Based on the dynamic characteristics of micro particles in a discharge process

the streamer discharge properties of SF

6

/CF

4

gas mixtures were simulated in uniform electric field. The electron energy distribution functions of SF

6

/CF

4

at different pressures and mixing ratios were obtained by solving two-term Boltzmann equation

which were used to calculate the reduced ionization coefficients and adsorption coefficients. Th

e coefficients were put into a fluid model to simulate the SF

6

/CF

4

streamer discharge process at 0.1 MPa and in a 5 mm gap. The variation of electron number density with time and space were studied. Results show that α/N is increasing with higher E/N at a certain mixing ratio

as well as with higher CF

4

volume fraction at a certain E/N.Electron number density in the streamer head increases rapidly with the development of electron avalanche

and the peak value at 5 ns reaches 9.7 ×10

12

m

-3

. However

the plasma conductive channel is formed when gap is broken down totally

and the electron number density is distributed uniformly with an order of magnitude of 10

17

.