CW HI laser based on a stationary inverted lyman population formed from incandescently heated hydrogen gas with certain group I catalysts

Abstract

Each of the ionization of Rb/sup +/ and cesium and an electron transfer between two K/sup +/ ions (K/sup +//K/sup +/) provide a reaction with a net enthalpy of an integer multiple of the potential energy of atomic hydrogen, 27.2 eV. The corresponding Group I nitrates provide these reactants as volatilized ions directly or as atoms by undergoing decomposition or reduction to the corresponding metal. The presence of each of the reactants identified as providing an enthalpy of reaction of an integer of that of the potential energy of atomic hydrogen (m/spl middot/27.2 eV) formed a low applied temperature, extremely low-voltage plasma called a resonance transfer (RT)-plasma having strong vacuum ultraviolet (VUV) emission. In contrast, magnesium and aluminum atoms or ions do not ionize at integer multiples of the potential energy of atomic hydrogen. Mg(NO/sub 3/)/sub 2/ or Al(NO/sub 3/)/sub 3/ did not form a plasma and caused no emission. For further characterization, we recorded the width of the 6563 /spl Aring/ Balmer /spl alpha/ line on light emitted from RT-plasmas. Significant line broadening of 18, 12, and 12 eV was observed from an RT-plasma of hydrogen with KNO/sub 3/, RbNO/sub 3/, and CsNO/sub 3/, respectively, compared to 3 eV from a hydrogen microwave plasma. These results could not be explained by Stark or thermal broadening or electric field acceleration of charged species since the measured field of the incandescent heater was extremely weak, 1 V/cm, corresponding to a broadening of much less than 1 eV. Rather the source of the excessive line broadening is consistent with that of the observed VUV emission, an energetic reaction caused by a resonance energy transfer between hydrogen atoms and K/sup +//K/sup +/, Rb/sup +/, and cesium, which serve as catalysts. KNO/sub 3/ and RbNO/sub 3/ formed the most intense plasma. Remarkably, a stationary inverted Lyman population was observed in the case of an RT-plasma formed with potassium and rubidium catalysts. These catalytic reactions may pump a continuous wave HI laser as predicted by laser equations and a collisional radiative model used to determine that the observed overpopulation was above threshold.