Fifield, L KeithSynal, HSuter, M2015-12-130168-583Xhttp://hdl.handle.net/1885/77910Ultra-sensitive detection by accelerator mass spectrometry of the long-lived plutonium isotopes, 239,240,242,244Pu, has been demonstrated at an accelerating voltage of 300 kV. Transmission efficiencies as high as 15% have been observed for Th3+ ions. Using a gas ionisation detector with an ultra-thin silicon nitride window, an energy resolution sufficient to separate Pu3+ ions from interfering Dy2+ ions with 2/3 of the energy was possible. Sensitivities approaching 10 6 atoms for the various Pu isotopes were achieved.Keywords: Actinides; Chemical analysis; Demodulation; Electric potential; Ions; Mass spectrometry; Particle accelerators; Radioisotopes; Sensitivity analysis; Silicon nitride; Accelerating voltage; Accelerator mass spectrometry (AMS); Silicon detectors; Trace detec Accelerator mass spectrometry (AMS); Actinides; Plutonium; Trace detection200410.1016/j.nimb.2004.04.1482015-12-11