T01_P10

HVE design of a gas interface for routine ¹⁴C sample AMS measurement

Scognamiglio G¹,  Klein M¹, Stolz A², Mous D¹

¹High Voltage Engineering Europa B.V., Amersfoort, Netherlands, ²Institute of Nuclear Physics, University of Cologne, Cologne, Germany

The ¹⁴C AMS measurement of CO₂ gas samples has two main advantages compared to solid: (i) the time-consuming graphitization process is not required and (ii) small sample masses are sufficient for the measurement (below 150 µg carbon), while graphitized samples need few mg carbon. These advantages make the AMS measurement of gas samples a recognized tool in both biomedical and dating applications.

The gas measurement requires a gas interface between the CO₂ source and the AMS system that collects, dilutes with helium and transfers the sample gas with a specific flow and timing.

In this contribution, we present the HVE design of a gas interface for the measurement of carbon samples combusted in an elemental analyzer. The CO₂ resulting from the combustion is collected in a zeolite trap and then transferred to a motor-driven syringe, which ensures the gas transfer to the AMS ion source in a controlled manner. The dead time is minimized by the implementation of two syringes and two zeolite traps. The gas interface is fully automated and can handle sample masses down to a few µg carbon. In combination with the elemental analyzer and the AMS, it supports a throughput of more than 10 samples per hour.