First experimental determinations and R-matrix calculations of the angular distribution of photoelectrons ejected in direct inner-shell photoionization of excited atoms.
Measurements of the angular distribution of 2{ital p} photoelectrons ejected from the 2{ital p}{sup 6}3{ital p}{sup 2}{ital P}{sub 3/2} state of excited sodium atoms have been performed over a broad photon energy range (50--140 eV) using synchrotron radiation. The outgoing photoelectrons were detected with a new multichannel system. The angular distribution of these electrons was also calculated in the {ital R}-matrix approximation. Our theoretical results for the partial photoionization cross sections and the angular distribution parameter are in excellent agreement with all experimental observations reported here and in earlier works.