Millimeter-wave spectroscopy and multichannel quantum-defect-theory analysis of high Rydberg states of krypton:: The hyperfine structure of 83Kr+

The intervals between hyperfine levels of high ns and nd (n=68-76) Rydberg states of Kr-83 have been determined by millimeter-wave spectroscopy. The hyperfine structure of the Rydberg states has been analyzed using multichannel quantum defect theory. Improved eigenquantum defects for the ns and nd Rydberg series and quantitative information about the s-d interaction at the energy of the P-2(3/2) threshold have been obtained, and improved values of the hyperfine structure of the P-2(3/2) ground state of Kr-83(+) have been derived.