Measurement of energetic charged particles produced in fusion materials with 14 MeV neutron irradiation

For the evaluation of the damages, nuclear heating, and also tritium inventory in the fusion materials, the precise information of the energetic charged particles produced in the materials by nuclear reactions is important. Fusion neutronics source in Japan Atomic Engineering research Association, JAERI/FNS, has started the measurements of the double differential cross-sections (DDXs) and the angular differential cross-sections (ADXs) for the candidate materials of fusion reactors using the collimated D–T neutron beam system and the precise results of the DDXs and ADXs for the 9Be(n,αx) and 9Be(n,t) reactions have been obtained. Also, from the comparison of the evaluated nuclear data for the beryllium, it was found that the calculated DDX of 9Be(n,α) above about 3 MeV was underestimated and the total 9Be(n,t) cross-section obtained with the measurement of the DDX and ADX was in good agreement with the evaluated nuclear data. In the following sections, the details of the measurement methods for the charged particles and the obtained DDX and ADX for the beryllium are described.