Nondipolar photoelectron angular distributions

Abstract

Abstract. The deviations of photoelectron angular distributions from the simple, highly symmetric shapes predicted within the electric-dipole approximation are investigated. The admixture of an electric-quadrupole component in the photon-atom interaction causes an asymmetry in the angular distribution with respect to the direction of photon propagation. The reported measurement of the angular distributions of argon Is, krypton 2s, and krypton 2 p photoemission within 2-3 keV above their respective thresholds reveal pronounced asymmetries which are present even at low electron kinetic energies. The measured asymmetry parameters are in good agreement with recent predictions from nonrelativistic calculations.