An Unique Application of Pnccd X-Ray Detector in Material Characterization

Abstract

In the current work, the principle focus is to analyze the measurements of X-rays by the application of Fast Readout Charge-Coupled Device (pnCCD), which is a special form of CCD developed for the purpose of spectroscopy & imaging of X-radiation with high time resolution. As a part of this work, two phases are taken into consideration. In the first phase, highly accelerated electrons induced by high voltage are collided with a metal target (anode material-Mo in this case) in X-ray tube and emitted X-rays from the tube are measured by pnCCD. In this phase, the X-ray spectrum depends on the anode material and accelerating voltage. During the phase 1 experiment, various elements are noticed in the X-ray spectra, which are originated from the experimental apparatus (X-ray tube only) and its surrounding materials. Through proper energy calibration technique, elemental composition of the materials have been determined. In the second phase, fluorescence X-radiation (secondary radiation), emitted by the secondary target source (MnO2) is measured by pnCCD where, Mn is excited by being bombarded with high energy X-rays from X-ray tube. It is to be noted that MnO2 source is guarded by pure Al sheet foil that protects X-rays from other materials. That is why background radiation is decreased and as a result, clean Mn spectrum is observed. To avoid distortion of the intensity determination, the detector’s degree of illumination is maintained less than 2% in both phases by using Al filters with required thickness. In terms of intensity, it can be concluded that the intensity of K X-rays released from MnO2 source is approximately 0.06% in compare to the total intensity of direct emission spectra from experimental apparatus (X-ray tube) for 25 keV.