Mesh size effects in alpha-particle backscattering

Alpha-particle backscattering is a familiar technique for determining the elemental composition of surfaces. In the present work, the effect of the surface structure of the sample is investigated. It is found that the spectrum of the backscattered α particles depends on the surface structure; hence, the ability to resolve different nuclear species in the sample by this method depends on the nature of the surface. If the linear dimension of the surface structure is of the same order of magnitude as the α-particle range in the material, a significant change in the spectrum of backscattered α particles is observed. For surface structures much larger or much smaller than the α-particle range, normal spectrums are observed.