Electron impact ionisation cross sections for atomic and molecular allotropes of phosphorous and arsenic

Abstract

We report electron impact total ionisation cross sections for phosphorous (P), arsenic (As), diphosphorous (P 2 ), diarsenic (As 2 ), tetra phosphorous (P 4 ) and tetra arsenic (As 4 ) from the threshold of the target to 2000 eV. We employed spherical complex optical potential to compute total inelastic cross sections (Q inel ). The total ionisation cross section is extracted from the total inelastic cross section using the complex scattering potential-ionisation contribution method. The results of most of the targets studied here compare well with the measurements and the theoretical data wherever available. The correlation between the peak of ionisation cross sections with the number of target electrons and polarisability is also reported. It is observed that the maximum ionisation cross sections depend linearly on the number of target electrons and polarisability of the target. This linear correlation is used to predict the maximum ionisation cross sections for the targets (I 2 , HI and PF 3 ) where no experimental data are available.