Ion-optics calculations and preliminary precision estimates of the gas-capable ion source for the 1-MV LLNL BioAMS spectrometer

Ion-optics calculations were performed for a new ion source and injection beam line. This source, which can accept both solid and gaseous targets, will be installed onto the 1-MV BioAMS spectrometer at the Center for Accelerator Mass Spectrometry, located at Lawrence Livermore National Laboratory and will augment the current LLNL cesium-sputter solid sample ion source. The ion source and its associated injection beam line were designed to allow direct quantification of C-14/(12) C and H-3/H-1 isotope ratios from both solid and gaseous targets without the need for isotope switching. Once installed, this source will enable the direct linking of a nanoflow LC system to the spectrometer to provide for high-throughput LC-AMS quantitation from a continuous flow. Calculations show that, for small samples, the sensitivity of the gas-accepting ion source could be precision limited but zeptomole quantitation should be feasible. (c) 2007 Elsevier B.V. All rights reserved.