The Construction, Test And Simulation Of Micromegas Detector

As a new generation micro-pattern gaseous detector, Micromegas detector was introduced by Scalay Lab in 1996. Because of the high-rate capability, the excellent spatial and time resolutions, Micromegas detector has been widely developed for many different applications in the last few years. We have primarily designed and studied the Micromegas detector in the institute of Modern Physics of CAS since 2006, in which some better results were gained and laid a solid foundation for its further application.The main contents of the thesis are as following:In experiment aspects, the characteristics of Micromegas detector, such as counting rate plateau curve, gain and energy resolution, were primarily tested and studied.In simulation aspects, firstly, the physical processes of electron drift and multiplication in Micromegas detector were studied using a 3D simulation. The gain and spatial resolution under different conditions were investigated and compared with experimental data. The results of the simulation were consistent with that of the experiment. Secondly, the spatial resolution of Micromegas as a neutron detector and the influence of high gamma background on the spatial resolution were done by Geant4 toolkit. A new track reconstruction method based on time coincidence technology-the delay method, was developed to obtain the incident neutron position. The results show that the spatial resolution can be as good as 100μm and the spatial resolution is insensitive to gamma background, if the delay method proposed by our group is used.At last, some conclusions and further research directions are discussed briefly.