Liquid Lithium Target for High Energy Neutron Generation

Liquid lithium has gained increasing interest as a plasma facing component because of observed enhancement in plasma performance. Most notably, increases in temperature and core density. The Liquid Metal Infused Trench (LiMIT) concept, developed at the University of Illinois, has demonstrated successful performance under fusion relevant conditions in the EAST tokamak and in Magnum PSI with heat fluxes up to 8 MW/m² and 3 MW/m², respectively. Recently, this concept has been extended to create compact, self-flowing liquid lithium targets for beam-target fusion neutron generators, which can produce heat fluxes on the order of 10’s to 100’s of MW/m² due to their small spot size. The liquid lithium surface acts as a self-healing plasma facing material and allows for the production of fusion relevant neutron spectra without tritium for materials testing by utilizing the Li-7(d,n) and D(d,n) reactions. Initial experiments, where a temperature gradient was imposed only via cooling, peak velocities of 16 ± 4 cm/s were observed. Expected yields of this system are 10⁷ n/s for 13.5 MeV neutrons and 10⁸ n/s for 2.45 MeV neutrons. Neutron measurements have been made via a deuterated stilbene scintillator. Results involving the lithium flow and the neutron measurements will be presented.