Cosmic Ray Test Platform And High Resolution MRPC Technology

High-resolution cosmic ray test platform is an important basis for particle detector research and development in laboratory. Multi-gap Resistive Plate Chamber (MRPC) developed recently is a gaseous detector with many advantages such as high time resolution, simple structure, low cost and so on. Cosmic ray test platform based on MRPC technology still have many problems to be solved. To this end, various studies about the high-resolution MRPC technology are carried out in this thesis, including:the design and production of MRPC module, fast electronics amplification technology, high-performance data acquisition system and the analysis methods for experimental data.During the research for this thesis, the author has an in-depth study on high time resolution MRPC technology and the related experimental methods, participated in the development of a few different structures of MRPC and developed a number of cosmic ray test platforms for various experiment needs, including:1) the volume production and testing for STAR-MTD MRPC detector and the related cosmic ray test platform development;2) the development of a high-resolution large-area cosmic ray test platform based on the MRPC technology and the study of the related experimental methods for one-dimensional muon imaging experiment;3) the development of MRPC module for BESⅢ-ETOF upgrade and the related cosmic ray test platform. These research projects are carried out for the first time and lead to a lot of new results.Since muons do not participate in strong interactions, they are the ideal probes for the strong-interaction QGP. STAR increase the outermost muon detectors to measure the muons with a few GeV/c momentum at mid-rapidity for measurements of di-muon pairs from QGP thermal radiation, quarkonia, light vector mesons, possible correlations of quarks and gluons as resonances in QGP and Drell-Yan production, as well as heavy flavor hadrons through their semi-leptonic decays into single muons. This requires for the Muon Telescope Detector (MTD) to have sufficient time and special resolution for muons with momentum of several GeV/c, and large detecting area as moun detectors located at the outermost. So the MRPC technology is selected for the MTD. The data analysis results showed that, the time resolution of the MTD<100ps, the detection efficiency>95%and the position resolution～1cm. High energy physics laboratory of USTC is in charge of the production and test of50detector modules, the author participated in the production of several detector modules, and built a cosmic ray test platform using two scintillator and four photomultiplier tubes. The front-end electronics (FEE) used for the test of MRPC are based on MAX3760amplifier. The author also make some studies about basic structure of the detector, the production process, the working principle, the output signal characteristics, and the FEE based on MAX3760amplifier and NINO amplifier, and also the corresponding experimental data analysis methods in the production and testing process.The front-end electronics system based on MAX3760amplifier needs both ADC and TDC to collect the time and amplitude information of the MRPC detector, and this makes the FEE system much more complicated, which leads to the difficulty of the simultaneous testing for several MRPC modules. To simplify the experimental system and measure the hitting position and time of each muon simultaneously, the author build a high-resolution large-area cosmic ray test platform with a data acquisition system based on HPTDC using STAR-MTD MRPC modules with NINO based FEE。The performance of the test platform can achieve:the reference time～40ps, the two-dimensional spatial resolution～6mm, the detection efficiency>95%. In addition, the author carry out the experimental study for the first time on the principle of cosmic ray muon imaging, using this cosmic ray test system consisting of four MRPCs.The current BESIII-ETOF detector is based on EJ204scintillator and R5924photomultiplier tubes. The time resolution for muon, electronic and pion is110ps,148ps and138ps respectively, and π/K separation (within2σ confidence level) can be1GeV/c. The electron multiple scattering between MDC and ETOF results in the secondary particles multiple hit on the431mm long scintillator, thus deteriorates the time resolution. MRPC has good time resolution performance (total resolution less than80ps), and small readout pad (about25mm), can effectively solve the problem of multiple hit, the expected π/K separation can reach1.4GeV/c (within2σ confidence level) after the upgrade of MRPC ETOF system. We have compared the performance of two MRPC modules designed for BESⅢ-ETOF upgrade using the beam of Beijing Electron Positron Collider, and eventually decided which module to use after beam testing. We are also in charge of the volume production and testing of BESIII-ETOF MRPC modules. To test the time and spatial resolution simultaneously, the author built a cosmic ray test system based on MRPC telescope and triggered by scintillation detectors, and decrease the influence of internal clock non-synchronization among HPTDCs, by providing a reference signal to each HPTDC, and finally accomplish the simultaneous test of four detectors.During the study period, the author has been to the University of Michigan (April2011to December2012) participated in the study of the frequency scanned interferometry. This study is an R&D project for the International Linear Collider (ILC) of track detectors alignment. The research results in this work include the following aspects:1) apply the two-channel dual laser measurement method for eliminating the interference of environmental factors, and the distance measurement accuracy achieves-0.5μm;2) build the CCD camera system and ACU-RITE system for reference;3) improve the beam unit for6-channel measurements, and the results have been compared with the CCD camera system and the ACU-RITE system. The accuracy of each channel can be better than1μm;4) achieve3-channel2-dimensional measurement by the angle calculating, the accuracy in two dimensions are both better than1μm;5) further improve the beam unit, achieve2,3-dimensional measurement with the improved coordinate reconstruction method. Position precision in x, y direction is better than1μm, while in z direction is2-3μm (affected by the track accuracy in z direction) The results are better than the recommended accuracy for the SiD tracking detector alignment.