Determination of the Penning excitation cross-sections of individual Cd(II) states for He metastable atoms using Penning electron spectroscopy

The relative Penning excitation rates for the individual Cd(II) states by He 21S metastable atoms as well as He 23S metastable atoms were measured separately. The absolute Penning excitation cross-sections for exciting individual Cd(II) states by impact of He 21S atoms were determined by making use of the absolute Penning excitation cross-sections for the Cd(II) states excited by He 23S atoms determined in previous work and Penning collisions between He metastable atoms and Ar atoms. These cross-sections σsub(s)(M) for Cd(II) states M by He 21S atoms are as follows: σsub(s)(5s 2Ssub(1/2)) = 3.9 x 10-15 cm2; σsub(s)(5p 2p) = 0.51 x 10-15 cm2; σsub(s)(5s22Dsub(5/2)) = 0.94 x 10-15 cm2; σsub(s)(5s22Dsub(3/2)) = 1.1 x 10-15 cm2; σsub(s)(6s2 Ssub(1/2), 5d 2D) = 0.85 x 10-15 cm2. (author)