Present status of JSNS mercury target

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

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.