Development of beryllium-based neutron target system with three-layer structure for accelerator-based neutron source for boron neutron capture therapy

The iBNCT project team with University of Tsukuba is developing an accelerator-based neutron source. Regarding neutron target material, our project has applied beryllium. To deal with large heat load and blistering of the target system, we developed a three-layer structure for the target system that includes a blistering mitigation material between the beryllium used as the neutron generator and the copper heat sink. The three materials were bonded through diffusion bonding using a hot isostatic pressing method. Based on several verifications, our project chose palladium as the intermediate layer. A prototype of the neutron target system was produced. We will verify that sufficient neutrons for BNCT treatment are generated by the device in the near future. •Beryllium is applied to neutron target material for accelerator based neutron source.•Three-layer structure for the beryllium-based target system was developed.•Regarding intermediate material, hydrogen-storing material is used to suppress blistering.•The three materials are bonded through diffusion bonding using a hot isostatic pressing method.•Palladium is applied as the intermediate material of the target system.•Prototype of the three-layer structure target system was installed in accelerator based neutron source for BNCT device.