Knowledge Bank

The 0-0 band of the $B\prime \mathrm{<mrow\; data-mjx-texclass="ORD">3</mrow>}\Sigma u-\to B3g\Pi$ system of molecular nitrogen at 1.53 $\mu m$ has been recorded at a resolution of $0.046cm-1$ and a precision of $0.007cm-1$. Although this band system was characterized by early investigators as the Nitrogen Infrared Afterglow System, the 0-0 band, in particular, appears in D.C. glow discharges with an intensity comparable with that of neighboring bands of the First Positive System. Accordingly, it is a prime candidate as an auroral feature, although no band of the B^{\prime} -B has yet been observed in auroral displays. The spectrum was obtained with a 5-meter Jarrell-Ash Czerny-Turner spectrograph adapted to spectrometric operation in the 1 to 2 $\mu m$ wavelength region. The grating is a 10-inch 300 line per mm echelle used in the third order, A lead screw assembly with a stepping motor drive has been installed to translate an exit slit which is focused onto a cooled intrinsic germanium detector. The reciprocal dispersion at the 75 micron scanning exit slit is 1.44 $\backslash AA$ per mm. The result has been the production of very reproducible high resolution spectra. The band has been recorded through a lock-in amplifier onto both magnetic tape and a strip chart recorder with higher order lines of iron and neon as standard wavelengths. A rotational analysis for the 27 branches of the band has been carried out on the basis of 482 identified lines.