The Study On Performance Of New Type Particle Detector-Multi-gap Resistive Plate Chamber

High energy heavy ion collision physics is a new research field, beginning from 1970s. Its aim is to study the characteristics of hadron matter under the extreme high temperature and high density conditions and search new phases by colliding two relativistic heavy nuclei. This novel field is of great significance to understand basic questions in particle physics, nuclear physics and cosmology. The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Lab (BNL) can accelerate gold nuclei to a few hundred GeV per nucleon. It is designed to search the possible new phase - Quark Gluon Plasma (QGP) and other new physics. The STAR detector is one of four experiments at RHIC. To improve the particle identification capability of STAR detector, a full barrel Time-Of-Flight (TOF) detector based on the Multi-gap Resistive Plate Chamber (MRPC) technology is being constructed by China and US institutions. MRPC is a new kind of gas detector with good time resolution and high detection efficiency. It is also capable to work with the incident rate up to hundreds of Hz/cm2 under the avalanche mode, which satisfies the request of high multiplicity detection.In this dissertation, I report the performances of MRPC from the following four aspects respectively: different working gas components, different electrode materials, different sizes of read-out strips and different module geometry structure. This main goal is to well understand the working principle and working condition of MRPC. All the experiments I report were made using the cosmic ray test system.The impact of working gas condition on the MRPC performance was studied, and the working condition changes include the change of working gas temperature and gas components. The experimental results show that with the increase of gas temperature, the dark current of MRPC rises, noise rate rises exponentially, the efficiency plateau moves towards lower HV and the average induced charge increases. Because the increase of temperature will lead to the decrease of primary ionization density, the mean free distance of electrons becomes longer, and ionization cross section of electrons increases. This will result in the increase of effective Townsend coefficient and the gas gain. Hence, the MRPC signal amplitude, noise rate, dark current and efficiency will go up. For the MRPC working with , and stable gas pressure, I propose to adjust the MRPC working condition using the formula within a small temperature scope. The impact of different...