Mass-spectrometry and actinometry of the low-pressure arc discharge with an evaporating graphite cathode

Emission spectroscopy, optical actinometry and mass spectroscopy non-equilibrium plasma diagnostics have been applied for the determination of parameters of the low-pressure are discharge with an evaporating graphite cathode in a methane atmosphere. The absolute density of hydrogen atoms and the relative concentration of CH radicals, as well as the degree of dissociation of hydrocarbon CHx (x = 1-4) radicals have been determined as functions of the pressure of methane. The optical properties of the hydrocarbon films deposited by the discharge have been investigated. The results of the investigation show that the transmittance of these films is associated closely with the optical emission intensity ratio of the CH (430 nm) and H alpha (656.2 nm) spectral lines.