Channeling of MeV He + Ions in Tungsten and Other Crystals: An Intercomparison of Rutherford Scattering and of Characteristic L and M X-Ray Yields

摘要: Measurements of wide-angle (150\ifmmode^\circ\else\textdegree\fi{}) scattering and $L$ $M$ x-ray yields in tungsten single crystals are reported as a function crystallographic orientation with respect to an incident beam 1.4-MeV helium ions. Comparison these establishes both lower upper limits for the minimum impact parameter (${r}_{min}$) between channeled ion tungsten-lattice atoms; consistent Lindhard's estimate that ${r}_{min}\ensuremath{\sim}\mathrm{a}$, Thomas-Fermi screening distance (i.e.,\ensuremath{\sim}0.11 \AA{} He W). A similar comparison yield curves is several other lattices\char22{}Al, Si, GaP, GaSb, U${\mathrm{O}}_{2}$; again results predicted relationship: ${r}_{min}\ensuremath{\sim}\mathrm{a}$. Anomalies published studies $K$, $L$, shown be due depth effects.