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Title: Theory of electron capture from a hydrogen-like ion by a bare ion with extensions to inner-shell capture

Thesis/Dissertation ·
OSTI ID:5007294

A complete systematic derivation is given of a new approximation for the calculation of the cross section for electron capture from a hydrogen-like ion of large nuclear charge Z/sub T/e by a bare ion of charge Z/sub p/e moving with speed v. The amplitude in the wave treatment is obtained through consistent expansion in the small parameters Z/sub p//Z/sub T/ and Z/sub p/e/sup 2//hv; however, the ratio Z/sub T/e/sup 2//hv is not assumed small. Electron-target nucleus interactions are included to all orders and electron-projectile interactions were included consistently to first order so that the theory is called the strong potential Born (SPB). Following a careful analysis of the approach to the energy shell, an off-shell factor is seen to arise which does not appear in the impulse approximation (IA). The effects of this factor on the capture amplitude are explored. It is shown that, in comparison with the IA, the correct weighting of the target spectrum of intermediate states in the SPB significantly alters the 1s ..-->.. ns cross section and at the same time makes peaking approximations to the amplitude more realistic, even for intermediate velocity Z/sub p/e/sup 2//h<<< 1. Instituting a one-electron model, K-shell capture cross sections and probabilities for protons on carbon, neon, and argon are calculated and compared with experiment.

Research Organization:
Nebraska Univ., Lincoln (USA)
OSTI ID:
5007294
Resource Relation:
Other Information: Thesis (Ph.D.)
Country of Publication:
United States
Language:
English