Above this density, microwave field will damp rapidly, so the gas ionization is mainly on the surface.
超过此密度后，微波场在表面快速衰减，气体电离主要在表面进行。
2
A dynamic equation of plasma density is constructed about ionization, recombination, diffusion and plasma flow which is produced by inhomogeneous pressure.
Thetheoretical calculations and the experiments suggest that, double pre-ionization has an obvious advantage for increasing the initial electron density between the main electrodes.