The influence of non-dipolar transitions on the angular photoelectron distribution

The relativistic calculations of non-dipolar angular parameters delta and g amma as well of dipole parameter beta for all shells of atoms from Li to Ar are performed. The photoelectron kinetic energy is taken in the range from 100 to 5000 eV. The trends of calculated values are discussed. The theoret ical values are compared with existing experimental data. It is shown that the non-dipolar transitions have a strong influence on the photoelectron an gular distribution and can lead to an extremum, which is absent in dipole a pproximation. (C) 2000 Elsevier Science B.V. All rights reserved.