Ion beam analysis of Li-Sn alloys for fusion applications

Abstract

The use of liquid Li-Sn alloys for nuclear fusion applications may be hampered by the high melting point of Li-rich intermetallics. Aiming to inhibit their formation, the blend of pure Li (as high as 15 at.%) with pure Sn was controlled via mechanical alloying at room temperature under a dry Ar atmosphere. The depth profiling of Li down to depths near 15–20 μm was followed by nuclear reaction analysis, while elastic backscattering spectroscopy indicated the absence of O within the alloys. Elemental mapping using a nuclear microprobe evidenced the lateral spread of Li in the Sn matrix and identified Cr, Fe and Pb as the only contaminants with contents lower than 0.05 at.%. Despite the competing 2H(3He,p)4He, 6Li(3He,p)8Be, 7Li(3He,p)9Be and 7Li(3He,d)8Be nuclear reactions, retained amounts of deuterium in irradiated surfaces may be quantified with incident 3He+ ion beams in the 0.7 MeV–1.0 MeV energy range.