Shell Structure Potential for Channeling in Solids

Abstract

The position dependence of the stopping power in planar and axial channels using the shell model charge density is established. The corresponding shell atomic potential is derived from the shell charge density using Poisson's equation. By using the continuum model approximation, axial and planar potentials are calculated. A comparison with other frequently used statistical potentials established the possibility to apply this shell potential usefully and analytically to various problems of atomic collisions in solids.

Planar Channeling Radiation from Relativistic Electrons and Positrons in Silicon

“…The corresponding shell interatomic potential [12] has been derived and extended to both planar and axial cases. It was shown that the shell potential compares well with the other statistical-type potentials [9] in the channeling region (0.1 to 0.2 nm). This gave us the motivation to use this shell potential in channeling radiation studies.…”

“…We have successfully reproduced the z,-oscillations [2] in stopping power for silicon and tungsten for low velocity channeled heavy ions using the shell model charge density [8]. We have also calculated proton energy losses in the intermediate energy region (40 to 300 keV) and a-particle energy losses in the high energy region (0.15 to 18 MeV) in silicon single crystal using the shell model charge density [9] and found the results are in good agreement with experimental results [lo, 111. The corresponding shell interatomic potential [12] has been derived and extended to both planar and axial cases.…”

“…Using the continuum approximation [l] the shell planar potential is given by [9] where y is the distance measured from the plane, N the bulk density, d, the interplanar space. The above-mentioned shell planar potential is used for calculating transitional energies for planar channeled positrons and electrons.…”

Dechanneling of Positrons in Disordered Lattices – Effect of Anharmonic Potential

“…Here, the calculations have been extended up to the x 6 term. The dependence of the transmission and dechanneling coefficients on the incident beam position have been investigated by using a planar potential function based on the shell structure model [8] and compared with the results of the planar potential function based on Lindhard's model.…”