Wavelengths and Energy Levels of Neutral Kr84 and Level Shifts in All Kr Even Isotopes

Interferometrically-measured wavelengths of 109 lines of neutral Kr84 are compared with those of Kr86. Sixty energy levels of neutral Kr84 derived from those wavelengths and 25 Kr86-Kr84 isotope shifts previously measured are given along with their shifts from the energy levels of Kr86. Twenty levels of each of Kr82, Kr80, and Kr78 are also evaluated using isotope-shift information in the literature. The differences between the experimentally observed shifts and the normal mass shift leave large negative residuals which are accounted for by ionization energy differences and by the specific mass shift. It appears that the volume effect causes only a very small, if any, energy level shift.