VUV Lasing in Hydrogen and Fluorine in Diffuse Discharges Formed by Runaway Electrons

• Published in: Bulletin of the Lebedev Physics Institute Vol. 50; no. Suppl 1; pp. S1 - S10
• Main Authors: Panchenko, A. N., Tarasenko, V. F., Kozhevnikov, V. V.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.07.2023; Springer Nature B.V
• Subjects: Discharge; Fluorine; Inhomogeneous electric fields; Ionization waves; Lasers; Lasing; Mixtures; Neon; Physics; Physics and Astronomy; Preionization; Pulse duration; Radiation; Rare gases; efficient VUV lasing; runaway electrons; inhomogeneous electric field; diffuse discharge
• ISSN: 1068-3356; 1934-838X
• DOI: 10.3103/S1068335623130092

The paper studies the parameters of stimulated VUV radiation generated by diffuse discharges formed in a strongly inhomogeneous electric field in mixtures of noble gases with addition of hydrogen and fluorine at pressures up to 10 atm. Efficient VUV lasing on molecular transitions of hydrogen (148–161 nm) and fluorine (157 nm) has been obtained. It is shown that the addition of helium and neon buffer gases increases the pulse duration and lasing energy of the H 2 laser. Laser pulses with a duration of more than 10 ns and a radiation energy of 0.1 mJ were obtained. It has been found that, in mixtures of He with F 2 , a diffuse discharge is formed due to ionization waves. It is shown that the laser pulse at a wavelength of 157 nm has three maxima, which correspond to the first three half-cycles of the diffuse discharge current. It has been found that, depending on the composition and pressure of the mixture, the first or second lasing peak has the highest intensity. At a mixture pressure of 10 atm, the electrical efficiency of the F 2 laser was 0.18%, which exceeds the efficiency of known lasers of this type pumped by volume discharges with preionization from an additional source.