Regular and chaotic motion domains in the channeling electron's phase space and mean level density for its transverse motion energy

Abstract

The motion of charged particles in a crystal in the axial channeling regime can be both regular and chaotic. The chaos in quantum case manifests itself in the statistical properties of the energy levels set. These properties have been studied previously for the electrons channeling along direction of the silicon crystal, in the case when the classical motion was completely chaotic. It is demonstrated that the level spacing distribution for both electrons and positrons can be better described by Berry-Robnik distribution than by both Wigner (completely chaotic case) or Poisson (completely regular case) distributions