Abstract
Desorption spectra of various doses of 160eV helium ions injected into a damaged polycrystallinc tungsten target are described. Conclusions derived from these are applied to the interpretation of spectra obtained for the injection of helium (at different energies and doses) into an undamaged target, and are shown to be consistent with the spectral variations observed. Experiments are described in which a damaged target was partially annealed prior to the injection of 160 eV helium, with the result that the desorption spectra were modified in such a way as to reveal new information about certain trapping sites and release processes in tungsten.