Target cooling options for DARIA compact neutron source

Abstract

The extensive heat release in the target is the primary limiting factor for a CANS neutron output. CANS DARIA has been chosen to operate using a 13 MeV proton beam providing up to 40 kW of power, which requires an effective target cooling solution. It was found that beryllium provides the best neutron yield while staying in solid state, which makes it the most effective option for the target material. With an optimal beryllium target thickness of 1.1 mm, the proton Bragg peak lies outside of the beryllium layer, but 9.21 MeV per incident proton are still dissipated inside the beryllium. Two cooling options are considered and analysed with PHITS calculations: multilayer targets and rotating targets. The use of proton beams with energies above 13 MeV on beryllium leads to tritium generation, which is not desirable. Any lower energy leads to a decreased neutron yield, but a simpler cooling solution. Therefore, an option to reduce the proton beam energy is also considered.