Transfer of rovibrational energies in hydrogen plasma–carbon surface interactions

We present state-of-the-art molecular dynamics (MD) simulations of high-density plasma-bombardment of carbon, mimicking plasma–wall interactions at the fusion reactor first wall. Bare and hydrogenated amorphous carbon surfaces with temperatures in the range of 300–800 K are bombarded by a distribution of neutral hydrogen molecules representing well-defined center-of-mass and rovibrational temperatures. The MD simulations are benchmarked against experiments in which a heated carbon surface is irradiated with hydrogen molecules from a plasma source. Comparisons between simulations and experiment are presented for the rovibrational distributions upon reflection and the rotational and vibrational accommodation coefficients.