Fabrication of mercury target vessel

Wakui, Takashi; Kogawa, Hiroyuki; Haga, Katsuhiro; Futakawa, Masatoshi; Hayashi, Ryoichi*; Uchiyama, Naoyoshi*; Okamoto, Yoshinao*; Nakamura, Koji*

JAEA-Technology 2009-040, 96 Pages, 2010/03

JAEA-Technology-2009-040.pdf:35.52MB

The construction of materials and life science experimental facility in J-PARC project had been completed. The mercury target vessel consists of triple-walled structure in order to prevent the leak of mercury to outside at the failure of the mercury vessel and to remove the heat of the safety hull, which covers the mercury vessel, due to the injection of the pulsed proton beams. The high fabrication accuracy is required for the mercury target vessel assembled by the welding. In this report, the required specification and basic structure of parts in the mercury target vessel are described and the fabrication procedure of the mercury target vessel by the vender is reported. In the fabrication of the mercury target vessel, there were many troubles such as large deformation due to the welding and then the vender repaired and brought the mercury target vessel to completion. Furthermore, improvements for the design and fabrication of the mercury target are reported.

Present status of JSNS mercury target

Haga, Katsuhiro; Kogawa, Hiroyuki; Wakui, Takashi; Okamoto, Yoshihisa; Futakawa, Masatoshi; Kaminaga, Masanori; Kato, Takashi

Proceedings of 18th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-18) (CD-ROM), 14 Pages, 2007/00

The construction of the 1MW class mercury target which is the world highest level as the spallation neutron source is going on under the J-PARC project. The mercury target system consists of the mercury target vessel, the mercury circulation system and the target trolley. The outline of the mercury target system and several topics appeared in the course of the system fabrication and assembling are reported. For the target vessel, the residual stress at the beam window was evaluated and it was confirmed that the stress level is low and no problem. For the mercury pump, the mechanical EM pump which is free of mercury leak was developed and we could get prospect that the pump can be used under the beam condition of up to 400kW. For the target trolley, we confirmed that the very heavy body which is nearly 300t can be positioned with the accuracy of 1mm which is required for the system operation.