Knowledge Bank

Each of the fundamental vibration bands of $N2H+$ has been previously $observed1-4$ as well as the first hot $band4v1+v2+v1$. In this paper we report the observation of a very dense spectrum in the infrared region between $3240-3120cm-1$ corresponding to hot bands in each vibrational mode $(2v1+v1,v1+v3,v3$ and $v1+nv2+nv2(n=2,3)$. The spectrum was taken using our difference frequency spectrometer with the velocity modulation technique for detection. N2H was produced in a liquid-nitrogen cooled AC glow discharge with a mixture of 60 torr $N2$. 120 mtorr $H2$ and 7 torr He. The intensity of the lines had only a slight dependence on the amounts of N2 and H2+ whereas the hot bands decrease dramatically with the exclusion of He. Discussion of the vibrational and rotational temperatures will also be presented.