K-shell photoionizations in strongly coupled plasmas

Abstract

In strongly coupled plasmas, the photoionizations from the 1s ground state of hydrogenic ions are investigated using the ion-sphere model potential. The initial bound wave function and energy eigenvalue of the target ion are modified in the ion-sphere potential using the Ritz variation method. The final state of the ejected photoelectron is represented by a plane wave solution. The Coulomb correction is considered using the screened Coulomb wave function with the appropriate effective charge. The K-shell photoionization cross section is obtained for the acceleration form of the matrix element because of the convenience of the calculations. The plasma screening effect is obtained as a function of the ion-sphere radius and photon energy. The retardation correction is also considered in obtaining the total K-shell photoionization cross section in strongly coupled plasmas. The plasma screening effects on the total K-shell photoionization cross section for the ion-sphere radius, RZ⩾2aZ, are found to be less than about 25%. It is also found that the plasma screening effect is almost independent of the incident photon energy.