Rydberg series of NO converging to the ionic states b3Π, A1Π, and w3Δ

Rydberg series of NO in the 600–1000-Åregion were investigated by using a 6.65-m high-dispersion vacuum spectrograph. The previous β, γ (v = 0), and γ (v = 1) Rydberg series were extended up to n = 31, 31, and 28, respectively. From the analysis of these Rydberg series, accurate ionization energies were obtained: 133 565 ± 3 (16.5596 eV) for b³Π (v = 0); 147 811 ± 3 (18.3258 eV) for A¹Π (v = 0); 149 372 ± 3 cm^?1 (18.5193 eV) for A¹Π (v = 1) of NO⁺. A new Rydberg series converging to one of the triplet components in b³Π was identified, and the coupling constant of b³Π was estimated to be 35 ± 8 cm^?1. Higher members of two Rydberg series were newly observed in the 700–725-Åregion. From their series limits, 139 926 ± 3 and 141 160 ± 3 cm^?1, they were assigned to be the Rydberg series converging to the v = 3 and 4 levels of ω ³Δ in NO⁺.