一种CCD反符合探测器的研究

发布时间：2018-03-30 07:32

本文选题：反符合　切入点：探测器　出处：《云南大学》2015年硕士论文

【摘要】：硬X射线调制望远镜(HXMT)是以直接解调成像方法为基础进行研制的宽波段巡天望远镜。HXMT卫星在轨工作时会有大量带电粒子穿过主探测器,并在其上面沉积能量,产生很多本底事例,严重降低主探测器的探测灵敏度。CCD探测器作为低能探测部分的主探测器,必然也会受到穿过HXMT带电粒子的干扰,为了去除带电粒子的干扰需要使用反符合探测器剔除这部分本底。本文研制了一种CCD反符合探测器,用以排除入射到低能主探测器上带电粒子产生的信号,从而提高CCD探测器的灵敏度。本文主要工作和结果如下：首先完成了反符合探测器的结构设计。采用塑料闪烁体为探测器介质,硅光电倍增管为光读出器件,将硅光电倍增管通过光导与塑料闪烁体耦合,并在塑料闪烁体表面覆盖反射层和避光层。确定了塑料闪烁体的选材和尺寸设计,同时确定了硅光电倍增管的选型。其次,研制了CCD反符合探测器的硬件电子学系统。包括电源模块,前放模块,以及线性放大器模块。由于CCD反符合探测器主要器件硅光电倍增管(MPPC)的增益对温度敏感,不同温度下增益随温度变化明显,严重影响了反符合探测器的性能,所以对MPPC的性能进行测试。为了实现其增益的稳定,研制了温度补偿电路解决了这一问题。最后对整个反符合探测器单元进行了测试研究。选择入射到地面的u子作为入射粒子,通过两重符合和三重符合,完成了反符合探测器的部分性能参数的测试。结果表明,所研制的探测器对穿透性荷电粒子的探测效率均高于90%,满足了设计要求。
[Abstract]:Hard X-Ray Modulation Telescope (HXMT) is a wide-band survey telescope. HXMT, which is developed on the basis of direct demodulation imaging method, will have a large number of charged particles passing through the main detector and depositing energy on it when it is in orbit. There are many background cases, which seriously reduce the detection sensitivity of the main detector. As the main detector of the low-energy detection part, the main detector must also be interfered by the charged particles passing through the HXMT. In order to remove the interference of charged particles, the anti-coincidence detector is used to eliminate this part of the background. In this paper, a CCD anti-coincidence detector is developed to exclude the signal generated by charged particles incident to the low-energy main detector. In order to improve the sensitivity of CCD detectors, the main work and results of this paper are as follows:. Firstly, the structure design of the anti-coincidence detector is completed. The plastic scintillator is used as the detector medium, the silicon photomultiplier tube is the light readout device, and the silicon photomultiplier tube is coupled with the plastic scintillator through the photoconductivity. The material selection and size design of plastic scintillator and the selection of silicon photomultiplier tube were determined. Secondly, the hardware electronic system of CCD anti-coincidence detector is developed, including power supply module, preamplifier module and linear amplifier module. Because the gain of CCD anti-coincidence detector is sensitive to temperature, the main device of CCD anti-coincidence detector is silicon photomultiplier tube. The gain varies obviously with the temperature at different temperatures, which seriously affects the performance of the anti-coincidence detector, so the performance of the MPPC is tested. In order to realize the stability of the gain, the temperature compensation circuit is developed to solve this problem. Finally, the whole anti-coincidence detector unit is tested and studied. The incident U element is selected as the incident particle, and some performance parameters of the anti-coincidence detector are tested by double coincidence and triple coincidence. The results show that, The detection efficiency of the detector for penetrating charged particles is higher than 90, which meets the design requirements.
【学位授予单位】：云南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TH743

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