A NEW BAND SYSTEM OF NITROGEN - OBSERVATION OF THE N2(G(3)DELTA(G)-]W(3)DELTA(U)) TRANSITION

The first experimental observation of the N2(G3DELTA(g) --> W3DELTA(u)) transition is reported On here. The emission forms part of the spertrum of the so-called N2 beam afterglow, a spontaneous luminescence emitted by a molecular beam of N2 issuing from an intense d.c. discharge. Using a high performance charge-coupled device (CCD) optical multichannel detector, 18 bands of a new band system were observed with 2 angstrom full width at half-maximum (FWHM) resolution in the 350-650 nm region. Three well-resolved nu'' progressions were analyzed. From a comparison with the known vibrational spacings in the N2(G) and N2(W) states, they could be assigned unambiguously to the N2(G --> W) transition. This observation allows the energy of the N2(G) state to be determined as T(e) = 89 505 cm-1 or 11.10 eV, thereby also fixing the location of the previously observed H(3PHI(u)) state at T(e) = 107 328 cm-1 or 13.31 eV.