Resonant Structure in Near-Threshold Electron Excitation of Krypton

Abstract

Using a monochromator-analyzer combination, electron-excitation functions of the lowest-lying clectronic states of krypton have been obtained at a scattering angle of 45 deg in the near-threshold region (9-14 eV). All excitation functions display a complex resonant structure. Additional data have been obtained on elastic scattenng at 45 deg to provide further infonnation on the resonances. In addition to the /sup 4/p/sup 5/5/sup s/sup 2/ J = 3/2, 1/2 resonance doublet, a number of narrow resonances appear below about 12 eV in both the excitation data and elastic scattering which correlate in energy with recent measurements on transmission by Sanche and Schulz. Broad resonant structure is found in a number of the excitation curves and the excitation process in the near- threshold region appears to be dominated by resonant effects. An analysis of the elastic-scattering data on the 4p/sup 5/5s/sup 2/ doublet is pre sented and resonance parameters obtained compared with theory. A comparison of the narrow resonant structure data with optical absorption data on Rb I obtained by Beutler indicates that the narrow resonances in the l0.5-l2-eV region are probably due to levels of the 4p/sup 5/5s4d configuration. (auth)