STUDY OF POSITION RESOLUTION OF ELECTRIC-SHOWER CALORIMETER USING MULTIANODE PHOTOMULTIPLIER READ OUT.

去年，我们已经构建了一个系统，该系统能够从多阳极光电倍增管获取模拟信号并同时将其转换为数字数据。我们现在可以在这个系统下测试一个多阳极光电倍增管。然而，我们有一个问题，移动光源的位置。通过引入一种能够精确移动多阳极光电倍增管的机器，这一问题得到了解决。我们还介绍了最近开发的蓝色发光二极管（led）。这个led发出的光正好在这个管的敏感波长的中间，使测量可靠。使用该光源，虽然光斑不是一个完美的点，但我们可以在中心区域达到0.4mm的位置分辨率，在距离中心25mm处达到0.6mm左右的位置分辨率。然而，我们在光电倍增管的某个位置发现了一个有趣的行为。我们也在调查这一现象，并询问一家生产这种管子的公司，为什么会发生这种行为。同时，本项目的一个目的是借助多阳极光电倍增管的能力精确测量电磁阵雨的起始位置。从阵雨乞求的光输出预计是非常小的，所以这个管应该足够好，以检测几个光电子在一个事件。我们安装了在电磁淋浴模拟中很有名的egs4，不仅测试了淋浴的外形，还测试了淋浴启动时的波动。并通过多阳极光电倍增管的实验进行了验证。并给出了研究结果。

LAST YEAR WE HAVE CONSTRUCTED A SYSTEM WHICH IS ABLE TO TAKE ANALOG-SIGNALS FROM A MULTIANODE-PHOTOMULTIPLIER AND CONVERT THEM TO DIGITAL DATA SIMUTANEOUSLY.WE NOW CAN TEST A MULTIANODE PHOTOMULTIPLIER TUBE UNDER THIS SYSTEM.HOWEVER WE HAD AN PROBLEM TO MOVE THE POSITION OF THE LIGHT SOURCE.THIS HAS BEEN RESOLVED BY INTRODUCING A MACHINE WHICH IS ABLE TO MOVE THE MULTIANODE PHOTOMULTIPLIER TUBE PRECISELY.WE ALSO INTRODUCED A RECENTLY DEVELOPED BLUE COLORED LIGHT EMITTING DIODE(LED). THE LIGHT EMITTED BY THIS LED IS JUST IN THE MIDDLE OF THE SENSITIVE WAVE LENGTH OF THIS TUBE MAKE THE MEASUREMENT RELIABLE.WITH USING THIS LIGHT SOURCE,ALTHOUGH THE SPOT IS NOT PERFECTLY A POINT,WE COULD REACH A POSITION RESOLUTION OF 0.4MM IN THE CENTER REGION AND ABOUT 0.6MM AT 25MM AWAY FROM THE CENTER.HOWEVER WE FOUND A FUNNY BEHAVIOR AT A CERTAIN POSITION OF THIS PHOTOMULTIPLIER.WE ARE ALSO INVESTIGATING THIS PHENOMENA AND ALSO ASKING A COMPANY WHICH PRODUCED THIS TUBE WHY THIS KIND OF BEHAVIOR HAPPENED.IN THE MEAN TIME,A PURPOSE OF THIS PROJECT WAS TO MEASURE A START POSITION OF A ELECTROMAGETIC SHOWER PRECISELY WITH A HELP OF MULTIANODE PHOTOMULTPLIER TUBE CAPABILITY.LIGHT OUTPUT FROM THE SHOWER BEGGING IS EXPECTED VERY SMALL SO THAT THIS TUBE SHOULD GOOD ENOUGH TO DETECT A FEW PHOTOELECTRONS IN A EVENT.WE HAD INSTALLED EGS4 WHICH IS FAMOUSE IN THE ELECTROMAGNETIC SHOWER SIMULATION AND TESTED NOT ONLY THE SHOWER PROFILE BUT ALSO FLUCTUATIONS FOR THE SHOWER STARTING.THIS IS ALSO TESTED BY AN EXPERIMENTS WITH A MULTIANODE PHOTOMULTIPLIER TUBE.THE RESULTS ARE ALSO PRESENTED.