Experimental study of the Penning ionization of the H₂O molecule by He* (2³S, 2¹S) metastable atoms

Abstract

Penning ionization of the H2O molecule by the He*(21S) metastable atom is studied. The energy shift is measured for the three observed X, A and B electronic bands of the residual H2O+ ion. The absence of the vibrational structures is discussed in light of the known interaction potential surface of the He-H2O complex. More attention is given to the X electronic band characterized by interference structures at high electron energy and an important angular dependence intensity.