Accession Number : AD0448331

Title :   ASYMPTOTIC FORM OF THE ELECTRON CAPTURE CROSS SECTION IN FIRST BORN AND DISTORTED WAVE APPROXIMATIONS,

Corporate Author : AIR FORCE CAMBRIDGE RESEARCH LABS HANSCOM AFB MA

Personal Author(s) : Mapleton, R. A.

Report Date : 03 MAR 1964

Pagination or Media Count : 11

Abstract : The first Born approximation with both the proton-proton and proton-electron interaction is used to calculate the high energy electron capture cross section. It is shown that the high energy proton-nucleus amplitude has a dominant peak for backward scattering (centre-of-mass system). As a consequence of this peak, if the protons are treated as distinguishable particles, the cross section depends upon the impact energy E as E(3-) in contrast to the commonly accepted E(6-) dependence. When the protons are treated as indistinguishable particles, the electron capture cross section is not defined at sufficiently high energies. This same cross section is also calculated using the distorted wave approximation as developed by Bassel and Gerjuoy in 1960. It is shown that the proton-nucleus amplitude is only cancelled in the forward direction, and consequently the electron capture cross section is again not defined at high energies. (Author)

Descriptors :   (*ELECTRON CAPTURE, NUCLEAR CROSS SECTIONS), HELIUM, HYDROGEN, PROTON REACTIONS, NUCLEAR SCATTERING.

Distribution Statement : APPROVED FOR PUBLIC RELEASE