Emission spectra of alkali-metal molecules observed with a heat-pipe discharge tube

Intense molecular emission spectra from vapors of each of the alkali metals with the exception of lithium have been observed using a new device, the heat-pipe discharge tube. For Nao, K2, and Br2 the total emission appears to be almost entirely comprised of transitions 1∑u+→1∑ 0+ from the first excited singlet state. For Csa, emission from a low-lying 3∏a state appears to contribute as well.