A new irradiation method with a neutron filter for silicon neutron transmutation doping at the Japan research reactor no. 3 (JRR-3)

We studied a new silicon irradiation holder with a neutron filter designed to make the vertical neutron flux profile uniform. Since an irradiation holder has to be made of a low activation material, we applied aluminum blended with B4C as the holder material. Irradiation methods to achieve uniform flux with a filter are discussed using Monte-Carlo calculation code MVP. Validation of the use of the MVP code for the holder's analyses is also discussed via characteristic experiments.

► We studied a new silicon irradiation holder with a neutron filter made from B4C. ► Designs of the holder were investigated by using the MVP code. ► Calculation method was validated by characteristic experiments in the JRR-3. ► The vertical uniformity was ±3% when using the new type holder.