Spin-orbit-interaction activated interchannel coupling in dipole and quadrupole photoionization

The effect of spin-orbit interaction activated interchannel coupling in dipole and quadrupole photoionization of the 4p and 4d subshells of Xe and the 5p and 5d subshells of Rn using the relativistic random phase approximation (RRPA) is studied. Interference between channels arising from spin-orbit split components is found to influence the dipole cross sections of Xe4d and Rn5d subshells, and also the quadrupole cross sections of Xe4p and Rn5p subshells. The photoelectron angular distribution parameters are also affected, but to a lesser extent. Using the understanding gained, the conditions required for large spin-orbit interaction activated interchannel coupling effects are delineated.