OBSERVATION OF NO B 2-PI(V = 3)[-X 2-PI(V = 0) ABSORPTIONS WITH 1+1 MULTIPHOTON IONIZATION - PRECISION LINE-POSITION MEASUREMENTS AND PARITY ASSIGNMENT OF THE B 2-PI STATE

Absorptions are observed in the beta(3,0) band of NO, B2PI(nu=3) <-- X2PI(nu=0) using 1 + 1 multiphoton ionization at photon energies in the range 47 801-48 542 cm-1. Line positions are reported in 10 of the 12 possible branches with an accuracy of 0.05 cm-1, directly traceable to the visible I2 absorption spectrum. LAMBDA doubling in the beta(3,0) band is explicitly resolved, allowing a definitive parity assignment of the B2PI(v=3) rotational levels. Accurate term energies and molecular constants are presented for B2PI(v=3). Comparison with previous measurements reveals significant discrepancies. Line positions are also reported in the gamma(2,0) band, A2SIGMA+(v=2) <-- X2PI(v=0), of the (NO)-N-14-O-18 and (NO)-N-15-O-16 isotopes.