Uranium analysis by K X-rays from geological samples

Uranium analysis at trace levels from geological samples was performed by K X-ray fluorescence using a semiconductor detector and radioisotope excitation. The exciting⁵⁷Co-source was constructed in such a way as to produce a high peak to background ratio. Using 10 minutes counting times the detection limit with a 0.26 GBq source was 24 μg/g improving to about 9 μg/g with a ten times stronger source. The detection limits for tin, cerium, tungsten and thorium were also measured.