ON MIXING OF 2P53S EXCITED NEON ATOMS IN HIGHLY NONEQUILIBRIUM PLASMA

The experimental study of highly non-equilibrium neon plasma has been carried out when the 2p(5)3s excited state atom density essentially exceeds the electron concentration. The initial electron density N(eo) was between 10(9) and 10(10) cm-3, the density of the ground-state atoms N was within the limits 10(17)-10(18) cm-3 and the reduced electric field E/N varied between 5 and 25 Td. The plasma was created as a result of an interaction between the stationary background and the pulsed electric fields. The excited atom and electron density growth induced by the stepwise electric field variations were found to be of an explosive character due to the accumulation of atoms in the lowest-lying excited states. The binary chemi-ionization reactions of the excited atoms were shown to play the principal role in the kinetics of the excited atoms and electrons. Due to the generation of fast electrons during the chemi-ionization processes, the electron energy distribution function was found to be a highly non-equilibrium one. This leads to the non-equilibrium density distribution over the excited levels of the neon atom. For the given conditions, the 2p(5)3s excited neon atom levels were shown to be mixed due to the presence of electrons with different energies that allowed us to estimate the electron temperature by means of their relative populations.