Developement of Water Cherenkov Detector for the Giant Air Shower Array(Pierre Auger Project)

皮埃尔·奥格项目将建造两个大型天文台来研究能量超过10^<20>eV的宇宙射线。将在美国犹他州和阿根廷门多萨普罗旺斯分别建造两个3000平方公里的探测器。地表探测器的选择是面积10 m^2，水深1.2 m的水箱。每个阵列将由大约1600辆这样的坦克组成。为了研究如何有效地实现介子电磁分离，在世界上唯一运行的阵列——秋野巨型风淋阵列（AGASA）上部署了两个水箱。1996年秋天安装的第一个储罐的所有表面都覆盖了漫反射器。第二个坦克，在1997年夏天安装，除了顶部是吸收光的黑色外，所有表面都有漫反射器。第二个坦克有一个更快的反应，这可能允许更好的介子电磁分离。目前的研究结果如下：A。横向分布：了解淋浴粒子的横向分布函数（1df）对于确定具有宽间距探测器的表面阵列中的淋浴能量至关重要。因此，我们的目标是从AGASA的水箱中得出一个实验df，并将其与使用非常相似的探测器单元的Haverah Park实验的1df进行比较。结果与Haverah Park实验的预期密度分布一致。b .水切伦科夫探测器（WCD）的自我校准：俄格天文台计划部署3200个探测器站。在VEQ中，每个观测站都配备一个闪烁反望远镜来校准每个探测器的灵敏度是不现实的。我们已经证明了在没有额外设备的情况下校准和监测WCD的能力。c .黑顶和白顶WDC的比较：对标准μ子信号进行了白顶和黑顶WCD的差异研究，并根据模拟结果与预期一致。

The Pierre Auger project will construct two large observatories to study cosmic rays with energies in excess of 10^<20>eV.Two detectors will be built of 3000km^2 each in Utah, USA and Mendoza Provence, Argentina. The choice of the surface detector is a water tank of 10 m^2 area and 1.2 m deep. Each array will consist of about 1600 such tanks. In order to study how effectively we can achieve muon-electromagnetic separation, two water tanks were deployed at the Akeno Giant Air Shower Array (AGASA) which is the only operational array in the world. The first tank, installed in fall of 1996 has all surfaces covered with diffuse reflector. The second tank, installed in summer 1997, has diffuse reflector on all surfaceas except the top which is a light absorbing black. The second tank has a much faster response which may permit better muon-electromagnetic separation. The results so far are as follows :A.Lateral Distribution : Knowledge of the lateral distribution function (1df) of shower particles is crucial in the determination of the shower energy in surface arrays with a wide separation of detectors. Thus we aim to derive an experimental 1df from the tanks at AGASA and compare it to the 1df of the Haverah Park experiment which used very similar detector units. The result is in consistent with the expected density distribution from the Haverah Park experiment.B.Self Caliburation of the Water Cherenkov Detectors (WCD) : The Auger Observatory plans to deploy 3200 detector stations. It is not practical to have a scintillation counter telescope attached to each station to calibrate the sensitivity of each detector in VEQ.we have demonstrated the abaility to calibrate and monitor a WCD without additional equipment.C.Comparison of Black-Top and White-Top WDC's : The differences of the white-top and black-top WCD's have been studied for standard muon signals and agree with expectations based on simulation.