arXiv:physics/0310045 · Physical Review Letters
Counting Individual Ca41 Atoms with a Magneto-Optical Trap
Iain D. Moore, K. Bailey, J. P. Greene, Zheng‐Tian Lu, P. Müller, Thomas P. O’Connor, Ch. Geppert, K. Wendt, Linda Young
Abstract
Atom trap trace analysis, a novel method based upon laser trapping and cooling, is used to count individual atoms of $^{41}\mathrm{Ca}$ present in biomedical samples with isotopic abundance levels between ${10}^{\ensuremath{-}8}$ and ${10}^{\ensuremath{-}10}$. The method is calibrated against resonance ionization mass spectrometry, demonstrating good agreement between the two methods. The present system has a counting efficiency of $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}$. Within 1 h of observation time, its $3\mathrm{\text{\ensuremath{-}}}\ensuremath{\sigma}$ detection limit on the isotopic abundance of $^{41}\mathrm{Ca}$ reaches $4.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$.