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Kawamura, Seiko; Takahashi, Ryuta*; Ishikado, Motoyuki*; Yamauchi, Yasuhiro*; Nakamura, Masatoshi*; Ouchi, Keiichi*; Kira, Hiroshi*; Kambara, Wataru*; Aoyama, Kazuhiro*; Sakaguchi, Yoshifumi*; et al.
Journal of Neutron Research, 21(1-2), p.17 - 22, 2019/05
The Cryogenics and Magnets group in the Sample Environment team is responsible for operation of cryostats and magnets for user's experiments at the MLF in J-PARC. We have introduced a top-loading He cryostat, a bottom-loading He cryostat, a dilution refrigerator insert and a superconducting magnet. The frequency of use of them dramatically becomes higher in these two years, as the beam power and the number of proposal increase. To respond such situation, we have made efforts to enhance performance of these equipment as follows. The He cryostat originally involves an operation software for automatic initial cooling down to the base temperature and automatic re-charge of He. Recently we made an additional program for automatic temperature control with only the sorb heater. Last year, a new outer vacuum chamber of the magnet with an oscillating radial collimator (ORC) was fabricated. The data quality was drastically improved by introducing this ORC so that the magnet can be used even for the inelastic neutron scattering experiments.
Kajita, Shin; Ono, Noriyasu*; Takamura, Shuichi*; Sakaguchi, Wataru*; Nishijima, Dai*
Applied Physics Letters, 91(26), p.261501_1 - 261501_3, 2007/12
Times Cited Count:41 Percentile:79.61(Physics, Applied)Nanosecond laser ablation of tungsten (W) that was exposed to helium plasmas was investigated using optical emission spectroscopy. Sub-micrometor holes/bubbles are formed on the surface of W specimen when it was exposed to the helium plasma at sufficient higher temperature ( 1500-1600 K). The onset pulse energy to detect W I becomes 0.2 J/cm after the W specimen was exposed to high-density helium plasmas, though the emission from a pure virgin W (before helium plasma irradiation) cannot be detected when the pulse energy was lower than 1 J/cm. Laser-induced bursting of the holes/bubbles is suggested to be the physical mechanism leading to the significant reduction in the ablation power threshold.
Ito, Takashi; Higemoto, Wataru; Koda, Akihiro*; Shimomura, Koichiro*; Nishiyama, Kusuo*; Matsuzaki, Teiichiro*; Tomono, Dai*; Kobayashi, Yoji*; Sakaguchi, Tatsunori*; Kageyama, Hiroshi*
no journal, ,
no abstracts in English
Ito, Takashi; Higemoto, Wataru; Koda, Akihiro*; Shimomura, Koichiro*; Nishiyama, Kusuo*; Matsuzaki, Teiichiro*; Tomono, Dai*; Kobayashi, Yoji*; Sakaguchi, Tatsunori*; Kageyama, Hiroshi*
no journal, ,
no abstracts in English
Aso, Tomokazu; Yamauchi, Yasuhiro; Sakaguchi, Yoshifumi*; Munakata, Koji*; Ishikado, Motoyuki*; Kawamura, Seiko; Yokoo, Tetsuya*; Watanabe, Masao; Takata, Shinichi; Hattori, Takanori; et al.
no journal, ,
In FY2013, the SE team was officially organized in Technology Development Section in MLF with succeeding the previous ad hoc SE team. We are working on operation of so-called beam-line (BL)-common SE equipment and development of the SE devices as well as the previous SE team. We have already prepared a vertical-field superconducting magnet, a dilution refrigerator insert, a furnace with Nb heater and 2K cryostat as the BL-common SE equipment. In this fiscal year, a bottom-loading type He cryostat will be introduced. Moreover, we have just started developing high pressure system by collaborating with High Pressure Group in MLF, to comply with users' requests. We have also discussed the general purpose of apparatus for pulse magnet and for hydrogen environment. We plan to prepare more working area for the SE equipment, whose number gradually increases, and sample preparation and characterization rooms for users in the new building, which is under construction.
Yamauchi, Yasuhiro; Sakaguchi, Yoshifumi*; Munakata, Koji*; Ishikado, Motoyuki*; Kambara, Wataru; Kawamura, Seiko; Yokoo, Tetsuya*; Aso, Tomokazu; Aizawa, Kazuya
no journal, ,
In April 2013, Technology Development Section was newly established in Materials and Life Science Division, J-PARC Center to promote user support, maintenance and development of common devices. Simultaneously, the official sample environment (SE) group was organized in this section, and then some staff members from CROSS also joined this group. We have supported operation of beamline (BL)-common SE equipment at various BL's and have modified them partly to improve the safety and usability in operation. In addition to them, we have carried out operation and maintenance of some pieces of equipment dedicated to BL's, in order to enhance specialized skills and experience. Utilities of the SE working area have been equipped almost completely, and then the working circumstances have been gradually improved.
Aso, Tomokazu; Yamauchi, Yasuhiro; Sakaguchi, Yoshifumi*; Munakata, Koji*; Ishikado, Motoyuki*; Kawamura, Seiko; Yokoo, Tetsuya*; Watanabe, Masao; Takata, Shinichi; Hattori, Takanori; et al.
no journal, ,
In FY2013, the SE team was officially organized in Technology Development Section in MLF with succeeding the previous ad hoc SE team. We are working on operation of so-called beam-line (BL)-common SE equipment and development of the SE devices as well as the previous SE team. We have already prepared a vertical-field superconducting magnet, a dilution refrigerator insert, a furnace with Nb heater and 2K cryostat as the BL-common SE equipment. In this fiscal year, a bottom-loading type He cryostat will be introduced. Moreover, we have just started developing high pressure system by collaborating with High Pressure Group in MLF, to comply with users' requests. We have also discussed the general purpose of apparatus for pulse magnet and for hydrogen environment. We plan to prepare more working area for the SE equipment, whose number gradually increases, and sample preparation and characterization rooms for users in the new building, which is under construction.