Magnetic-field induced N2(B→A) emission from a beam of metastable nitrogen molecules and precise term energy of the N2(A′ 5Σ+g) state

Magnetic field anticrossing measurements have been made in order to identify unambiguously the N2(A′ 5Σ+g) level responsible for the recently observed perturbation of the N2(B 3Πg, v=10, 3Πe2(12)) level [Ch. Ottinger and A. F. Vilesov, J. Chem. Phys. 100, 4862 (1994)]. When a weak magnetic field (H=0–3000 G) was applied across the N2 metastable beam, new field-induced perturbations were observed in B,v=11, which were ascribed to interactions with A′, v=2. This multiple perturbation pattern permits a determination of the relative energy of the A′ and B states with a precision of 0.02 cm−1.