ABSOLUTE OPTICAL OSCILLATOR-STRENGTHS FOR DISCRETE AND CONTINUUM PHOTOABSORPTION OF MOLECULAR NITROGEN (11-200 EV)

Absolute optical oscillator strengths for the photoabsorption of molecular nitrogen in the energy region 11-200 eV have been determined using low resolution (1 eV fwhm) dipole (e, e) spectroscopy. The absolute scale was obtained by TRK sum-rule normalization. High resolution (0.048 eV fwhm) dipole (e, e) spectroscopy has been used to measure the absolute optical oscillator strengths for the excitation of molecular nitrogen in the valence shell discrete region. The measurements are free of the `'line saturation'' (bandwidth) effects which complicate direct photoabsorption studies using the Beer-Lambert law. Absolute optical oscillator strengths for excitation to individual vibronic bands of the b 1PI(u) and b' 1SIGMA(u)+ valence excited states, the c 1PI(u), c' 1SIGMA(u)+ and o 1PI(u) Rydberg states and also the e 1PI(u) and e' 1SIGMA(u)+ states have been obtained. The present results are compared with previously published experimental data and theoretical calculations.