Angle-resolved energy dependence of the 4p⁴nd(²S_1/2) (n=4–7) correlation satellites in Kr from 38.5 to 250 eV: Experiment and theory

We measured and calculated the energy dependence of the 4p⁴nd(²S_1/2) (n=4–7) correlation satellites in Kr from 38.5 to 250 eV. Our high-resolution measurements used a photoelectron spectroscopy technique to determine the relative cross sections and angular distribution parameters β. We find that, as in the case of Xe, the absolute cross sections of these satellites lines follow very closely the shifted and scaled cross section of the 4s main line. However, in the case of β, we find that the nd(²S_1/2) (n=4,5,6) follow the β value of the 4s main line below 150 eV only, and that β of the 7d(²S_1/2) satellite does not. We find that the β of the nd(²S_1/2) (n=4, 5, and 6) satellites reach β=2 below 150 eV, but this value drops significantly between photon energies of 200 and 250 eV. While the comparison of our measurements with our calculation is good overall, some effects are not reproduced by the calculation. Our results are compared with a previous measurement at 68.5 eV, and the agreement is fair. We also measured the 4s and 4p main line cross sections and angular distributions and these results are compared to previous measurements and calculations.