Abstract
Introduction: In the framework of this thesis, experiments were done to make precise measurements of X-rays using Fast Readout Charge-Coupled Device (pnCCD).
Aim:
This study has been done to characterize the radiation emitted by the primary & secondary X-ray source of the apparatus. As a part of this experiment, it is necessary to measure the emission spectra of the X-ray tube itself and then the emission spectra of the manganese fluorescence X-rays excited by that radiation, eg, in manganese dioxide (MnO2).
Method:
Two cases were considered here during the experiments. Case 1: Measurement of X-rays emitted from the X-ray tube itself. In this case highly accelerated electrons hit the anode material and resultant X-rays are detected by the detector. Case 2: Measurement of fluorescence X-rays from the secondary target (MnO2). In this case, Xrays are emitted by the secondary source where the characteristic fluorescence radiation of manganese (Mn) is excited by means of X-ray tube.
Result:
In the 1st case many chemical elements have been observed in the spectrum. These are the elements of X-ray tube and its surrounding materials. By using the energy calibration, the elements have been clearly identified. In the 2nd case, a clean Mn spectrum has been measured. The secondary target is surrounded by the aluminum foils that shield the X-rays from other elements, thus decreasing the background.
Conclusion:
In all the cases, the degree of illumination of the pnCCD is kept below 2% not to distort the intensity determination by applying aluminum filters of suitable thickness. The intensity of the K X-rays emitted from the secondary target is about 0.06% compared to the total intensity of the direct emission spectrum of the X-ray tube for 25 keV.