Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Kamiya, Junichiro; Kotoku, Hirofumi*; Kurosawa, Shunta*; Takano, Kazuhiro; Yanagibashi, Toru*; Yamamoto, Kazami; Wada, Kaoru
Physical Review Accelerators and Beams (Internet), 24(8), p.083201_1 - 083201_23, 2021/08
Times Cited Count：0 Percentile：0.02(Physics, Nuclear)Through the operation of the vacuum system in J-PARC, it becomes evident that the high-power beam has more powerful effects on the vacuum system than expected. Those effects are the malfunction of vacuum equipment and the large pressure rise. The former is the failure of the turbomolecular pump (TMP) controller. The TMP itself is also damaged by a bearing crush due to a touch-down. We have developed a TMP controller that can connect with long cables of more than 200 m lengths to install the controller in a control room where there is no radiation influence. The TMP with high-strength bearing has been also developed. The latter is an extreme pressure rise with increasing the beam power. It is indicated that the pressure rise mechanism is a result of ion-stimulated gas desorption. It is finally confirmed that the dynamic pressure during the high-power beam is effectually suppressed by additionally installing the NEG pumps.
Kamiya, Junichiro; Yamamoto, Kazami; Takano, Kazuhiro; Kotoku, Hirofumi; Wada, Kaoru*; Yanagibashi, Toru*; Kurosawa, Shunta*
no journal, ,
The vacuum system in the rapid cycling synchrotron of Japan Proton Accelerator Research Complex was constructed based on the design concept considering the effect of a dynamic pressure caused by a high-power proton beam operation. However, the high-power beam operation clearly has more effects than expected at the time of the design. The dynamic pressure with the beamline pressure runaway characterized by an extreme pressure rise of more than orders of magnitude occurred during beam operation. A systematic data observation showed that the pressure rise mechanism is a result of the gas desorption from the wall triggered by the hitting of the residual gas molecules ionized by the proton beam. The numerical calculation based on that model well reproduced the measured dynamic pressure behaviors in the beam operation. The calculation also showed that a large pumping speed and a small surface density of the adsorbed molecules are required to suppress the pressure runaway.
Do, V. K.; Furuse, Takahiro; Ota, Yuki; Sano, Yuichi; Iwahashi, Hiroyuki; Homma, Shunta; Ichijo, Yurina; Kurosawa, Kiyoko*; Endo, Tsubasa*; Motoki, Yoshiaki*; et al.
no journal, ,
This paper presents an HCl-free chemical separation procedure for Sn recovery from concretes. Two pretreatment methods of solution samples followed by a proposed solid-phase extraction on TEVA resin were examined. The obtained results show that Sn can be highly recovered by the developed separation scheme with good reproducibility. The developed method is aimed at practical application to purification of Sn from concrete rubble for quantification of 
Sn by mass spectrometer.
Sn in radioactive rubbles by ICP-MS/MSOta, Yuki; Do, V. K.; Furuse, Takahiro; Sano, Yuichi; Iwahashi, Hiroyuki; Homma, Shunta; Ichijo, Yurina; Kurosawa, Kiyoko*; Endo, Tsubasa*; Motoki, Yoshiaki*; et al.
no journal, ,
no abstracts in English
Pd in radioactive rubbles by ICP-MS/MSIwahashi, Hiroyuki; Do, V. K.; Furuse, Takahiro; Ota, Yuki; Homma, Shunta; Kurosawa, Kiyoko*; Motoki, Yoshiaki*; Hirosawa, Takashi
no journal, ,
The radiometric determination of beta emitting Pd (half-life of 6.5 million years) requires a multiple-step chemical separation and a time-consuming radioactive measurement. Inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) with recent technological advances in interference removal by two quadrupole mass filters and a collision/reaction cell could be an alternative for highly sensitive analysis of long-lived radionuclides. In this study, we have developed an analytical method for the determination of Pd in concrete rubble by ICP-MS/MS combined with single-column chromatographic separation. A simplified procedure for the separation of Pd from concrete matrices was developed. The measurement condition was optimized to completely suppress the interference including the isobar Ag and the sample matrices. The application of the developed method to radioactive concrete rubble is under consideration.
Yamada, Ippei; Kamiya, Junichiro; Nakanoya, Takamitsu; Kurosawa, Shunta*; Yanagibashi, Toru*; Shiga, Takashi; Wada, Kaoru*; Warigai, Keiichi
no journal, ,
no abstracts in English
