The spectral output of flash-discharge lamps containing iodine, and mixtures of iodine and the inert gases were studied at selected wavelengths and discharge voltages. It was found that addition of xenon or krypton to iodine produced a marked enhancement of the 2062-Å iodine line compared to the output from a pure iodine discharge. The enhancement of this line was found to be a maximum at approximately 130 torr and 3.0-kV discharge voltage with either of the inert gases. An enhancement factor of about 400 was found with added xenon and about 700 for a lamp filling containing krypton. It was postulated that, with xenon, energy-transfer collisions between metastable xenon and ground-state iodine atoms were responsible for the enhanced 2062-Å radiation. With krypton—iodine mixtures an additional mechanism for producing excited iodine atoms was the reaction of metastable krypton atoms with iodine molecules producing one ground-state iodine atom and one in the 6p4P3/2 state.
ALGIRD G. LEIGA and JOHN A. MCINALLY, "Enhancement of the 2062-Å Atomic-Iodine Line in an Iodine Inert-Gas Flashlamp," J. Opt. Soc. Am. 57, 317-322 (1967)