Model Calculations of Continuous-Wave Laser Ionization of Krypton

摘要

This report describes modeling of a scheme that uses continuous-wave (CW) lasers to ionize selected isotopes of krypton with high isotopic selectivity. The models predict that combining this ionization scheme with mass spectrometric measurement of the resulting ions can be the basis for ultra-sensitive methods to measure (sup 85)Kr in the presence of a 10(sup 11) excess of the stable krypton isotopes. Two experimental setups are considered in this model: the first setup is for krypton as a static gas, the second is for krypton in an atomic beam. In the static gas experiment, for a total krypton press of 10(sup (minus)4) torr and 10 W of power in the cavity, the model predicts a total krypton ion current of 4.6 x 10(sup 8) s(sup (minus)1) and for a (sup 85)Kr/Kr of 10(sup (minus)11) a (sup 85)Kr ion current of 3.5 s(sup (minus)1) or about 10,000 per hour. The atomic beam setup allowed higher isotopic selectivity; the model predicts a (sup 85)Kr ion current of 18 s(sup (minus)1) or 65,000 per hour.