Source of High-Efficiency Radiation in the Lyman and Werner Bands of a Pulse Discharge in Mixtures of Hydrogen and Helium

A numerical model of a pulsed self-sustained discharge in mixtures of H₂ and He is created to describe spontaneous emission in Lyman and Werner bands. The model considers processes involving the electronic and vibrational states of H₂, the electronic states of helium and hydrogen atoms, positive and negative ions, and spontaneous emission in Lyman and Werner bands with allowance for its trapping. Equations of electron–vibrational kinetics are solved along with the Boltzmann equation for the electron energy distribution function, equations of the external electrical circuit, and equations describing preionization by a beam of fast electrons. A simplified model with effective VV exchange constants is used for the vibrational kinetics of hydrogen molecules, allowing the number of necessary calculations to be reduced. Processes of electron attachment and detachment during collisions with vibrationally excited H₂ molecules are considered. The model is verified by a detailed comparison with experimental data on discharge characteristics and radiation energy available in the literature. It is shown that in a pulsed discharge with preionization, the efficiency of radiation in Lyman and Werner bands can be as high as 16% of the energy deposited in the discharge.