Vacuum UV monochromator calibration by means of the branching ratio method

The use of the branching ratio method for measurement of relative spectral response in the l100-1650 A wavelength range of a vacuum UV monochromator is described. Relative intensity measurements of rotational lines originating from common upper vibrational-rotational levels of Werner (C1 Π4→ x1 Σg+) and Lyman (B1 Σ4+ → x1 Σ +g) systems of H2, have been made. Selective enhancement of p(2) lines of Lyman system by excitation transfer from Ar was utilized in the intensity measurements. The intensity ratio of N(I) 1131 and 1164 A multiplets has been used to put in the same relative scale Werner and Lyman measurements in H2. (author)