Revue des sciences et sciences de l’ingénieur
Volume 6, Numéro 2, Pages 18-25

Electron-monatomic Gas Scattering Cross Sections Calculation And It’s Effect On The Electrons Beam Profil In The Environmental Scanning Electron Microscopy (esem)

Authors : Omar Mansour .

Abstract

Optimizing experimental conditions under gaseous environment (low vacuum) is a compulsory step before imaging and performing microanalysis in environmental scanning microscopy, especially at low energy. For this task, simulations Monte Carlo are needed that require the knowledge of cross sections. In this work, the complex optical potential is used to calculate electron-gas scattering cross sections in the low and intermediate energy range for two monatomic gases, argon and helium. Comparisons are made with experimental and theoretical cross sections from the literature. The results show that for helium, the EPT( Extended Previous Theory) model works very well, especially at intermediate energies, which is not the case for the argon gas.

Keywords

optical potential ; scattering cross section ; ESEM ; skirt radius ; Monte Carlo