Near-threshold study of Xe 3d photoionization

The 3d photoelectron spectrum of xenon has been measured at several photon energies in the immediate threshold region. The absolute photoionization cross section and angular anisotropy parameter ? have been determined for the two spin-orbit-split components. The experimental results are compared with calculations using a relaxed single-channel approximation. In agreement with theory, most abrupt changes in cross section and angular distribution are observed just above threshold. However, the Xe 3d5/2 photoionization cross section also reveals, some 30-eV above threshold a second maximum that has not been predicted theoretically.