Multichannel quantum defect theory and high-resolution spectroscopy of the hyperfine structure of high Rydberg states of83Kr

Abstract

The hyperfine structure of ns and nd Rydberg states of {sup 83}Kr has been measured in the range n=30-190 below the {sup 2}P{sub 3/2} ionization threshold by pulsed-field ionization following single-photon excitation from the {sup 1}S{sub 0} ground state using a narrow-bandwidth vacuum-ultraviolet laser system. A multichannel quantum defect theory (MQDT) treatment of the hyperfine structure in Rydberg states of the rare-gas atoms has been developed that quantitatively accounts for the effects of the nuclear spin on the spectral structures over the entire range of principal quantum number investigated. The model allows the parametrization of the hyperfine structure of the Rydberg states in terms of the ionic hyperfine structure and relies on the assumption that the interaction with the nuclear spin is negligible in the close-coupling region of the electron-ion collision, an assumption that is also expected to be valid in other atomic and molecular systems. Improved eigen quantum defects for the ns and nd Rydberg series with J=1 and 2 have been derived from the MQDT analysis, and the hyperfine structure of the two {sup 2}P{sub 3/2} and {sup 2}P{sub 1/2} spin-orbit components of the ground state of {sup 83}Kr{sup +} has been determined.