Differential cross section ratios for low-energy electron-impact excitation of the levels of krypton - sensitive tests of relativistic effects for heavy noble gases

Abstract

We present new experimental measurements and theoretical calculations of R-matrix and unitarized first-order many-body theory for electron-impact excitation of krypton. The usefulness of differential cross section ratios in providing sensitive tests of electron scattering models for the excitation of the configuration of the heavy rare gases is demonstrated. In addition to differential cross sections alone, these ratios provide interesting physical insights into the details of the collision process. Comparisons of the measured ratios with predictions from the present and other available calculations show some agreement, but also reveal that significant improvements of these models are required.