Visible chemiluminescence from supersonic mixing metal-oxidant flames

Intense visible chemiluminescence has been produced by injecting oxidants into a supersonic flow of metal vapor in an argon gas carrier. The metals aluminum, boron, barium, carbon, copper, magnesium, silicon, strontium, titanium, uranium, tungsten, and zirconium have been reacted with one or more of the oxidants oxygen, nitrous oxide, chlorine, and fluorine. A spectral survey is summarized herein and representative spectra are presented and discussed. The powder shock tunnel apparatus developed for these studies is briefly described. We emphasize its unique suitability to visible chemical laser studies as its high active species density enhances the available gain and the high flow velocity aids by sweeping the cavity of poisoning deexcited species.