
%0 Journal Article
%A Price, PB 
%A Kelly, JC 
%T Channelling of MeV H and He Ions in Alkali Halides at 'Zero Dose' Measurements
%J Australian Journal of Physics
%D 1977/12/01
%V 30
%N 6
%P 617-630
%K 
%R https://doi.org/10.1071/PH770617
%U https://www.publish.csiro.au/paper/PH770617 
%X Measurements of the minimum scattering yield Xmln and the half-angle for channelling 1fI~ have been made for crystals of LiF, NaF, NaC! and KCI at very small total doses of H+ and 4He+ ions. The measured values of 1fI~ are in good agreement with theory. Comparison of the results for Xmln as a function of depth, with theories based on a linear increase of the mean square beam divergence Q2, shows that for the alkali halides studied the initial beam divergence Q o on entering the crystal is proportional to 1f11> the Lindhard characteristic channelling angle. 
