Thermal and fluid analysis for the IFMIF lithium target jet flow

The International Fusion Material Irradiation Facility (IFMIF) will generate 14 MeV neutrons in a high-velocity free-surface lithium (Li) jet target flowing on a concave wall in vacuum. The target jet receives the intense deuteron beam power, but should be avoided to cause voiding in the jet and significant vaporization at the jet free surface. The two-dimensional thermal and fluid analyses were thus performed to evaluate the temperature distribution and flow conditions which will be influenced by the back-wall geometry and jet average velocity. The calculated temperature distribution indicated an enough margin to avoid the voiding and vaporization for the various combinations of the back-wall radii and jet average velocities. The influence of the boundary layer onto the jet thickness was also studied. (author)