An experimental determination of the oscillator strengths for some transitions in the Lyman bands of molecular hydrogen

• Published in: Journal of quantitative spectroscopy & radiative transfer 1968-05, Vol.8 (5), p.1193-1200
• Main Authors: Haddad, G.N., Lokan, K.H., Farmer, A.J.D., Carver, J.H.
• Format: Article
• Language: English
• ISSN: 0022-4073; 1879-1352
• DOI: 10.1016/0022-4073(68)90067-8

The ultraviolet absorption cross-section for molecular hydrogen at room temperature has been measured absolutely at a resolution of 0·3 Å, between 1060 and 1130 Å. This range of wavelengths covers the (0-0) through (3-0) vibrational bands of the B 1 Σ + u ↔ X 1 Σ + g Lyman system. The nature of the curve of growth of an individual line has been investigated in detail, and shown to agree closely with the expected behaviour of a Doppler-broadened, Lorentz line for hydrogen at room temperature. A curve-of-growth analysis has been used to determine absolute line strengths for all observed transitions within each band. For each band, the distribution of line strengths is in accordance with the expected weighted Boltzmann distribution of initial states at room temperature, with most of the observed absorption concentrated in the R 0, R 1 and P 1 transitions. Oscillator strengths for these bands have been derived from the integrated band intensities, and confirm, within the limits of the experimental errors, the theoretical Franck-Condon factors.