Initial Results with Low Energy Single Stage AMS

The National Electrostatics Corporation has built and tested a prototype low energy, open-air, single stage carbon accelerator mass spectrometry (AMS) system (patent pending). The configuration tested has a standard 40-sample, multi-cathode SNICS source on a 300-kV deck. The beam is mass analyzed before acceleration to a gas stripper located at ground. The 14C+ ions are separated from 13C+ and 12C+ arising from the molecular breakup by a 90° analyzing magnet immediately after the gas stripper which acts as a molecular dissociator. The 14C+ beam passes through an electrostatic spherical analyzer before entering the particle detector. The observed 14C/12C precision is better than 5% with a sensitivity of better than 0.05 dpm/gmC. A first single stage AMS system has been ordered. The configuration of this system will be discussed.