A new graphitization setup for radiocarbon dating using accelerator mass spectrometer at Physical Research Laboratory Ahmedabad

Abstract

A new vacuum system for radiocarbon (14C) dating has been developed at the Physical Research Laboratory (PRL), Ahmedabad. This system uses zinc as a reducing agent and iron powder as a catalyst to convert CO2 into graphite, which is then analyzed using Accelerator Mass Spectrometry (AMS) for measuring 14C content. The system efficiently processes CO2 from wide range of samples including organic material, carbonates and water. In this paper, we discuss the details of the setup, graphite reduction efficiency, background activity, and measurements of oxalic acid standards alongside 14C determinations from known international standards. Additionally, the paper outlines the data reduction process for AMS and the procedure for reporting radiocarbon content with uncertainties. The system can handle five samples at a time, with CO2 reduction efficiency ranging from 50 to 100%. Multiple 14C age measurements from 12 international standards highlight the system’s precision and reliability.