Photoionization study of HgAr

Abstract

Photoionization efficiency data for HgAr+ have been obtained in the region of 680–1240 Å. The ionization energy of HgAr was determined to be 10.217±0.012 eV. This value allows the calculation of the dissociation energy of HgAr+ to be 0.228±0.017 eV. The relative probabilities for the formation of HgAr+ via the reactions Ar* ⋅ Hg or Hg* ⋅ Ar→ HgAr+ +e− with Ar* and Hg* prepared in high Rydberg states in the energy range of 10.22–15.79 eV were estimated. Although the radii for the 3d and 5s Rydberg ortitals of Ar have similar values, the probabilities for the formation of HgAr+ from Hg ⋅ Ar* with Ar* in the 5s[3/2]01 and 5s′[1/2]01 Rydberg states are substantially greater than those when the Ar* excited atoms are in the 3d[1/2]01, 3s[3/2]01, and 3d′[3/2]01 Rydberg levels. The ratio for the cross sections for the formation of HgAr+ from Hg ⋅ Ar* with Ar* formed in the 3d[1/2]01 and 4d[1/2]01 states, as well as that with Ar* prepared in the 5d[1/2]01 and 6d[1/2]01 states, were found to be consistent with the predictions of the previous impact parameter calculations.