Theoretical study on (e,2e) process for helium in perpendicular geometry

The triple differential cross sections for electron impact ionization helium (e, 2e) reactions are calculated by use of the BBK and modified BBK model at different gun angles of incident electron energy 64.6 eV. The structures of the cross sections and the physical natures of these structures are discussed in detail. It is found that for the non-coplanar geometry, cross sections are determined by a variety of effects together and these effects are converted to each other under different conditions. Moreover, strong dynamical screening effect is observed in the final state of the perpendicular plane symmetric geometry.

A theoretical study on electron impact ionization helium (e, 2e) reactions at 64.6 eV

Chen¹,

Liu²,

Dong³

2012

Influence of screening effect on double differential cross section and single differential cross section for (e, 2e) process of helium

杨欢¹,

邢玲玲²,

张穗萌³

et al. 2013

The double differential cross sections for electron impact single ionization of helium at incident energies of 32.5, 36.5 and 40.7 eV are calculated by using the DS3C model. The calculated results are compared with the experimental date. The exchange effects are discussed. The single differential cross section for electron impact single ionization of helium is obtained by integrating the double differential cross sections over the angle of the ejected electron. The single differential cross sections of helium at incident energies of 32.5, 36.5, 40.7 and 50 eV are calculated by using the 3C model and the DS3C model. The calculated results are compared with the experimental date. The structure of the cross section is analysed and the contribution of exchange effect to the corss section is discussed.

First-order distorted wave Born approximation for single ionization of Ar by electron impact in a coplanar doubly symmetric geometry

Zhang¹,

Chen²,

Wang³

et al. 2014

The first-order distorted wave Born approximation (DWBA) has been performed for single ionization of Ar(3p) by electron impact in coplanar doubly symmetric geometry from near threshold to intermediate energies. Theoretical triple differential cross sections (TDCS) are compared with the latest experimental data. It is found that when the incident electron energies are 40 eV higher than the ionization threshold, for argon, the binary and recoil collision mechanism will dominat as the energies increase, but not in the near threshold energy regime, where the distortion effects are of great significance. In order to completely describe the electron impact ionization of argon, it is imperative that more scattering mechanisms should be considered in the theoretical models.