Knowledge Bank

The KrCl laser spectrum recorded on the third order of a 6.65m concave grating spectrograph shows more than thirty absorption lines in the region 2216 - 2224A. The laser was made by ourselves with particular caution against impurity contamination. As was expected from our previous $work1,2$, many absorption lines were assigned to rotational lines of the several $O2$ Schumann-Runge bands appeared as absorption. Some stronger lines were assigned to rotational lines of the O-14 and O-13 bands of HCl V-X system based on the wavenumbers observed by Jaques and $Barrow3$. Spontaneous emission spectra obtained with quartz prism spectrographs show eleven peaks of the B-X system, two continua probably arising from the C-X and B-A transitions in the region 2220-2085A, around 1987A and 2320-2490A, respectively. A continuum observed around 2570A was identified as the V-A system of HCl, since it appeared even when the discharging gas consists of He and HCl only. For the laser or spontaneous emission of KrCl the gas consists of HCl/Kr/He = 0.4/20/79.6, where impurities of HCl, Kr and He are stated to be 99.9, 99.995 and 99.9999%, respectively. The maximum total pressure investigated was 1600 Torr. At this pressure the laser power about 10 mJ/pulse was obtained when the carrier gas He(79.6%) was replaced by a mixture, He(39.6%) and Ne(40%), though this replacement made no change in the laser spectrum. Experimental results when HCl was replaced by $Cl2$ will be presented.