Theoretical Considerations on Penning Ionization Processes

Abstract

Penning ionization process is discussed from two standpoints of view, namely on the basis of quasiadiabatic and adiabatic representations of electronic states. New cross-section formulas are derived. Green operator technique is applied in the first formalism and a non-local complex potential is derived for the relative motion in the initial channel. In the second formalism Fano’s method is applied and a local complex potential is defined. In a certain limiting case these two formulas reduce to the corresponding BII approximation and the formula obtained by Katsuura, respectively. Though the first formalism is exact as it stands, it is not convenient to use this for more refined practical calculations. It is concluded that the second formalism is more suitable for practical calculations of low energy metastable Penning ionization.