The independence of the trapping of mobile particles near a solid surface on depth variation of diffusion

Following the discovery that when low energy He+ ions are injected into solids they can diffuse interstitially and potentially become trapped at lattice defects or impurity sites, the process has become widely used to determine the nature of such trapping sites. In this technique the He is injected and decorates the trapping sites and is then evolved from the solid by heating. Elegant mathematical analysis of the thermal evolution process has demonstrated how detailed experimental studies of evolution rate can be used to determine the important parameters of different types of trapping site. (author)