Study of carbon dust formation and their structure using inductively coupled plasmas under high atomic hydrogen irradiation

Experiments on erosion and dust formation on graphite materials have been performed using high power induction plasmas containing high atomic hydrogen flux (∼1024 m−2 s−1). Chemical sputtering by atomic hydrogen irradiation with incident energy below 1 eV eroded the graphite targets significantly, and the sputtering yield was roughly estimated to be 0.002–0.005, which is as high as that obtained by ion beam and fusion plasma experiments. The transport of the released hydrocarbon along the gas flow, interacting with low temperature plasmas, results in carbon dust formation on the eroded graphite target and also on the silicon and graphite samples located at the remote position. The dust size and density observed on the samples decreases with distance from the graphite target. The dust shape strongly depends on the target surface temperature, and the graphite dust turns into polyhedral particle like diamond when the surface temperature rises to 1100 K.