Performance of catalytically condensed carbon for use in accelerator mass spectrometry

Abstract

Two catalytic processes have been explored for the preparation of suitable samples for use in 14C measurements on an accelerator mass spectrometer. A heavy hydrocarbon was condensed from C2H2 using AlBr3 as a catalyst. This process had low isotopic fractionation, and the carbon ion beam obtainable was 60-70% that from graphite. In the second process, iron powder was used to produce graphite directly from CO2 and H2 at 600 °C. A sample preparation system using this reaction has been built. The carbon product produces exceptionally intense, long-lived ion beams. The process introduces little 14C background, and has no observed memory effects. © 1984.