Electric-field singlet-triplet anticrossings of the 1snd configurations of 3He atoms

Abstract

We calculated the electric-field splitting of the 1snd 1D and 3D levels of the 3He I spectrum for n = 3,4 and 5 and evaluated the anticrossings of singlet and triplet Stark substates. The anticrossing spectra observable after selective excitation of singlet states with asymmetric charge and current distributions are discussed. The anticrossing spectra of 3He I differ significantly from those of 4He I due to the hyperfine interaction and, therefore, provide a valuable means for investigations on collisional excitation of He atoms.