Scattering of Metastable Helium Atoms in Helium, Neon, and Argon

Abstract

Total collision cross sections for the scattering of metastable 2³S and 2¹S He atoms in helium, neon, and argon have been measured using a thermal‐energy atomic beam in which a fraction of the helium atoms are excited by electron bombardment. The excited particles are detected by measuring the secondary electron emission from metal surfaces. The cross sections for the scattering of the triplet atoms are larger than for the singlet in each case. For neon the difference is considerably greater than the estimated experimental error, indicating a large difference in the interaction potentials.