Temperature dependence of liquid-lithium sputtering from oblique 700 eV He ions

The lithium-sputtering yield of liquid lithium as a function of sample temperature has been measured in the ion-surface interaction experiment (IIAX). Lithium sputtering is measured for D⁺, He⁺ and Li⁺ bombardment at energies between 100 and 1000 eV at 45° incidence. In this work VFTRIM-3D is used to provide a qualitative physical picture of mechanisms responsible for the temperature dependence of liquid-lithium sputtering. The present study is done for 700 eV He⁺ bombardment of liquid lithium at 45° incidence with respect to the target normal. The lithium-sputtering yield, after evaporation is taken into account, is found to increase almost an order of magnitude when the target temperature is increased from the melting point up to roughly 410 °C. The deposited energy distribution near the liquid-lithium surface is found to play a significant role in explaining the observed enhanced lithium sputtering as well as the temperature dependence of the surface binding energy.