Penning excitation cross sections for the individual CdII states by He(23S) metastable atoms

The branching ratios of the Penning excitation for the individual Cd II states by He(2 3 S) atoms were measured using Penning electron spectroscopy. Using the value of the total Penning excitation cross section measured by Schearer and Padovani (1970) the excitation cross sections for the upper and lower states of the Cd II 441.6 nm laser line are determined to be 0.54 and 0.14*10 -15 cm 2 , respectively. Those of the Cd II 325.0 nm laser line are equal to the above values, respectively, within the limits of error of the determination. The excitation cross section for the CdII ground state is 2.8*10 -15 cm 2 .