Beta spectrometry applied to environmental radioactivity measurements
P. Bouisset, R. Gurriaran, E. Yerebakanian and A. Courti
Radioprotection 2005, Vol. 40, n° 1, pages 29 à 45
Techniques used to quantify pure beta emitters (3H, 14C, 90Sr, 36Cl, 63Ni...) in environmental matrices are based on a physico-chemistry selection of the element followed by liquid scintillation or proportional counting. We have studied a new method using thin Si (PIPS) detectors to obtain a spectrometric discrimination with or without the physico-chimical discrimination. Detection limits for pure sources are of the same order than values obtained with standard techniques with the advantage to identify other residual radionuclides. The part of natural radionuclide is important for surveillance measurement because global results induce complementary measurements. The spectrometry technique can discriminate natural and artificial contribution without necessity of detailed measurement even results above regular thresholds.