Molecular dynamics study of scattering of nitrogen from a cryogenic nitrogen surface

Abstract

The non-equilibrium gas-surface interactions (GSI) between hot nitrogen gas and 4.3 K nitrogen ice were investigated. For this, molecular dynamics (MD) scattering simulations were carried out, comparing a flat and a rough aggregated surface model. The sticking probability and accommodation coefficients were determined for use in direct simulation Monte Carlo (DSMC) simulations. It was found that the sticking probability is similar for both models, but not unity despite the low wall temperature of 4.3 K and the accommodation coefficients correspond to partial accommodation. Additional focus is laid on uncertainty estimation, initial and final energy distributions and the modeled system size.