Efficiency Calibration Of Silicon Drift Detector(SDD) In Low Energy Region

The accurate detection efficiency of a Silicon Drift Detector is a critical factor for determining X-ray spectrum in low energy region.In this thesis,the detection efficiency calibration of the Silicon Drift Detector(SDD)was determined in the low energy region by two methods.The first method is the relative efficiency calibration method in which we used the ratio of the experimental and theoretical bremsstrahlung spectrum of 19 keV electron beams bombarding a high pure thick carbon(2mm thick)to get the relative detection efficiency curve,the theoretical bremsstrahlung spectrum was calculated using Monte-Carlo computer code PENELOPE,then the absolute values of detection efficiency were determined by normalizing the relative detection efficiency curve to the absolute efficiency values which were measured by using241 Am and57Co standard radioactive sources,In thismethod the self-absorption correction and the convolution of detector's response function with the simulated bremsstrahlung spectrum have simultaneously been taken into account more over the smoothing of the experimental bremsstrahlung has been performed.The second method is a theoretical model based on the geometrical parameters of Silicon Drift Detector.We find the efficiency values calculated by the relative efficiency calibration method were showing good agreement with the efficiency values obtained by the theoretical model method.