5p 2P Research Articles

Mean Lives of the 2p, 3p, 4p, 5p, and 6p 2P Levels in He II

The resonance lines of He II were studied with the beam-foil technique. Helium beams from a Van de Graaff accelerator were sent through a thin exciter foil, and the emitted radiation was analyzed with a 3-meter grazing incidence spectrometer. Mean lives were measured for the 2p, 3p, 4p, 5p, and 6p 2P levels in He II. The results are in good agreement with theory.