THE MEINEL SYSTEM (A(2)PI(I)-X(2)SIGMA(-14(2)+, (NN+)-N-14-N-15, AND N-15(2)+()) OF N)

The Meinel system A2PI(u,i)-X2SIGMA(g)+ of the nitrogen molecular ion has been excited in a low-pressure discharge, and the emission spectru m has been investigated between 6000 and 13,000 cm-1 at high resolutio n with a Fourier transform spectrometer. Several bands of N-14(2)+ and N-15(2)+ corresponding to the levels v = 0, 1, 2 in the lower state a nd v = 0, 1, 2, 3 in the upper state and (0-0) band of the mixed isoto pomer have been recorded. The bands (0-2) for N-14(2)+, (0-0) for N-14 N-15, and (0-0), (0-1), (1-2), (1-0), (2-1), (2-0), and (3-1) for N-15 (2)+ are observed and analyzed for the first time, and a global adjust ment of the data is carried out for each isotopomer. Rotational consta nts and molecular equilibrium parameters for the X2SIGMA+ and A2PI sta tes, and isotope shifts are derived. The set of rotational constants o btained permits the wavenumbers of about 1400 observed lines to be rec alculated to within 0.006 cm-1. Physical signification of some effecti ve parameters is