Resonant excitation series at the Kr 3p and Xe 4p thresholds

I.T. Steinberger¹, B. Wassermann², C.M. Teodorescu³, G. Reichardt⁴, D. Gravel³,
C.W. Hutchings⁵, A.P. Hitchcock⁶, R. Flesch³ and E. Rühl³

1. Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel
2. Fachbereich Chemie, Freie Universität Berlin, Takusstrasse 3, D-14195 Berlin, Germany
3. Fachbereich Physik, Universität Osnabrück, Barbarastrasse 7, D-49069 Osnabrück,Germany
4. BESSY GmbH, Lentzeallee 100, D-14195 Berlin, Germany
5. Behlen Laboratory  of Physics, University of Nebraska, Lincoln, NE 68588-0111 USA
6. Department of Chemistry, McMaster University, Hamilton, Ontario L8S 4M1, Canada

    A systematic comparison is presented between the gas phase and solid phase features of resonant core excitation series in  3p excited krypton and 4p excited xenon. For the gases total ion  yield  spectra were recorded. For the solids, photoemission yield (total electron yield) spectra were complemented with photoconductivity excitation spectra, recording electron transport in the conduction band.   The gas phase spectra were compared with predictions of recent theoretical work [M. Ohno, Phys. Rev. A51, 1042 (1995)] and approximated by means of the simple Rydberg formula with constant quantum defect. The core excitation series observed in the solids are analogous to Mott-Wannier valence exciton series, as transitions from the respective core levels into the lowest conduction band are dipole allowed.  Similarly to the case of valence excitons, the series limit of these core excitons was found to correspond to a rise in the photoconduction signal, marking the onset of direct transitions into the conduction band. However, the core exciton energies are  close to the gas phase Rydberg state energies,  in contrast with the valence excitons that have binding energies considerably smaller than the respective valence Rydberg states in the gas. The energies of the core excitons observed cannot be described by means of the effective reduced exciton mass and the dielectric constant:  the simple Mott-Wannier effective mass model is inadequate for these excitons. [S0163-1829(99)09529-6]