Upgrading of JRR-3/JRR-4 neutron beam utilities; For cold neutron beam and BNCT

Yamamoto, Kazuyoshi ; Tamura, Itaru  ; Kumada, Hiroaki; Maruo, Takeshi

To response to their requests, we proposed two plans. One is the enhancement of cold neutron beam intensity for JRR-3 and the other one is the progress of Boron Neutron Capture Therapy (BNCT) for JRR-4. Improvements of the liquid hydrogen moderator and the neutron guide tubes are more effective and efficient to increase cold neutron beam intensity at JRR-3. It was recently evaluated that a neutron intensity on the new moderator increases twice the current intensity by fitting selection of material and shape for the new moderator vessel. It was also evaluated that the neutron transportation efficiency at the end of curved guide tube could be improved 5 times with 3Qc super-mirrors. Although BNCT in JRR-4 has been mainly applied to therapy against brain tumor so far, technical developments to expand its application to therapy against the other cancers such as lung cancer, head and neck cancer are carried out as the needs are increasing these days.