摘要: 介绍了一款小型宇宙射线探测仪。该仪器具有宇宙射线科普演示功能，主要用于实时测量μ子射线并显示计数，以及长时间尺度下（年）稳定地对不同角度的次级宇宙线通量进行监控记录。简要地展示了探测器的硬件构造和探测效率的模拟计算。探测仪单个探测器的探测效率为93.1%，两个探测器符合测量的探测效率为86.6%。根据探测器的计数率以及模拟计算的探测效率，估计了次级宇宙射线垂直地面方向的通量，为J=29±3 m^-2 sr^-1 s^-1。另外，利用该宇宙射线探测仪，测量了兰州市区的次级宇宙射线的天顶角分布。其结果很好地满足I（θ）=IH+I₀ cos^α θ经验公式，其中的角度依赖参数α=2.42±0.52。

A small cosmic ray device is introduced in this paper.It has the demonstration function for popularization of science,and can be used mainly to display the μ counts in a real-time measurement,and to monitor the secondary cosmic ray flux at different angles in a very long time scale (years).We briefly show the hardware of the device and the detecting efficiency calculation by simulation.The detecting efficiency for one detector of the device is 93.1%,and the detecting efficiency is 86.6% for the coincidence measurement of two detectors.Based on the count rate by the detector and the simulated efficiency,the secondary cosmic ray flux perpendicular to the ground surface is measured,which is J=29±3 m^-2sr^-1 s^-1.Moreover,with an application of the device,we measured the angular distribution of the secondary cosmic ray rate in Lanzhou City.The resulting angular distribution agrees well with the empirical formula as I(θ)=IH+I₀ cos^α θ,in which the parameter for the angle-dependence is α=2.42±0.53.