TY - JOUR

T1 - Uv continuum emission and diagnostics of hydrogen-containing nonequilibrium plasmas

AU - Lavrov, Boris P.

AU - Melnikov, Alexei S.

AU - Käning, Marko

AU - Röpcke, Jürgen

PY - 1999/1/1

Y1 - 1999/1/1

N2 - The emission of the radiative dissociation continuum of the hydrogen molecule [Formula Presented] electronic transition) is proposed to be used as a source of information for the spectroscopic diagnostics of nonequilibrium plasmas. The detailed analysis of excitation-deactivation kinetics, rate constants of various collisional and radiative transitions, and fitting procedures made it possible to develop two methods of diagnostics of (1) the ground [Formula Presented] state vibrational temperature [Formula Presented] from the relative intensity distribution, and (2) the rate of electron impact dissociation [Formula Presented] from the absolute intensity of the continuum. The known method of determination of [Formula Presented] from relative intensities of Fulcher-[Formula Presented] bands was corrected and simplified due to the revision of [Formula Presented] transition probabilities and cross sections of [Formula Presented] electron impact excitation. General considerations are illustrated with examples of experiments in pure hydrogen capillary-arc and [Formula Presented] microwave discharges. In pure [Formula Presented] plasma the values of [Formula Presented] obtained by two independent methods are in rather good accordance [Formula Presented] In the [Formula Presented] microwave plasma it was observed that the shape of the continuum depends on the ratio of the mixture components. Absorption measurements of the population of the [Formula Presented] levels of Ar together with certain computer simulations showed that the [Formula Presented] excitation transfer plays a significant role. In our typical conditions (power flux: [Formula Presented] pressure [Formula Presented] the following values were obtained for the microwave discharge: [Formula Presented] The contribution of the excitation transfer is about 10–30 % of the total population of the [Formula Presented] state.

AB - The emission of the radiative dissociation continuum of the hydrogen molecule [Formula Presented] electronic transition) is proposed to be used as a source of information for the spectroscopic diagnostics of nonequilibrium plasmas. The detailed analysis of excitation-deactivation kinetics, rate constants of various collisional and radiative transitions, and fitting procedures made it possible to develop two methods of diagnostics of (1) the ground [Formula Presented] state vibrational temperature [Formula Presented] from the relative intensity distribution, and (2) the rate of electron impact dissociation [Formula Presented] from the absolute intensity of the continuum. The known method of determination of [Formula Presented] from relative intensities of Fulcher-[Formula Presented] bands was corrected and simplified due to the revision of [Formula Presented] transition probabilities and cross sections of [Formula Presented] electron impact excitation. General considerations are illustrated with examples of experiments in pure hydrogen capillary-arc and [Formula Presented] microwave discharges. In pure [Formula Presented] plasma the values of [Formula Presented] obtained by two independent methods are in rather good accordance [Formula Presented] In the [Formula Presented] microwave plasma it was observed that the shape of the continuum depends on the ratio of the mixture components. Absorption measurements of the population of the [Formula Presented] levels of Ar together with certain computer simulations showed that the [Formula Presented] excitation transfer plays a significant role. In our typical conditions (power flux: [Formula Presented] pressure [Formula Presented] the following values were obtained for the microwave discharge: [Formula Presented] The contribution of the excitation transfer is about 10–30 % of the total population of the [Formula Presented] state.

UR - http://www.scopus.com/inward/record.url?scp=0001208982&partnerID=8YFLogxK

U2 - 10.1103/PhysRevE.59.3526

DO - 10.1103/PhysRevE.59.3526

M3 - Article

AN - SCOPUS:0001208982

VL - 59

SP - 3526

EP - 3543

JO - Physical Review E

JF - Physical Review E

SN - 1539-3755

IS - 3

ER -