Chemical sputtering of graphite bombarded with a deuterium ion beam

The chemical sputtering of graphite was carried out in an ultrahigh vacuum chamber of secondary ion mass spectrometer. An incident energetic deuterium ion beam was used separately or in combination with an electron beam, to simulate plasma irradiation. The temperature of the graphite sample was regulated from room temperature to 1000 K. The sputtering products with m/e from 2 to 44 as a released molecule beam from the irradiated graphite sample have been analysed in situ with a quadruple mass spectrometer SQ156. The temperature characteristic of releasing the de utero-methane CD4 from graphite SMF-800 sample bombarded with a deuterium ion beam of 1.3 μA/3 keV has been obtained. The releasing peak of CD4 due to enhanced chemical sputtering is at about 780 K. A formula for the CD4 releasing rate is proposed as γ = AnD nCD3 exp (-ER/RT). The activation energies ER of 5.2 kCal/mol for CD4 formation and E1 of 35.8 kCal/mol for the synthetic thermal desorption of deuterium atom D and deuteron-methyl CD3 from the surface region of the graphite were fitted out experimentally