An allowable temperature fluctuation caused by the heater control approach is determined to be 1.05 K. It is found that the heater control would be applicable for the 1-MW proton beam operation by extrapolating from the experimental data for on-beam commissioning.

Production of a low-energy radioactive nuclear beam with high purity using JAERI-RMS

Ishiyama, Hironobu*; Ishikawa, Tomoko*; Hashimoto, Takashi; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Imai, Nobuaki*; Miyatake, Hiroari; Tanaka, Masahiko*; Fuchi, Yoshihide*; Yoshikawa, Nobuharu*; et al.

Nuclear Instruments and Methods in Physics Research A, 560(2), p.366 - 372, 2006/05

https://doi.org/10.1016/j.nima.2005.12.244

Thanks to the nature of inverse transfer-reactions, low-energy radioactive nuclear beams in light neutron-rich region were produced. The mass-separation and velocity-separation of the JAERI recoil mass-separator help to form high purity beams. The beams of Li, B, and N-RNBs are utilized to the experiments, so far, with those beam intensities and purities of 1.410 pps and 99, 7.810 pps and 98, and 4.710 pps and 98.5, respectively.

Crack extension analysis under pressurized thermal shock loading by ADINA

Isozaki, Toshikuni; Shibata, Katsuyuki; *; *

JAERI-Research 96-039, 133 Pages, 1996/07

JAERI-Research-96-039.pdf:3.85MB

no abstracts in English

Development of diagnostic methodology of degradation of electric wire and cables by a stress-strain response measurement

Yagi, Toshiaki; Morita, Yosuke; Kawakami, Waichiro; *; *; *; *

EIM-90-124, p.65 - 74, 1990/12

no abstracts in English

Effect of radiation oxidation on various properties of insulating materials

Kusama, Yasuo; Kawakami, Waichiro; *; *

EIM-89-116, p.21 - 29, 1989/12

no abstracts in English

Seismic Analysis of the JT-60,2; Dynamic Responce Analysis

; ; *; *

JAERI-M 8350, 39 Pages, 1979/07

JAERI-M-8350.pdf:1.1MB

no abstracts in English

Direct measurements of astrophysical nuclear reaction rates on light neutron-rich nuclei at TRIAC and JAEA-RMS

Miyatake, Hiroari; Ishiyama, Hironobu*; Watanabe, Yutaka*; Hirayama, Yoshikazu*; Imai, Nobuaki*; Tanaka, Masahiko*; Yoshikawa, Nobuharu*; Jeong, S.-C.*; Fuchi, Yoshihide*; Nomura, Toru*; et al.

no journal, , 

no abstracts in English

Development of a centrifugal hydrogen pump for the cryogenic hydrogen system in J-PARC

Aso, Tomokazu; Tatsumoto, Hideki; Otsu, Kiichi; Uehara, Toshiaki; Kawakami, Yoshihiko; Sakurayama, Hisashi; Futakawa, Masatoshi; Ushijima, Isamu*; Yoshinaga, Seiichiro*

no journal, , 

A centrifugal hydrogen pump that is a foil type self acting gas bearing had developed for the cryogenic hydrogen system in J-PARC, and the performance test was carried out in the system operation. The cryogenic hydrogen system plays a role in supplying supercritical hydrogen at a temperature of around 20 K and pressure of 1.5 MPa to three moderators and removing the nuclear heating of 3.8 kW at a proton beam of 1 MW from accelerators. In order to satisfy the neutronic performance, the temperature difference through the moderator should be reduced below 3 K. Therefore, cryogenic supercritical hydrogen should be circulated with the mass flow rate more than 160 g/s. We confirmed the characteristics of the pump satisfy the required performance.

Using CO reaction to achieve mass-spectrometric discrimination for Pu isotopic analysis with inductively coupled plasma-mass spectrometry

Matsueda, Makoto; Kawakami, Tomohiko*; Koarai, Kazuma; Terashima, Motoki; Fujiwara, Kenso; Iijima, Kazuki; Furukawa, Makoto*; Takagai, Yoshitaka*

no journal, , 

Inductively coupled plasma tandem mass spectrometry with CO gas reactions in a dynamic reaction cell almost eliminated the background noise intensity produced by isobaric interference from isotopes originating from actinides such as Am, Cm, and U at the locations (m/z) of significant Pu isotopes (Pu, Pu, Pu, Pu, and Pu).

Simultaneous determination of actinide isotopes by inductively coupled plasma-mass spectrometry incorporating cascade separation step

Matsueda, Makoto; Kawakami, Tomohiko*; Teruyama, Yuko*; Terashima, Motoki; Iijima, Kazuki; Furukawa, Makoto*; Takagai, Yoshitaka*

no journal, , 

Determination of actinides (e.g., Th, U, Np, Pu, Am, Cm) in contaminated water and nuclear waste is important for decommissioning the Fukushima Daiichi Nuclear Power Station. However, traditional radiochemical analysis needs a time-consuming process and large effort. ICP-MS has the potential of rapid determination by simultaneous detection of actinides, while many isobaric interferences prevent the quantification. In this study, we developed an automatic analysis method using ICP-MS incorporating cascade separation steps (solid phase separation and gas phase reaction in the dynamic reaction cell) to simultaneously determine actinides.