Kinetic processes in a highly-ionized non-equilibrium hydrogen plasma

Abstract

The work represents a ramified kinetic scheme of plasma chemical processes in a non-equilibrium hydrogen plasma that allows one to model in detail the dynamics of an electric discharge in a molecular gas. The scheme describes processes of interaction of electrons with heavy particles (including a vast set of processes of electronic-vibrational excitation of hydrogen molecules by electron impact), vibrational kinetics of the H₂ molecules and processes with participation of hydrogen atoms, positive and negative ions. The possibility of reaching a high level of vibrational non-equilibrium of the molecular component of the gas under conditions characterized by high values of gas temperature and concentration of atomic hydrogen (which is an effective quencher of the vibrational levels of the H₂(X) particles) is demonstrated by the example of the pulsed high-current low-pressure discharge. Such a possibility is conditioned by the high efficiency of the processes of vibrational excitation of hydrogen molecules via singlet electronic terms. It is also shown that quick gas heating during the discharge at sufficiently high electron energy (T_e>or=2 eV) is substantially governed by the processes of dissociative excitation of electronic states of the hydrogen molecules by direct electron impact.