Implementation of a low-activation Au-In-Cd decoupler into the J-PARC 1 MW short pulsed spallation neutron source

Teshigawara, Makoto; Ikeda, Yujiro; Oi, Motoki; Harada, Masahide; Takada, Hiroshi; Kakishiro, Masanori*; Noguchi, Gaku*; Shimada, Tsubasa*; Seita, Kyoichi*; Murashima, Daisuke*; et al.

Nuclear Materials and Energy (Internet), 14, p.14 - 21, 2018/01

https://doi.org/10.1016/j.nme.2018.02.001

We developed an Au-In-Cd (AuIC) decoupler material to reduce induced radioactivity instead of Ag-In-Cd one, which has a cut off energy of 1eV. In order to implement it into an actual moderator-reflector assembly, a number of critical engineering issues need to be resolved with regard to large-sized bonding between AuIC and A5083 alloys by the hot isostatic pressing process. We investigated this process in terms of the surface conditions, sizes, and heat capacities of large AuIC alloys. We also show a successful implementation of an AuIC decoupler into a reflector assembly, resulting in a remarkable reduction of radioactivity by AuIC compared to AIC without sacrificing neutronic performance.

Design of beam incident monitor for spallation neutron target of JSNS

Meigo, Shinichiro; Harada, Masahide; Teraoku, Takuji*; Maekawa, Fujio

Proceedings of ICANS-XVI, Volume 3, p.1175 - 1180, 2003/07

It is important to monitor the proton beam for the high intensity pulse spallation target. Especially for the beam halo, which may irradiate the bulk surrounding the target, it is important to be observed to prevent causing heat spot in the shielding bulk. At JSNS, a proton beam monitors are located at front of the target. These monitors are assembled with the proton beam window. Since this scheme increases the radiation on the monitor due to the beam loss at the windows, it may arise heat deposition on the monitor. Therefore, heat deposition is calculated with NMTC/JAM. It is found that the heat deposition for normal operation is less than 0.1 W/cc.

Structual design study of a proton beam window for a 1-MW spallation neutron source

Teraoku, Takuji*; Terada, Atsuhiko*; Maekawa, Fujio; Meigo, Shinichiro; Kaminaga, Masanori; Ishikura, Shuichi*; Hino, Ryutaro

JAERI-Tech 2003-026, 77 Pages, 2003/03

JAERI-Tech-2003-026.pdf:19.78MB

A 1-MW spallation neutron source aiming at materials and life science researches will be constructed under the JAERI-KEK Proton Accelerator Project(J-PARC). The proton beam window functions as a boundary wall between a high vacuum area and a helium atmosphere and it is cooled by light water because high heat-density is generated in the window material by interactions with the proton beam. Then, uniformity of the water flow is requested at the window to suppress a hot-spot that causes excessive thermal stress and cooling water boiling. Also, the window has to be strong enough in its structure for inner stress due to water pressure and thermal stress due to heat generation. In this report, we propose two types of proton beam windows, flat-type and curved-type. We evaluated the strength of structure and thermal hydraulic analysis. As a result, it was found that sufficient heat removal was assured with uniform water flow at the window, and the stress could be maintained below allowable stress values. Accordingly, it was confirmed that the proton beam window designs were feasible.