"Acta Universitatis Carolinae - Mathematica et Physica" . "P(GA202/07/0495), P(GA202/09/0642), P(GA205/09/1183), P(GD202/08/H057), P(OC10046), S, Z(MSM0021620834)" . . . "We examine establishing of a thermal equilibrium in a H3+-dominated plasma (produced by a microwave discharge ignited in He-Ar-H2 gas mixture) and in its afterglow at temperatures 77-220 K by Cavity Ring-Down Spectroscopy. With respect to the observed population of lowest rotational states of the ground vibrational state of H3+ ion, we conclude that the rotational temperature is well defined and stable. It is equal to the He buffer gas temperature and to the kinetic temperature of the ions. By using para-enriched H2 gas, we achieve high population of para nuclear spin states of H3+ ions in the discharge. This population is not constant in time and evolves towards a steady state (asymptotic) value which is not equal to the thermodynamic equilibrium value for a given temperature. The fact that the value of the steady state para-H3+ fraction does not vary with the concentration of para-enriched H2 indicates that degradation of para-enrichment of H2 in the discharge is negligible." . "1" . . . . "0001-7140" . . . . . "CZ - \u010Cesk\u00E1 republika" . . "Opanasiuk, Sergii" . "7"^^ . "[37421C2A07DF]" . "cavity ring-down spectroscopy; H3+ plasma"@en . "7"^^ . "11320" . "8"^^ . . . "Pla\u0161il, Radek" . "53" . "Equilibrium in Low Temperature H3+-dominated Plasma, Application of Cavity Ring-Down Spectroscopy" . . "Opanasiuk, Sergii" . . . . "Equilibrium in Low Temperature H3+-dominated Plasma, Application of Cavity Ring-Down Spectroscopy"@en . . . "Rubovi\u010D, Peter" . . "Dohnal, Petr" . . . . "Equilibrium in Low Temperature H3+-dominated Plasma, Application of Cavity Ring-Down Spectroscopy" . "RIV/00216208:11320/12:10132621!RIV13-GA0-11320___" . "RIV/00216208:11320/12:10132621" . . . "Varju, Jozef" . "http://auc.karlin.mff.cuni.cz" . "Equilibrium in Low Temperature H3+-dominated Plasma, Application of Cavity Ring-Down Spectroscopy"@en . . . "Glos\u00EDk, Juraj" . . "We examine establishing of a thermal equilibrium in a H3+-dominated plasma (produced by a microwave discharge ignited in He-Ar-H2 gas mixture) and in its afterglow at temperatures 77-220 K by Cavity Ring-Down Spectroscopy. With respect to the observed population of lowest rotational states of the ground vibrational state of H3+ ion, we conclude that the rotational temperature is well defined and stable. It is equal to the He buffer gas temperature and to the kinetic temperature of the ions. By using para-enriched H2 gas, we achieve high population of para nuclear spin states of H3+ ions in the discharge. This population is not constant in time and evolves towards a steady state (asymptotic) value which is not equal to the thermodynamic equilibrium value for a given temperature. The fact that the value of the steady state para-H3+ fraction does not vary with the concentration of para-enriched H2 indicates that degradation of para-enrichment of H2 in the discharge is negligible."@en . "134639" . "Hejduk, Michal" .