The possibility of the use of intensity distributions in the rotational structure of the GK 1Σ+ g, v′ → B 1Σ+ u, v″ of H2 for determining the gas temperature of a nonequilibrium plasma was studied. For this purpose, the intensities of lines in the R- and P branches of the 0-0, 0-1, 0-2, and 0-3 bands were measured for the first time in a hydrogen plasma of a capillary arc discharge at a pressure of 6 torr for a current density in the range of 0.64-9.5 A/cm2 (previous measurements were made only for the lines of the R branch of the 0-0 band). It was found that the use of Hönl-London factors as the line strengths resulted in significant differences in the populations of levels found from the intensities of lines of the R and P branches; in the rotational temperatures determined from different branches and different bands; in the rotational temperatures of the GK 1Σ+ g, v′ = 0 vibronic state and the gas temperature obtained from the intensity distribution in the rotational structure of the Fulher's α system and from the Doppler broadening of spectral lines of atoms and hydrogen molecules. It is shown that the equality of rotational [determined from the R branch of the 0-0 band] and gas temperatures is likely to be an accident, and that the use of intensities in the rotational structure in the system of GK 1Σ+ g → B 1Σ+ g bands for diagnostics of plasma requires data on the dependences of transition probabilities on rotational quantum numbers.
|Number of pages||9|
|Journal||Optics and Spectroscopy (English translation of Optika i Spektroskopiya)|
|State||Published - 1 Aug 1999|
Scopus subject areas
- Atomic and Molecular Physics, and Optics