Partial ionization cross sections of Silicon by Electron impact Ionization process

Sushil Kumar

doi:10.17485/ijst/v14i2.1893

Abstract

Electron-impact single-ionization cross sections of Si by electron impact have been solved theoretically for the full range of kinematics and collision geometries of practical interest by S.P. Khare theoretical model. The corresponding partial and total ionization cross sections have also been derived in the energy range varying from ionization thresholds to 6000 eV. Comparison of the evaluated partial and total ionization cross sections is made with the experimental and theoretical data wherever available. Objective:Our objective is to find the partial and total ionization cross sections Silicon atom and its fragmentation ion at different energy levels and analysis of results with other available data. Method: In this present work we have measured partial ionization cross sections of Silicon atom using semi-empirical formalism of Jain & Khare due to electron impact at incident electron energy from ionization threshold to 6000 eV. Findings: Comparison of the evaluated partial and total ionization cross sections is made with the experimental and theoretical data wherever available. A good agreement is observed when we compared our data for electron impact ionization cross section for Silicon and its fragment ions. Also some disagreement is found between our data and other available data. Our results are higher for Si2+, Si4+, Si5+ and Si6+ fragment ions. For Silicon atom, good agreement between theory and experiment is achieved. Novelty: The total ionization cross-sections by electron impact of atoms are required in the study of plasma diagnostics, astrophysical and fusion applications, radiation physics, mass spectrometry, ionization in gas discharge, modeling of fusion plasmas, modeling of radiation effects for both materials & medical research and astronomy. We have calculated partial and total ionization cross section for higher energy range i.e from threshold to 6000 eV, which have not been done by other researchers. Keywords: Ionization; cross section; electron impact

Highlights

The electron-impact ionization cross section is one of the fundamental properties of atoms and molecules for its intrinsic importance in atomic collision theory, and for a wide scope of uses, for example, fusion plasma diagnostics, modeling of semiconductor etching in plasma reactors, radiation effects on materials and astrophysics
The agreement between theoretical predictions and experiment has been constantly improving, especially for the fundamental target of atomic hydrogen, which is claimed to have been numerically solved with non-perturbative approaches such as (i) exterior complex scaling (ECS) [3,4], (ii) convergent close coupling (CCC) [5], and (iii) time-dependent close coupling (TDCC) [6]
Kumar & Bhatt / Indian Journal of Science and Technology 2021;14(2):181–189 In Figures 3, 4 and 5, we report the cross sections for the production of Si3+, Si4+ and Si5+ ions through electron impact from threshold to 6000 eV

Summary

Introduction

The electron-impact ionization cross section is one of the fundamental properties of atoms and molecules for its intrinsic importance in atomic collision theory, and for a wide scope of uses, for example, fusion plasma diagnostics, modeling of semiconductor etching in plasma reactors, radiation effects on materials and astrophysics. The convergent close-coupled (CCC), methodology for a general discussion of this method has provided the best correlation of scattering theory with experimental results [7] This method is computationally intensive and is currently limited to the valence shell of atoms containing only one or two valence electrons. M.Baetrschy’s work has described the exterior complex scaling (ECS) method, which requires massively parallel supercomputing to solve the three-body problem without significant approximation This has provided very accurate theoretical results for hydrogen at low incident energies, but will require significant advances in computing technology before it can be applied to larger atoms [8]. Electron impact ionization of atoms and molecules is of primary importance in mass spectrometry, plasma processes, and atmospheric science[9,10,11,12,13]

Theory

Result and Discussion

Conclusion