Fivefold differential cross sections for the ionization of aligned hydrogen molecule by electron and positron impact

Abstract

We report five-fold differential cross section (5DCS) for the ionization of aligned hydrogen molecule by electron and positron impact in coplanar geometry. The calculations have been performed for an incident energy of 200 eV and ejection energies of (3.5±2.5) and (16±4) eV. The present calculations are based on the eikonal approximation due to Glauber, and the BBK approximation. The positron-impact ionization cross sections obtained in the BBK and GA-PCI methods are found to be higher than the electron-impact cross sections in the binary region while the converse is true for the recoil regime. In case of positron impact, the binary peaks predicted by both the GA-PCI and BBK models shifted away from the direction of momentum transfer, and showed a trend which is opposite to the case of electron impact ionization.

Differential studies and projectile charge effects in ionization of molecular nitrogen by positron and electron impact

“…One particular interest in comparing positron and electron impact data are differences in the interaction kinematics associated solely with the opposite projectile charges. These differences provide stringent tests of theory because first-order perturbation theories predict identical total and differential cross sections for higher energy electron and positron impact whereas more sophisticated approximations developed in the 1980's and 90's predicted differences in the differential electron emission measured as a function of the momentum transfer [2][3][4][5][6][7][8][9][10][11][12][13]. For example, in fully kinematic studies the binary electron emission (resulting from 2-body interactions involving just the incoming projectile and a single target electron with the other bound electrons and target nucleus acting as non participating spectators) was predicted to be enhanced (reduced) for positron (electron) impact; while just the opposite was predicted for the recoil intensity (corresponding to interactions where the ejected electron also interacts with the target nucleus as it leaves).…”

“…Many theoretical studies performed since then arrive at similar predictions. [10][11][12][13] On the experimental side, few differential comparisons between positron and electron impact data are available. This is because such measurements are difficult for positron impact due to the low signal intensities that are currently available.…”

Inverse bremsstrahlung heating rate for dense plasmas in laser fields

“…They have pointed out that the eikonal approximation is superior to the FBA in the present physical process. It is worth stressing that the EA has been found to be successful in a wide variety of collisions [31][32][33][34][35][36][37] than that obtained in the FBA and classical-simulation 16 methods with the screened Rogers potential in a wide range of mean kinetic energy for Xe 6þ and Xe 10þ ions.…”

Relativistic Ionization of Hydrogen Atoms by Positron Impact

“…During the past few years, the theoretical study of positron-atom ionization collisions on differential cross sections has become increasingly interesting for relativistic [11] as well as non-relativistic [12][13][14][15] energies. The ionization process of a positron with a hydrogen atom attracts much attention as one of the simplest three-body Coulomb systems.…”