Actinides isotopic analysis using a 1 MV AMS system

Abstract

The VEGA 1 MV AMS system at ANSTO has been custom-designed to cover analysis of a wide range of long-lived radioisotopes, including routine radiocarbon analysis and multiple-isotope analysis of actinides. The system incorporates 1.0 m radius injection and analysing magnets with o -axis cups on high and low mass sides. Following the analysing magnet, rare isotope beams pass through a 1m radius spherical electrostatic analyser and a 120 1 m radius magnet. The detector station consists of a two-anode gas detector, with o -axis options to direct isotopes to either a Faraday cup or an electron multiplier ion counter. All three analysing magnets are fitted with electrostatic bouncer systems. At the LE end, the bouncer works in the usual way for all isotope combinations of interest, including 12C-13C-14C and actinides. The HE bouncers are used to transmit a range of masses of interest for actinides analysis, for example mass 239 to 244 Pu isotopes. For uranium analysis, the less rare isotopes can be directed to o axis cups or the ion counter. Software has been implemented to enable a high degree of exibility in analysing up to 8 isotopes at a time. In this paper we present details of the system and its performance and applications. © The Author