The Development Of Air Shower Core Detector

Human steps for space exploration never stop, the original of cosmic ray as one of the most controversial and mystery subject still be discussed. To study the composition of cosmic ray and energy spectrum will undoubtedly become one of the most attention topics around the world.This experiment site is located in the southwest of China-Tibet province Lhasa town DangXiongXian,4300 miter above the sea level, the corresponding local atmospheric depth is approximately 606 gram per square centimeter, which just in the "knee" area and the maximum development of cosmic atmospheric showers. So it has a unique geographical advantage. YAC-Ⅱhas an advanced data analysis method. It will be cooperate with Extensive Air Shower array and Underground Muon Detector array in the Yangbajing international observatory of cosmic ray. So it can completely record the message of high-energy particles in the "knee" area, and accurate bring about the physical target that the measurement of high-precision single component of original protons and helium nucleus energy spectrum.In the course of experiment, this paper put more emphasis on the development of air shower core detector. Throughout the process of air shower core detector development, YAC-Ⅱdetector belongs to optical-fiber scintillation detector, so first introduce the theory of optical-fiber scintillation detector. Then introduce the structure of YAC-Ⅱdetector, considering the natural and climate environment in Tibet. This group adopted a better way, so that it can photo protection, waterproof, anticorrosion and thermal insulation. In order to make YAC-Ⅱdetector more safety, our group also optimizes the protective covering. Feasibility analyse is used to choose each device in the detector so that these device can meet the requirement of experiment. Based on the solution of feasibility analysis, including the thickness choice of lead, the choice of optical fiber scintillation, photomultiplier tubes and backend electronics choice, magnetic shielding tube choice, performance testing of high-voltage signal and joints, etc. the performance each of these devices will be tested. The result of these tests show that the performance tubs of the YAC-Ⅱdetector is very good and it can meet the anticipated goal.In addition, in order to meet the goal, the correct analysis of whether photomultiplier tubes'measurement range in the detector can attain the target, this group strictly calibrate the sample of detector, using the liner accelerator electron beam of Beijing electron positron collision. This mainly includes the liner dynamic range of two different type photomultipliers (R5325, R4125) and the saturated effect of the scintillations. Experimental results prove that the dynamic range of high-gain photomultiplier R4125 from one electronic to thousands of electronic; while the dynamic range of low-gain photomultiplier R5325 from hundreds of electronic to millions of electronic. These data demonstrate that YAC-Ⅱcan well realize the measurement of dynamic range from 50TeV to 10PeV.In the end of this article, our group analyze observed each physical parameter in experiment of YAC-Ⅱdetector. The high-energy shaft core examples is chosen by the analysis of various physical parameter, the physical parameter observed reflects different information of the original particles. Therefore, can be used to identify elementary particles and realize the physics object of YAC-Ⅱ.