H, He, Ne, Ar-bombardment of amorphous hydrocarbon structures

Amorphous hydrogenated carbon films have found various applications due to the unique combination of properties of this material. In tokamak-like fusion reactors, this material is subject to bombardment primarily by H, but also to smaller amounts of noble gas ions. The effect of these low energy noble gas ions on the erosion of carbon is however not known. In this work, both cumulative and non-cumulative bombardment simulations were performed of hydrogen, helium, neon, and argon ions impinging onto a-C:H surfaces at energies ranging from 2 to 10 eV, employing a reactive hydrocarbon potential model. At noble gas/hydrogen ratios of 1/10 we saw no significant difference between the sputtering yields obtained from the bombardment simulations of different noble gas ions. A marked difference in the surface morphology was, however, observed between the final simulation cells from the 5 eV and the 10 eV ion bombardment simulations.