TRANSPORT MODEL OF THERMAL AND EPITHERMAL POSITRONS IN SOLIDS .1.

Epithermal positron transport in solids is treated by employing a one-dimensional Boltzmann equation, which, in combination with the diffusion equation for the thermalized positrons, gives rise to a more realistic model for transport of positrons implanted into solids with variable energies. Thermalization is accounted for by the averaged inelastic scattering of the epithermal positrons, although the epithermal positron energy distribution cannot be predicted from this model. © 1990 The American Physical Society.