Implementation of a collimated DT neutron beam at the 1st target room of JAEA/FNS for new integral benchmark experiments

Onishi, Seiki; Kondo, Keitaro; Sato, Satoshi; Ochiai, Kentaro; Takakura, Kosuke; Konno, Chikara  ; Murata, Isao*

So far we carried out many integral benchmark experiments (in-situ experiments and Time-Of-Flight experiments) for nuclear data with DT neutrons at the Fusion Neutronics Source facility in Japan Atomic Energy Agency. In addition to those, we have a plan to perform new integral benchmark experiments for nuclear data with a DT neutron beam, which can investigate nuclear data for almost the whole angle and the whole energy. Because the large-size tritium target in FNS is difficult to procure, we have started to build a new DT neutron beam with the small tritium target, which is easy to obtain, at the first target room of FNS. We already designed a collimator system for the DT neutron beam based on calculations. In this work, under that design, the collimator was constructed. Then the characteristics of the neutron field were measured in order to confirm the DT neutron beam performance. It was demonstrated that the DT neutron beam was realized as calculated.