Date of Award
Doctor of Philosophy
This thesis contains the results of both experimental and theoretical studies of low-energy positron channeling in solids. The experimental work describes investigations of both axial and planar positron channeling in Si over a range of incident energies from 8 to 50 keV. Strong channeling effects are observed and these are examined with regard to the classical description as well as the expected onset of quantum-mechanical effects. To describe the latter, a full discussion of the quantum-mechanical channeling problem is given for the planar case. In this, we present an analytical model which we use to describe the role of positron energy band structure in channeling theory as well as to examine the convergence of various other techniques. For the general planar channeling problem, a new integral equation approach is presented. Comparisons between the latter and the more traditional Multiple-Beam method are given and good agreement is observed. It is found that, at least in some cases, the new integral technique offers strong computational advantages.
Logan, Lyndon Ronald, "Low-energy Positron Channeling" (1990). Digitized Theses. 1890.