Channeling, Bremsstrahlung and Pair Creation in Single Crystals

Abstract

On the following pages, I shall describe various directional effects associated with the penetration of energetic charged particles through single crystals in directions close to low-index crystallographic directions, that is, close to low-index axes and planes. In particular, I shall focus on the special case of channeling: In channeling, the charged particles are so closely aligned with, say, an axis that their motion is completely governed by many correlated collisions with lattice atoms and their flux is prevented from being uniform in the space transverse to the considered crystal direction. In the interaction with a given atomic row or string, a projectile deflects as off a continuum string obtained by smearing the atomic charges uniformly along the string direction ($\overset{\wedge }{\mathop{z}}\,$). The interaction with the crystal is, in lowest approximation, through a z-independent continuum potential.