Development of Ion Detector Based on Low-Pressure Time Projection Chamber for Accelerator Mass Spectrometry

A new ion identification method for accelerator mass spectrometry on the basis of measuring ion track ranges is proposed. A low pressure time projection chamber (TPC) with charge readout by means of a thick gas electron multiplier (THGEM) was developed for testing this method. Tracks of alpha particles from various radioactive sources were successfully recorded by this TPC. In particular, their track ranges were measured to a high precision of about 2 $$\%$$ . A simulation was performed, and it was shown that track range measurements would permit efficiently separating isobaric boron and beryllium ions (at a level of ten standard deviations). It is expected that this method will be used in the accelerator mass spectrometry facility in Novosibirsk for dating geological objects—in particular, for the geochronology of Cenozoic era.