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Naoe, Takashi; Wakui, Takashi; Kinoshita, Hidetaka; Kogawa, Hiroyuki; Teshigawara, Makoto; Haga, Katsuhiro
JAEA-Technology 2023-022, 81 Pages, 2024/01
In the liquid mercury target system for the pulsed spallation neutron source of Materials and Life Science Experimental Facility (MLF) in the Japan Proton Accelerator Research Complex (J-PARC), pressure waves that is generated by the high-energy proton beam injection simultaneously with the spallation reaction, resulting severe cavitation erosion damage on the interior surface of the mercury target vessel. Because the bubble of pressure wave-induced cavitation collapsing near the interior surface of the mercury target vessel with applying the large amplitude of localized impact on the surface. Since the wall thickness of the beam entrance portion of the target vessel is designed to be 3 mm to reduce thermal stress due to the internal heating, the erosion damage has the possibility to cause the vessel fatigue failure and mercury leakage originated from erosion pits during operation. To reduce the erosion damage by cavitation, a technique of gas microbubble injection into the mercury for pressure wave mitigation, and double-walled structure of the beam window of the target vessel has been applied. A specimen was cut from the beam window of the used mercury target vessel in order to investigate the effect of the damage mitigation technologies on the vessel, and to reflect the consideration of operation condition for the next target. We have observed cavitation damage on interior surface of the used mercury target vessel by cutting out the disk shape specimens. Damage morphology and depth of damaged surface were evaluated and correlation between the damage depth and operational condition was examined. The result showed that the erosion damage by cavitation is extremely reduced by injecting gas microbubbles and the damage not formed inside narrow channel of the double-walled structure for relatively high-power operated target vessels.
Takase, Kazuyuki; Ose, Yasuo*; Yoshida, Hiroyuki; Akimoto, Hajime; Satake, Shinichi*
Proceedings of International Conference on Jets, Wakes and Separated Flows (ICJWSF 2005), p.137 - 144, 2005/11
no abstracts in English
Kume, Etsuo; Kitamura, Tatsuaki*; Takase, Kazuyuki; Ose, Yasuo*
Kashika Joho Gakkai-Shi, 25(Suppl.2), p.369 - 370, 2005/10
no abstracts in English
Takase, Kazuyuki; Ose, Yasuo*; Yoshida, Hiroyuki; Akimoto, Hajime; Aoki, Takayuki*
Dai-24-Kai Nihon Shimyureshon Gakkai Taikai Happyo Rombunshu, p.161 - 164, 2005/07
no abstracts in English
Takase, Kazuyuki; Yoshida, Hiroyuki; Ose, Yasuo*
Proceedings of 1st International Forum on Heat Transfer (IFHT 2004), p.207 - 208, 2004/11
no abstracts in English
Takase, Kazuyuki; Yoshida, Hiroyuki; Ose, Yasuo*; Tamai, Hidesada; Akimoto, Hajime
Transactions of the American Nuclear Society, 89, p.88 - 89, 2003/11
no abstracts in English
Takase, Kazuyuki; Yoshida, Hiroyuki; Ose, Yasuo*
Nihon Kikai Gakkai 2003-Nendo Nenji Taikai Koen Rombunshu, Vol.6, p.205 - 206, 2003/00
no abstracts in English
Takase, Kazuyuki; Yoshida, Hiroyuki; Ose, Yasuo*; Tamai, Hidesada; Akimoto, Hajime
Proceedings of International Conference on Supercomputing in Nuclear Applications (SNA 2003) (CD-ROM), 15 Pages, 2003/00
no abstracts in English
Kureta, Masatoshi; Akimoto, Hajime
International Journal of Heat and Mass Transfer, 45(20), p.4107 - 4115, 2002/09
Times Cited Count:44 Percentile:80.74(Thermodynamics)no abstracts in English
Takase, Kazuyuki; Ose, Yasuo*; Yoshida, Hiroyuki; Tamai, Hidesada; Kume, Etsuo; Kitamura, Tatsuaki*
Dai-16-Kai Suchi Ryutai Rikigaku Shimpojiumu Koen Yoshishu, 7 Pages, 2002/00
no abstracts in English
Kinoshita, Hidetaka; Terada, Atsuhiko*; Kaminaga, Masanori; Hino, Ryutaro
JAERI-Tech 2001-061, 43 Pages, 2001/10
no abstracts in English
; ; Kaminaga, Masanori; Hino, Ryutaro; Sudo, Yukio
JAERI-Tech 99-019, 22 Pages, 1999/02
no abstracts in English
M.S.Islam*; Hino, Ryutaro; Haga, Katsuhiro; Monde, Masanori*; Sudo, Yukio
JAERI-Tech 97-032, 49 Pages, 1997/07
no abstracts in English
M.S.Islam*; Hino, Ryutaro; Haga, Katsuhiro; Monde, Masanori*; Sudo, Yukio
JAERI-Tech 97-008, 46 Pages, 1997/03
no abstracts in English
Kawamura, Shunsuke; Naoe, Takashi; Ikeda, Tsubasa; Tanaka, Nobuatsu*; Futakawa, Masatoshi
no journal, ,
A target vessel enclosing mercury made of stainless steel is used for the J-PARC spallation neutron source. It is severely damaged by the pressure-wave-induced cavitation with injecting intense proton beam. The front end of the target vessel has a double-walled structure with a narrow channel was adopted to the vessel for expecting to reduce cavitation damage. Effect of cavitation damage mitigation in narrow channel has been experimentally demonstrated. However, damage mitigation mechanism is not clarified yet. As a first step of studies to understand the mechanism of cavitation damage mitigation in narrow channel, growth and collapse behaviors of the spark-induced cavitation bubbles under flow condition were observed by using a high-speed video camera. Furthermore, the wall vibration by cavitation bubble collapse was measured by parametrically changing the flow velocity. The experimental results showed that the ejection angle of the microjet ejected by bubble collapsing leaned towards flowing direction as the flow velocity increases. The wall vibration was reduced with increasing flow velocity.