| The Beijing Electron Positron Collider (BEPC) and the Beijing Spectrometer (BES) have been upgraded since July, 2008. The systems are named BEPC II and BESⅢrespectively.As the major part of the BEPCⅡ, the BESⅢincludes a drift chamber, a time-of-flight system and a muon identifier system and so on. Its function is to measure and identify a substantial fraction of the particles (PID) produced by the BEPC II. Since the accomplishment of upgrading, BESⅢhas obtained a serial of great achievement.One part of BESⅢ, time-of-flight system (TOF) measures the relative arrival time of particle generated by the electron-position collisions in the BEPC II. The TOF system is divided into two parts: the end-cap TOF (ETOF) and the barrel TOF (BTOF). The time resolution of BTOF is less than 90ps, which means it is the best TOF detector using PMT as the detector in the world. However, the time resolution of the ETOF is more than 138ps, which because of the influence of noise in the system and some other reason which increases the uncertainty of the particle's information generated by the detector.In order to increase the capability of PID and the time resolution of ETOF, the ETOF improvement has been proposed and the whole projected is under design. In the upgrading system, MRPC is used as the detector. This detector has some advantages, such as the high time resolution and efficiency. It has been used in ALICE TOF in LHC and STAR TOF in BNL successfully. To meet the demand of improvement of ETOF, the readout electronics system is also improved and achieves time measurement with high resolution (RMS < 25ps).This thesis discusses the implement of the readout electronics system and mainly discusses the method to achieve time measurement, as well as the technology used in the system.In the physics experiment, the time-of-flight measurement consists of time discrimination and time-to-digital converter (TDC). The method of time measurement will be discussed in the chapter 2. We discuss the leading-end discrimination and counter type TDC. The characteristic of a typical TDC-HPTDC is mentioned in the chapter, too. In the step of discriminating, we need to correct the error caused by"time walk"effect, such as the method of charge correcting and amplitude correcting. Currently, the method of charge correcting has been implemented and the charge measurement is required. The typical charge measurement is wave sampling, charge-to-time conversion and charge–to-voltage conversion. The time-over-threshold (TOT) technique is based on charge–to-time converter is introduced in the chapter, too.In chapter 3, some particle collider's readout electronics systems are introduced. Considering the feature of the MRPC used in the upgrading ETOF, we proposed a practical scheme: using TOT to accomplish signal amplification and time discrimination and counter type TDC to digitalize time. The"time walk"effect correction is implemented by charge correcting. Both time measurement and charge measurement can be achieved by HPTDC.In chapter 4, we discuss the design of the whole electronics system. The system includes the front-end electronics module (FEE), the time-to-digital module (TDIG), the auxiliary module (CTTP), and the clock module. We mainly discuss the scheme of the TDIG module and some detail.In chapter 5, we introduce the test result of readout electronics, using signal generator. We test the time resolution and INL of each channel of TDIG module, as well as the whole readout electronics. The result shows the readout electronics system meets the demand of ETOF upgrading.
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