Table 1.

Scattering process dependence on adlayer material as obtained by SRIM. For each adlayer/sample combination the number of backscattered helium atoms and the longitudinal and radial ion ranges (in Å) are given. 1 × 10⁵ He ions with a PE of 35 keV under normal incidence were used in the calculation.

sample	BSHe	direction	range [Å]	straggle [Å]
Pb/Si	1863	long.	3095	952
		rad.	1567	782
Li/Si	881	long.	3261	918
		rad.	1443	712
Si	979	long.	3190	917
		rad.	1446	714