Ionizing Doses Calculations for Low Energy Electrons in Silicon and Aluminum

Abstract

International audienceThe electron transport at low and very low energy (10 eV-2 keV) is investigated with a Monte Carlo (MC) code in silicon and aluminum. The elastic scattering with nuclei is described by Mott's model of partial waves, whereas the inelastic collisions with electrons are described by the complex dielectric function theory. Comparisons of MC simulations with electron emission yields (EEY) and energy loss spectra experimentally measured in ultrahigh vacuum on Ar-etched samples are given. The practical ranges and the ionizing dose calculations are presented down to 10 eV for electrons in silicon and aluminum. The simulation results show a correlation between the EEY and the ionizing doses. At low energy, while the electrons stay in the first ~10 nm from the surface due to the elastic scattering, the EEY increases and the ratio of the ionizing dose over the incident energy decreases. Above 200 eV, when the electrons go deeper into the solid due to the inelastic scattering, the EEY decreases and the ionizing dose ratio increases

Effect of rectangular grooves and checkerboard patterns on the electron emission yield

“…[4][5][6] . Our previous work 22,23,25,26 shows that for aluminum and silver a relatively good agreement is found between MicroElec simulations, the experimental data from the DEESSE facility made by Gineste 5 , and the data of Bronstein et al 28 . The maximum EEY 𝜎 and the energy of the crossover points 𝐸𝑐 1 and 𝐸𝑐 2 (energy for which the EEY is equal to 1) are summarized in Table 1 for a flat sample of silver.…”

“…The physical models of the new version of MicroElec have been compared to the code OSMOSEE [23][24][25][26] . At low energy, the trajectory of electrons in matter is driven by two main mechanisms: the elastic (i.e.…”

“…The inelastic cross sections have been calculated using the complex dielectric function theory as described in Refs. 20,21,23,[25][26][27] and the references therein. To extend the code MicroElec at lower energies, the inelastic cross sections have been calculated down to a few eV.…”

Surface Ionizing Dose for Space Applications Estimated With Low Energy Spectra Going Down to Hundreds of Electronvolt

“…4. The two discrete models MICROELEC [26]- [29] and OSMOSEE [30] are very close to each other. In both cases the elastic processes are simulated according to the ELSEPA cross sections [35], while the standard multiple scattering process of GEANT4 is used in G4EmStandardPhysics_option4 and the Livermore scenario.…”

“…The dose is calculated for low energies and small dimensions with different models in order to investigate, the relevance of continuous transport processes. Continuous based models are compared to calculations that use discrete transport methods (MICROELEC and OSMOSEE [30], [31]). The anlysis is focused on two GEANT4 scenarios:…”