Calculation and interpretation of the continuum radiation of hydrogen molecules
Calculations of hydrogen molecular continuum have been carried out in the wavelength range 120-600 nm, based on potential curves and reduced masses. They give transistion probabilities, lifetimes and spectral intensities as a function of vibrational level population in the upper state. Absolute radiation measurements in H(2)/He and D(2)/He low-pressure ECR plasmas in the wavelength range170-300 nm are compared with results from these calculations. Using the Franck-Condon principle and the corona model for excitation, the relative vibrational population in the upper state is correlated with the population in the ground state, characterized by the vibrational temperature T(vib). The absolute intensities depend on the electron temperature T(e) via the electron excitation rate coefficients. Therefore, the shape of the continuum radiation reflects T(vib), and the absolute value is a function of T(e). The results are in good agreement with those from other spectroscopic techniques in the visible spectral range. This demonstrates that emission spectroscopy of the continuum radiation of H(2) and D(2) is a good tool for diagnostics of low-pressure plasmas. The calculations have also been carried out for other hydrogen isotopes - T(2), HD, DT.
Bibliographic Reference: Article: New Journal of Physics Vol. 2 (2000) pp. 7.1-7.15
Availability: New Journal of Physics
Record Number: 200012067 / Last updated on: 2000-06-21
Original language: en
Available languages: en