Oscillator strengths and line widths of dipole-allowed transitionsin N 14 2 between 86.0 and 89.7 nm

Oscillator strengths of 23 electric-dipole-allowed bands of N 14 2 in the 86.0-89.7 nm ( 111 480 - 116 280 cm − 1 ) region are reported from synchrotron-based photoabsorption measurements at an instrumental resolution of 6.5 × 10 − 4 nm ( 0.7 cm − 1 ) full width at half maximum. The absorption spectrum comprises transitions to vibrational levels of the c n Π 1 u ( n = 3 , 4 ) , o 3 Π 1 u , and c n + 1 ′ Σ 1 u + ( n = 3 , 4 ) Rydberg states as well as the b Π 1 u and b ′ Σ 1 u + valence states. The J dependences of band f -values derived from the experimental line f -values are reported as polynomials in J ( J + 1 ) and are extrapolated to zero nuclear rotation in order to facilitate comparisons with the results of coupled Schrödinger equation calculations. Many bands in this study are characterized by a strong J dependence of the band f -values and display anomalous P -, Q -, and R -branch intensity patterns. Predissociation line widths are reported for six bands. The experimental f -value and line-width patterns inform current efforts to develop comprehensive spectroscopic models for N 2 that incorporate rotational effects and predissociation mechanisms, and are critical for the construction of realistic atmospheric radiative-transfer models.