Sputtering of uranium

A fission track technique was employed to study the sputtering of uranium by ^1H^+, ^4He^+, and ^(40)Ar^+ ions with energies up to 120 keV. The technique involves detection of fission tracks produced in mica by ^(235)U sputtered onto collector foils which are subsequently irradiated with thermal neutrons. This method is extremely sensitive and allowed measurement of sputtering yields less than 10^(−4) atoms per ion. It also made possible a detailed study of the emission of chunks from the uranium targets during sputtering. Mass distributions of chunks emitted during bombardment by 40-120 keV protons and by 80 keV argon are presented. Angular distributions of sputtered material and total sputtering yields for uranium metal under bombardment by 13-120 keV protons and by 40-120 keV ^4He^+ are also presented. Sputtering yields for 40 and 80 keV ^(40)Ar^+ were measured as well. Comparisons are made between the experimental results and those predicted by the collision cascade model