The Newly Upgrade Of AS_γ Experiment Ground-based Array-Simulation Research Of Scintillator Detector Unit And Prototype

Since the Austrian physicist Victor Hess by using the balloon-flight experiment opened the prelude of the cosmic rays in1912, the cosmic ray has been studied for more than100years. Based on the researches of the cosmic ray, many new particles (such as positrons, muon, pion, kaon, etc) and their interactions were discovered. In recent years, the cosmic ray is still an indispensable method of studying neutrino oscillation and searching for dark matter particles directly or indirectly.YBJ International ASγ Cosmic Ray Observatory by Sino-Japan cooperation is located in Yangbajing, Lhasa, Tibet, which is about4300meters above sea level, and it is very suitable to carry out the research of gamma-ray sources at the energy region from sub-TeV to several multi-PeV. The experiment was built in1990and has been running stably until now. To further improve the sensitivity of detecting100TeV gamma-ray, we are going to plan to add160surface detectors to optimize the array, whose effective area of72900square meters can be achieved. So in the aspect of detecting the gamma source at the energy region of100TeV, the sensitivity of the improved array is two times of the previous one. We call this work the extension of surface array.This thesis mainly studies the performance of Huairou scintillator detector unit and Yang-bajing ASγ surface extension array scintillator prototype, based on the Geant4simulation pro-gram. In the simulation, we used the surface optical parameters and the reflectivity of Tyvek, the quantum efficiency of photomultiplier tube (PMT) and so on, and by the comparison of the simulation results with the experimental data of Huairou scintillation detector unit, we deter-mined the optical parameters on the surface of scintillator. At the same time, by combining with the influence that the height of the light guide box on the photon number, time resolution and uniformity of position, we preliminary provided optimization scheme of Yangbajing ASγ surface extension array scintillator prototype. Moreover, the performance of the scintillator prototype is tested by prototype scintillator test system built in the laboratory and the experi-mental results have confirmed the reliability of the simulation program, and all the results offer important guiding significance in studying Yangbajing ASγ surface extension array scintillator detector in the future.