论文标题
使用测试梁数据和其反应的现象学建模研究picosec-Micromegas检测器
Study of the PICOSEC-Micromegas Detector with Test Beam Data and Phenomenological Modelling of its Response
论文作者
论文摘要
在这项工作中，提出了Picosec探测器的研发工作的一部分。 Picosec探测器是基于Micromegas检测器的新型气体探测器，该检测器是由RD-51 Picosec协作开发的。 Picosec检测器不依赖传统的直接电离，而是通过使用光电电极将Cherenkov光子转换为电子来利用Cherenkov辐射的迅速定时特征。该检测器已被放入两种类型的测试中，其中收集了实验数据。一种涉及激光束和在CEA-SACLAY处的单个光电子响应，而另一个涉及在Cern SPS H4次级光束线上的150 GEV MUON的测试光束，具有多个光电子。总结了对检测器时间的统计分析中采用的方法，并在其应用中为单个光电子带来了76 ps的最佳时间分辨率。观察到平均时间对电子峰大小的奇怪依赖性，这模仿了“时间步行”效果的行为。开发了检测器的模拟来研究时间的特性，这也是论文的主要范围。经过详细的研究，发现气态混合物中的电子在第一次乘法之前和之后以不同的漂移速度移动，引入了这种“时间步行”效果，并提供了对此效果的现象学解释。最后，开发了每个粒子提取的光电子的平均光电数估计的最大似然统计方法，并以每个粒子等于10.4的平均光电子数量达到24 ps的最佳时间分辨率。在这项工作中，对新的检测器获得了深刻的了解，该探测器在充满气体探测器的领域带来了前所未有的结果。
In this work, a part of the Research and Development effort of the PICOSEC detector is presented. The PICOSEC detector is a novel gas-filled detector, based on the Micromegas detector, which has been developed by the RD-51 PICOSEC collaboration. Instead of relying on traditional direct ionization, the PICOSEC detector takes advantage of the prompt timing characteristics of Cherenkov radiation by converting the Cherenkov photons into electrons through the use of a photocathode. The detector has been put into two type of tests where experimental data are collected. One involves a laser beam and a single photoelectron response at CEA-SACLAY, while the other involves a test beam of 150 GeV muons at the CERN SPS H4 secondary beamline, with multiple photoelectrons. The methods employed in the statistical analysis of the detector's timing properties are summarized and in their application an optimal time resolution of 76 ps is achieved for single photoelectrons. A strange dependence of the mean timing on the size of the electron peak is observed, which mimics the behaviour of the "time walk" effect. A simulation of the detector is developed to study the timing properties, which is also the main scope of the thesis. After a detailed investigation, it is found that the electrons in the gaseous mixture move with a different drift velocity before and after the first multiplication, introducing this "time walk" effect, and a phenomenological explanation of this effect is provided. Finally, a maximum likelihood statistical method for the estimation of the mean number of photoelectron extracted per particle is developed and an optimal time resolution of 24 ps is achieved with a mean number of photoelectrons per particle equal to 10.4. In this work, a deep understanding is acquired on a new detector which has brought upon unprecedented results in the field of gas-filled detectors.
