Ion-reversibility studies in amorphous solids using the two-atom scattering model. [Rutherford backscattering from disordered solids]
An analytical two-atom scattering model has been developed to treat the recent discovery of the enhancement near 180/sup 0/ of Rutherford backscattering yields from disordered solids. In contrast to conventional calculations of Rutherford backscattering that treat scattering from a single atom only (the backscattering atom), the present model includes the interaction of a second atom lying between the target surface and the backscattering plane. The projectile ion makes a glancing collision with this second atom both before and after it is backscattered. The model predicts an enhancement effect whose physical origin arises from the tolerance of path for those ions whose inward and outward trajectories lie in the vicinity of the critical impact parameter. Results using Moliere scattering show how the yield enhancement depends on ion energy, backscattering depth, exit angle, scattering potential, atomic numbers of the projectile and target, and target density. In the model the critical impact parameter and critical angle play important roles. It is shown that these quantities depend on a single dimensionless parameter and analytical expressions for them are given which are accurate to better than 1%.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 6315673
- Report Number(s):
- CONF-810732-1; ON: DE81025188; TRN: 81-014398
- Resource Relation:
- Conference: Seminar on recent theoretical (computational) developments in atomic collisions in soilds, Strasbourg, France, 14 Jul 1981
- Country of Publication:
- United States
- Language:
- English
Similar Records
Two-atom model in enhanced ion backscattering near 180/sup 0/ scattering angles
Experimental findings in 180{degree} backscattering enhancement from solids