Determination of gas temperature of a nonequilibrium plasma from the intensity distribution in the rotational structure of the GK (1)Sigma(+)(g) -> B(1)Sigma(+)(u) bands of H-2

The possibility of the use of intensity distributions in the rotational str ucture of the GK(1)Sigma(g)(+), v' --> B(1)Sigma(u)(+), v " of H-2 for dete rmining the gas temperature of a nonequilibrium plasma was studied. For thi s purpose, the intensities of lines in the R- and P branches of the 0-0, 0- 1, 0-2, acid 0-3 bands were measured for the first time in a hydrogen plasm a of a capillary are discharge at a pressure of 6 torr for a current densit y in the range of 0.64-9.5 A/cm(2) (previous measurements were made only fo r the lines of the R branch of the 0-0 band). It was found that the use of Honl-London factors as the line strengths resulted in significant differenc es in the populations of levels found ii om 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(1)S igma(g)(+), v' = 0 vibronic state and the gas temperature obtained from the intensity distribution in the rotational structure of the Fulher's alpha s ystem and from the Doppler broadening of spectral lines of atoms and hydrog en 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 accid ent, and that the use of intensities in the rotational structure in the sys tem of GK(1)Sigma(g)(+) --> B(1)Sigma(u)(+) bands for diagnostics of plasma requires data on the dependences of transition probabilities on rotational quantum numbers.