Electron Swarm Parameters in $\hbox{c-C}_{4} \hbox{F}_{8}$ and $\hbox{CO}_{2}$ Gas Mixtures From Boltzmann Equation Analysis

The electron swarm parameters in c-C
₄
F
₈
/CO
₂
gas mixtures, including the density-normalized effective ionization coefficient (α-η)/
N
and the drift velocity
V
_e
, are calculated for the overall density-reduced electric-field strength
E
/
N
values from 150 to 600 Td (1 Td = 10
^-17
V · cm
²
). These calculations have been performed through solving the Boltzmann equation under the two-term approximation in the condition of steady-state Townsend experiment. The c-C
₄
F
₈
content
k
in the gas mixtures can be varied over the range of 0%-100 %. From the variation curve of (α-η)/
N
with the c-C
₄
F
₈
mixture ratio
k
, the limiting field strength (
E
/
N
)
_lim
for each c-C
₄
F
₈
concentration is determined for the analysis of the insulation characteristics of the c-C
₄
F
₈
/CO
₂
mixture. Additionally, the global-warming potential and the liquefaction temperature of c-C
₄
F
₈
/CO
₂
gas mixtures are also taken into account to evaluate the possibility of applying in gas insulation of power equipment.