Research On X-ray GEM Detectors

In this thesis,the fabrication and the performance of two kinds of GEM detectors,counting GEM detector and imaging GEM detector,are mainly studied.And the fabrication of closed GEM detector was also discussed.The counting GEM detector was calibrated by DC power.It was found that there were some bad sectors;The causes and solutions of the nonlinear distortion of the detector at the low end and high end are discussed;The photon fluence rate of K fluorescent X ray radiation facility was measured,and using this facility proves that the number of photons measured by the detector increases linearly with the increase of the absolute photon number.To the imaging GEM detector,its flat curve,position resolution and energy resolution are measured.For GEM detector,the best working voltage is 1630 V,and the best position resolution is 677μm and the energy resolution is 30.19%.The paper also measured the facula size of two facilities,the hard X rays calibration facility and the K fluorescent X rays radiation facility by using this detector,the average value of the hard X rays calibration facility’s facula diameter is 9.03 ± 0.68 mm,and the radiation field’s average diameter at 30 cm from the center of the radiator is 11.23±0.31 cm.The experimental results are verified by using CCD detector and matrix detector respectively,and proves the reliability of the detectors.Finally,the paper discuss the necessity and feasibility of the research on the closed GEM detector.By processing the chamber and replacing the internal components,the pollution to the working gas is reduced.Using the designed closed GEM detector measured the cosmic rays,and its results is similar to the flow type GEM detector.