Spectra for Gaseous Halogens with the dc Arc and Inert Gas Shields

Abstract

The spectra for the halogens were excited in a Stallwood jet using a dc arc between 1% thoriated tungsten electrodes. The shield gases were helium, 50% argon-50% helium, and argon. In helium, only atomic lines of fluorine were excited, some singly ionized lines of chlorine were excited, and the atomic lines of iodine were weak. Atomic lines of fluorine were faintly visible in argon while the atomic lines of chlorine, bromine, and iodine showed an increasing intensity in 50% argon-50% helium, and argon, respectively.