Positron Annihilation: Experiment and Theory

The following sections are included:

• Background

• Interaction of Positrons with Vacancies in Metals

• Trapping Model

  • Positron-Diffusion Mechanism and Enthalpy of Formation of Monovacancies

  • Trapping Rate

• Positron-Annihilation Characteristics

  • Vacancies and Vacancy Clusters

  • Dislocations

  • Grain Boundaries and Interfaces

  • Voids and Cracks

• Electron and Positron Momentum Distributions in Solids

  • Introduction

  • Positron Implantation and Thermalization

  • Positron Diffusion

  • Positron Distribution in Solids

  • Electron-Positron Correlation in Pure Metals and the Core Effects

  • Momentum Density in Crystalline Solids

  • 1D and 2D ACAR Measurements

  • Examples of Momentum Density Calculations and Experiments

• Experimentation with Low-Energy Positron Beams

  • Positron Diffusing Back to Metal Surface

  • Positron Trapping at Monovacancies Near a Surface

  • Defect Profiling with Positron-Beams

• Summary