Ultrasensitive Isotope Trace Analyses with a Magneto-Optical Trap

Abstract
Laser manipulation of neutral atoms has been used to count individual krypton-85 and krypton-81 atoms present in a natural krypton gas sample with isotopic abundances in the range of 10−11and 10−13, respectively. This method of isotope trace analysis is free of contamination from other isotopes and elements and can be applied to several different isotope tracers for a wide range of applications. The demonstrated detection efficiency is 1 × 10−7. System improvements could increase the efficiency by many orders of magnitude.