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

Detection of heavy elements by accelerator mass spectrometry with the elect ron 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 ensu res the elimination of molecular ions at the source stage, a highly attract ive feature for any mass-spectrometric use not exploited so far; (ii) the l inear acceleration based on velocity matching and the beam transport system act as a powerful mass filter for background suppression. We have shown th at our system reaches an abundance sensitivity of 1 x 10(-14) for Pb isotop es. 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 Scie nce B.V. All rights reserved.