Vladimir Gorokhovsky

Characterization of Reversed Arc Hydrocarbon Plasma in Material Processing

S.Avtaeva, V.Gorokhovsky
A comprehensive study of the reversed arc plasma enhanced CVD (RACVD) reactor utilizing
an Ar + H2 + CH4 plasma-creating mixture in the pressure range 1–100 Torr with
a plasma flow direction opposite to the direction of the arc current was carried out. The
reversed arc discharge has rising current–voltage characteristics showing voltage increasing
with pressure and hydrogen concentration. The spectrum of the Ar-H2-CH4 plasma column
includes CH, C2,
and H2
molecular bands, in addition to Hα,
Hβ,
Hγ,
and Hδ
lines. The
dissociation degree of H2
was estimated from the intensity ratio IHα/
IArI of the Hα
and ArI
750 nm lines using the optical actinometry method, yielding an average dissociation degree
of hydrogen in the arc plasma of 15–20%. The average vibrational and rotational temperatures
of CH radicals are Tv = Tr = 3000 K ± 300 K. The dissociation degree of hydrogen in
the reversed arc discharge was calculated by the advection–diffusion-reaction model and
showed reasonably good agreement both with experimental findings and with LTE calculations.
The high concentration of nascent hydrogen and hydrocarbon radicals in the reversed
arc plasma and its uniform distribution across the arc column makes it suitable for diamond
coatings. The results obtained on the interaction of reversed arc plasma with substrates
suspended within the current-carrier arc plasma column were applied to the description of
a dusty reversed arc plasma in fluidized bed reactors. It was found that the energy effectiveness
of the treatment of nanoparticles in the RACVD fluidized bed reactor exceeds 90%.

S.Avtaeva, V.Gorokhovsky
A comprehensive study of the reversed arc plasma enhanced CVD (RACVD) reactor utilizing an Ar + H2 + CH4 plasma-creating mixture in the pressure range 1–100 Torr with a plasma flow direction opposite to the direction of the arc current was carried out. The reversed arc discharge has rising current–voltage characteristics showing voltage increasing with pressure and hydrogen concentration. The spectrum of the Ar-H2-CH4 plasma column includes CH, C2, and H2 molecular bands, in addition to Hα, Hβ, Hγ, and Hδ lines. The dissociation degree of H2 was estimated from the intensity ratio IHα/IArI of the Hα and ArI 750 nm lines using the optical actinometry method, yielding an average dissociation degree of hydrogen in the arc plasma of 15–20%. The average vibrational and rotational temperatures of CH radicals are Tv = Tr = 3000 K ± 300 K. The dissociation degree of hydrogen in the reversed arc discharge was calculated by the advection–diffusion-reaction model and showed reasonably good agreement both with experimental findings and with LTE calculations. The high concentration of nascent hydrogen and hydrocarbon radicals in the reversed arc plasma and its uniform distribution across the arc column makes it suitable for diamond coatings. The results obtained on the interaction of reversed arc plasma with substrates suspended within the current-carrier arc plasma column were applied to the description of a dusty reversed arc plasma in fluidized bed reactors. It was found that the energy effectiveness of the treatment of nanoparticles in the RACVD fluidized bed reactor exceeds 90%.