Measurement and Modeling of Hydrogen Molecule Ro-Vibrational Accommodation on E-204 Polycrystalline Graphite

Abstract

The loss rate of H2 and D2 internal ro-vibrational energy in collisions with an E-294 polycrystalline graphite surface is measured in a plasma-free environment. Accommodation coefficients are found to be approximately 0.01�0.2 for vibrational energy and somewhat larger, 0.05�0.2 for rotational energy, with a slight increasing trend seen with increasing surface temperature. Molecular dynamics simulations of the experiment give a total ro-vibrational accommodation rate of order 0.1, which is consistent with the data at higher surface temperatures.