11 research outputs found
UV continuum emission and diagnostics of hydrogen-containing non-equilibrium plasmas
For the first time the emission of the radiative dissociation continuum of
the hydrogen molecule ( electronic
transition) is proposed to be used as a source of information for the
spectroscopic diagnostics of non-equilibrium 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
new methods of diagnostics of: (1) the ground state
vibrational temperature from the relative intensity
distribution, and (2) the rate of electron impact dissociation
(d[\mbox{H_{2}}]/dt)_{\text{diss}} from the absolute intensity of the
continuum. A known method of determination of from relative
intensities of Fulcher- bands was seriously corrected and simplified
due to the revision of transition probabilities and cross sections of
electron impact excitation. General considerations are illustrated
with examples of experiments in pure hydrogen capillary-arc and H+Ar
microwave discharges.Comment: REVTeX, 25 pages + 12 figures + 9 tables. Phys. Rev. E, eprint
replaced because of resubmission to journal after referee's 2nd repor
Optimal values of rovibronic energy levels for triplet electronic states of molecular deuterium
Optimal set of 1050 rovibronic energy levels for 35 triplet electronic states
of has been obtained by means of a statistical analysis of all available
wavenumbers of triplet-triplet rovibronic transitions studied in emission,
absorption, laser and anticrossing spectroscopic experiments of various
authors. We used a new method of the analysis (Lavrov, Ryazanov, JETP Letters,
2005), which does not need any \it a priory \rm assumptions concerning the
molecular structure being based on only two fundamental principles:
Rydberg-Ritz and maximum likelihood. The method provides the opportunity to
obtain the RMS estimates for uncertainties of the experimental wavenumbers
independent from those presented in original papers. 234 from 3822 published
wavenumber values were found to be spurious, while the remaining set of the
data may be divided into 20 subsets (samples) of uniformly precise data having
close to normal distributions of random errors within the samples. New
experimental wavenumber values of 125 questionable lines were obtained in the
present work. Optimal values of the rovibronic levels were obtained from the
experimental data set consisting of 3713 wavenumber values (3588 old and 125
new). The unknown shift between levels of ortho- and para- deuterium was found
by least squares analysis of the , ,
rovibronic levels with odd and even values of . All the energy levels were
obtained relative to the lowest vibro-rotational level (, ) of
the electronic state, and presented in tabular form together
with the standard deviations of the empirical determination. New energy level
values differ significantly from those available in literature.Comment: 46 pages, 9 picture
Spectroscopical diagnostics of molecular microwave plasmas
The paper presents a review of recent results of emission (UV/visible) and absorption (visible and IR) spectroscopical investigations in molecular tube and planar microwave discharges. As a new approach by emission spectroscopy seven band systems of the hydrogen molecule have been analysed to investigate H2 radiative characteristics and to determine the gas temperature completed by Doppler broadening measurements of Hα, Dα and H2 spectral lines. H2 dissociation continuum was used for an estimation of the radiative dissociation rate/degree. By absorption spectroscopy the populations of 4s ArI levels and concentrations of hydrocarbons (e.g. CH3, C2H2, CH4) were determined. In particular, investigations were focused on spatial distributions of plasma parameters.La publication présente un aperçu de nouveaux résultats de mesures de spectroscopie démission (UV/visible) et d'absorption (visible et Infrarouge) dans des décharges microondes moléculaires dans des tubes et en structure plane. La nouveauté consiste en l'analyse de l'émission de système à sept bandes de la molécule d'hydrogène. On étudie ainsi les caractéristiques radiatives de H2 et on détermine la température du gaz par des mesures d'élargissement Doppler des lignes spectrales de Hα, Dα et H2. Le continuum de dissociation de H2 est utilisé pour estimer le degré de dissociation radiative. Les populations des niveaux 4s de l'Ar I et les concentrations des hydrocarbures (par exemple CH3, C2H2, CH4) sont déterminés par spectroscopie d'absorption. En particulier on s'est intéressé à la distribution spatiale des paramètres du plasma
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[no abstract available