Chapter 1 - Introduction

Abstract

This chapter discusses about relativistic atomic collision. A relativistic atomic collision is one in which an ion or atom impinges on an atomic system with a velocity that is comparable to the speed of light. It is assumed that during the entire collision the distance between the two nuclei involved remains large enough, so that only electromagnetic interactions prevail and strong interactions do not play any role. In principle, all particles involved ‑ electrons and nuclei ‑ must be described theoretically by quantum mechanics. In the wave picture, the nuclear motion is described by solving the stationary wave equation for a fixed energy. In this description, the incoming and outgoing waves for the relative nuclear motion extend over all space and are characterized by their asymptotic momenta. Nonrelativistic collisions span a wide energy range, starting with chemical reactions at thermal energies and reaching to tens of MeV/u in accelerator-produced collisions. The parametric dependencies of the cross sections are also elaborated.