宇宙射线望远镜

宇宙射线望远镜-基本介绍   
宇宙射线望远镜示意图宇宙射线远镜主要是由三件探测器、一组触发电路、一个全球定位系统接收器和一部配备计时器介面的电脑组成。
The Cosmic Ray Telescope contains 3 detectors, a trigger electronics, a GPS receiver and a timer card in a computer.

每件探测器是由一块塑胶闪烁器、一条波长变换器和一个光电倍增管组成，并加以密封。密封可避免环境光线影响光电倍增管。每当宇宙射线粒子穿透塑胶闪烁器时，闪烁器内的有机掺杂物便会受激发而放出蓝光及紫外光。光讯号经波长变换器转换为波长较长的黄绿光，并导向光电倍增管。光电倍增管将光讯号转为电讯号，并放大输出至触发电路。
Every light-proof detector consists of a plastic scintillator, a wavelength shifter and a photomultiplier (PM) tube. When cosmic ray particles pass through the scintillator, the organic doping within is excited and hence emit ultra-violet and bluish light. It is changed to light of longer wavelength (greenish yellow) and guided to the PM tube. The optical signal is transformed and amplified into electrical signal and then transmitted to the trigger electronics.

触发电路是由三个鉴别器和一个「与」门电路组成。鉴别器先将形状不一的类比讯号转换成同样的逻辑讯号，再由「与」门电路决定是否触发数据收集。这样便可除去由环境辐射所产生的大量噪音讯号。
The trigger electronics consists of 3 discriminators and a coincidence unit. A discriminator transforms shapeless signals into identical logic signals. Afterwards the coincidence unit triggers data acquisition. This can reduce lots of background noise due to surrounding radiations.

利用电脑程式，计时器可记录来自触发电路的宇宙射线讯号。同时，由于电脑的内置时钟不够精确，计时器亦会记录来自全球定位系统的报时讯号，以便准确计算宇宙射线的接收时间。
Implementing a computer program, the timer card can record cosmic ray signals from trigger eletronics. As the computer clock is not accurate enough, the timer card also records time beats from Global Positioning System (GPS). This makes accurate timing of cosmic ray arrival feasible.

全球定位系统接收器负责接收来自卫星的讯号。讯号包含该卫星的时间和位置资料；利用不同卫星的资料，可以推算该观测站的准确位置和时间，并将准确的报时讯号传送到计时器。
GPS receiver module get signals from satellites ahead. The signals contain timing and positioning information from the satellites, which can determine the time and the position of the receiver accurately.

宇宙射线望远镜-测量辐射效应   
探测部分测量辐射效应的宇宙射线望远镜（CRaTER：The Cosmic Ray Telescope for the Effects of Radiation）将给出月球辐射环境的特征，确定其对生物可能产生的影响。CRaTER还将对辐射效应和屏蔽模型进行测试，这有助于开发保护技术。