Ionization of Atoms by Collision with Excited Atoms. II. A Formula without the Rotating-Atom Approximation

Abstract

A formula for the cross section of the ionization of an atom colliding with an excited atom, A^*+B→A+B⁺+e, was obtained. The calculations to the formula were restricted to the case where the transition A→A^* is optically allowed and the excitation energy of A^* exceeds the ionization potential of B as before. Here all degenerate states of A^* and B+e were taken into account. The present formula gives a cross section which is 23% smaller than the previous result calculated by the use of the rotating‐atom approximation. Besides numerical calculations, an approximation method for the basic equations of the present problem is also shown. This method gives the upper and lower bounds of the approximate cross sections obtainable from the basic equations. Other similar calculations were compared with the present results.