Total Penning ionization cross sections of Cd and Zn for He(2 3S1) atoms

Abstract
The total Penning ionization cross sections for Cd and Zn for He(2 3S1) atoms have been measured. The method used was that of Penning ion collection from a vapor cell through which a He(2 3S1) beam was passed. The beam energy was 66 meV with a velocity spread of 45%. The measured cross sections were 60(±22) and 17(±7) Å2 for the Cd and Zn targets, respectively.