Summary

The accelerator-based thermal-neutron activation analysis setup at KFUPM has an adequate thermal-neutron flux that can be advantageously used for the elemental analysis of a variety of samples including archaeological ones. The thermal neutrons are derived from the moderation of fast neutrons from the D(d,n)He-3 reaction which produces fast 2.5 MeV neutrons. A maximum thermal flux of about 2.5 x 10(6) n/cm(2)-s was achieved. For the purpose of determining the suitability of the setup for the analysis of contemporary and ancient coins, we carried out a feasibility study by irradiating a selected number of Saudi Arabian coins dating from 1958 to 1987 in the thermal-neutron flux. The induced gamma-ray activities were then counted using a HP-GMX detector coupled to a PC-based data acquisition and analysis system. The elements that were determined in the coins were copper (around 75 %), nickel (around 25%), and manganese (< 0.5 %). Calibration curves were also established for these elements. The determined concentrations are in agreement with the data published b