Inelastic ElectronAtom Collisions under NearResonance Conditions: Analysis of Transitions Involving Strong Coupling
Abstract
A method has been devised to calculate the cross sections of inelastic electronatom collisions under nearresonance conditions. This method (referred to as the method of resonance distortion) consists of solving the limiting exactresonance problem as the zerothorder approximation and using this solution to obtain the firstorder solution by an iteration procedure, and is particularly suitable for treating optically allowed transitions produced by electron impact where the coupling between the initial and final states is strong and of longrange type. Application of this method has been made to a schematic model with an isotropic inversesquare interaction potential and to the problem of electronatom collisions with ns>np transition. The general results indicate that (i) for weak coupling the collision strengths calculated by the resonancedistortion scheme reduce to those calculated by the method of distorted waves, (ii) the resonancedistortion method and Seaton's B'II method give nearly equal partial cross sections for large l, and (iii) at very low l, the B'II partial cross sections are substantially larger than those determined from the resonancedistortion method. The total cross sections for the 3s>3p transition in Na have been calculated by the resonancedistortion method for various incident electron energies, and the results show better agreement with experiment than do those of the Born approximation and of Seaton's version of the modified Born approximation.
 Publication:

Physical Review
 Pub Date:
 February 1964
 DOI:
 10.1103/PhysRev.133.A947
 Bibcode:
 1964PhRv..133..947L