Estimation of uranium concentration in Indian monazite samples by using HPGe semiconductor detector

Various techniques are available for the estimation of uranium concentration in geological rock samples. In the uranium exploration program in India, the beta-gamma technique is widely used by the Atomic Minerals Directorate for Exploration and Research (Department of Atomic Energy) to estimate uranium concentration in natural rock or soil samples. Uranium concentration cannot be estimated accurately by the beta-gamma technique if the sample has high concentrations of thorium. Because the ratio of thorium to uranium concentration varies between 15 and 30 in monazite samples, uranium concentration in monazite samples cannot be estimated accurately by the conventional beta-gamma technique. Uranium concentration in monazite samples can be estimated by measuring the 1.001 MeV gamma ray peak of Pa-234 (which is a decay product of uranium having a half-life of 1.17 min) using a P-type HPGe semiconductor detector. In this paper, uranium concentrations in 10 samples of Indian monazites were estimated using the P-type HPGe semiconductor detector, in which the average thorium concentration was 9.5%.