ANALYSIS OF BEAM-ON-TARGET INTERACTION IN A NEUTRON-SOURCE TEST FACILITY

The need is urgent for a high-flux, high-energy neutron test facility to evaluate the performance of fusion reactor materials. An accelerator-based deuterium-lithium source is generally considered the most reasonable approach to a high-flux neutron source in the near future. The idea is to bombard a high-energy (20-40 MeV) deuteron beam into a lithium jet target to produce high-energy neutrons in order to simulate a fusion reactor environment via the Li (d, n) nuclear stripping reaction. Deposition of the high-energy deuteron beam and the subsequent response of the lithium jet are modeled and evaluated in detail. To assess the feasibility of this concept, the analysis is done parametrically for various deuteron beam energies, beam currents, and jet velocities. A main requirement for a successful operation is to keep the free jet surface at a minimum temperature to reduce surface evaporation of lithium into the vacuum system. The effects of neutron-generated heating and irradiation on the jet-supporting back plate are also evaluated. The back plate must maintain a reasonable lifetime during system operation.