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Kamiya, Junichiro; Kinsho, Michikazu; Ogiwara, Norio*; Sakurai, Mitsuru*; Mabuchi, Takuya*; Wada, Kaoru*
Vacuum and Surface Science, 62(8), p.476 - 485, 2019/08
J-PARC 3GeV rapid cycling synchrotron (RCS) is one of the highest beam power proton accelerators. Challenges for achieving low pressure region in ultra-high vacuum (UHV) in the beam line are the large outgassing source. We focused turbo molecular pumps (TMP) as maing pump because it can evacuate the continuous and additional outgassing with large pumping speed in wide pressure range. It is also possible to evacuate from low vacuum to UHV with only a few hours by using TMP, which ensures users' experimental time after vacuum device maintenance. During more than 10 years operation of the vacuum system, many experiences have been accumulated about the usage of TMP in RCS. In this presentation, we discussed about validity of TMP as main pump in high power proton beam accelerator by showing the performance of the beam line pressure during the beam operation. Further, in anticipation of upgrade higher beam power more than 1 MW, validity of a combination of TMP and NEG pump will be mentioned.
Yamada, Ippei; Ogiwara, Norio*; Hikichi, Yusuke*; Kamiya, Junichiro; Kinsho, Michikazu
Vacuum and Surface Science, 62(7), p.400 - 405, 2019/07
no abstracts in English
Fukaya, Yuki; Matsuda, Iwao*; Fukutani, Katsuyuki
no journal, ,
no abstracts in English
2Yano, Masahiro; Terasawa, Tomoo; Yasuda, Satoshi; Machida, Shinichi*; Asaoka, Hidehito
no journal, ,
no abstracts in English
Hasegawa, Yuri; Honda, Mitsunori; Suzuki, Shinichi; Yaita, Tsuyoshi
no journal, ,
Recycling of radioactive polluted soil has been one the latest issues in environmental restoration. Among minerals in soil, weathered biotite fix Cs strongly. Recently, elimination of Cs accompanied by growth of various kind of crystal from weathered biotite was realized only by heating with alkali salt (NaCl-CaCl
). Since some of those crystals are available as a functional material, further understanding of the process of crystal growth is required for selective growth. However, understating the crystal growth is difficult because WB consists of weathered and un-weathered phase. Therefore, in this study, crystal growth form un-weathered biotite was investigated. XRD measurement revealed growth of FeO
, Wadalite, and pyroxene were observed from 2 
m of biotite, whereas pyroxene was not observed from 75m of biotite. In addition, pyroxene was not observed even with 2m of biotite when NaCl:CaCl=7:3. These result suggest size of biotite and NaCl:CaCl ratio affect selective growth.
Terasawa, Tomoo; Obata, Seiji*; Yasuda, Satoshi; Saiki, Koichiro*; Asaoka, Hidehito
no journal, ,
no abstracts in English
