Analytical and experimental study of the effect of noise background on the radioactivity measurement

In this experimental work, the instruments used (detector, calibrating sources) has been calibrating, the calibration line of the detector deduced and it has been finding that the equation of calibration line takes the form: The resolution power R has been studying as function of the distance between the activity source and detector; the results obtained show that R decrease by increase the energy of the lines spectrum, this mean that the detector resolution power become bigger. It has been measured the LC، LD and MDA using two different methods of background radiation value, trapezium method and classical method, for two different distances between radioactivity source and detector: (9,3cm) and (10cm). The results show: 1- There is similar comportment of the LC، LD and MDA in function energy and the distance between radioactivity source and detector. 2- The trapezium method gives better results from the classical method to the radiation background, and this leads to lesser MDA value, this means that the sensibility is bigger to measure this quantity. 3- The relative error using MDA is (5%) for large values, and (10%) for small values

Analytical and experimental study of the mechanisms of computing and measuring the radioactivity of the radioactive sources

In this work, we have used the basic techniques for measuring gamma rays. It is based on the use of a sodium iodide (NaI) detector withthallium activated (Tl). We have obtained:  The detector calibration NaI(Tl) and the resolution of the spectrometer.  Measuring and determining the activity of a source can be doneby using the relative, and the absolute method. The results obtained show bythe Comparison between the experimental and the theoretical(of the sources activities)a good agreement, and the best values obtained by the absolute method.