AMS of heavy elements with an ECR ion source and the ATLAS linear accelerator

Detection of heavy elements by accelerator mass spectrometry with the electron cyclotron resonance ion source, Argonne linear accelerator and fragment mass analyzer (ECRIS-ATLAS-FMA) system has been developed. The use of the ECR-ATLAS system for AMS of heavy elements has two interesting features: (i) the efficient production of high-charge state ions in the ECR source ensures the elimination of molecular ions at the source stage, a highly attractive feature for any mass-spectrometric use not exploited so far; (ii) the linear acceleration based on velocity matching and the beam transport system act as a powerful mass filter for background suppression. We have shown that our system reaches an abundance sensitivity of 1 x 10(-14) for Pb isotopes. The U-236 detection sensitivity is U-236/U greater than or similar to 1 x 10(-12), limited mainly by the ion source output. (C) 2000 Elsevier Science B.V. All rights reserved.