CAVITY RING DOWN MEASUREMENT OF THE (1,0)-B-(2)SIGMA(-X (2)SIGMA(+)(G) ABSORPTION-BAND OF THE N-2(+) CATION()(U))

The ultraviolet (1, 0) B (2)Sigma(u)(+) X (2)Sigma(g)(+) transition in the N-2(+) cation was measured with the absorption cavity ring down t echnique. The N-2(+) cations were produced in a stationary DC discharg e in nitrogen under reduced (approximate to 0.5 Tr) pressure. The weak band due to the (4, 0) A (IIu)-I-2-X (2)Sigma(g)(+) transition in the red part of the spectrum was also recorded. Several of the observed t ransitions correspond to absorptions from the vibrationally excited (n u' = 1) states of N-2(+) and to absorptions from the neutral N-2 molec ules in the triplet state.