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Multi-gap resistive plate chamber (MRPC), which is mostly developed in high energy physics domain with excellent time resolution, is also highlighted in imaging applications. A set of 50 cm×50 cm large area MRPC with high position resolution was successfully developed by our group and different experiments have been done to test its performances. Cosmic ray muons were used to do the test and proper high voltage and working gas were chosen. Data analysis indicates its good detection efficiency and good position resolution, which encourages further study of its application in RPC-PET and muon tomography.

A kind of two-dimensional readout electrode structure for the induced signal readout of MRPC has been studied in both simulation and experiments. Several MRPC prototypes are produced and a series of test experiments have been done to compare with the result of simulation, in order to verify the simulation model. The experiment results are in good agreement with those of simulation. This method will be used to design the two-dimensional signal readout mode of MRPC in the future work.

A prototype RPC detector with a 2-mm readout strip pitch has been built for research into its position resolution. After determining the optimal threshold and working voltage, the efficiency and position resolution of this prototype RPC detector have been studied carefully. Using cosmic-ray muons with different directions and incident positions, we have obtained less than 0.5-mm average statistical errors of position resolution for two different RPC readout structures: 1- and 1.7-mm readout strip widths. The results show that the RPC can also give high position resolution with very little variation from its traditional structure. This will lead to possible applications of the RPC in medical imaging and other domains.

A digital radiography system was constructed in a portable version suitable for field use. The system uses pulsed X-ray generator. Radiographic images are formed using scintillating screen coupled to a charge-coupled device (CCD) camera and transmitted to a portable computer through the network. The system works well on safety inspection, non-destructive testing and medical diagnosis. The structure and performance of the system are presented.

A kind of multi-gap resistive plate chamber (MRPC) was developed for the STAR experiment at RHIC. The MRPC has excellent time resolution with high efficiency and can be used as the time-of-flight detector. In this paper, we present some performance of MRPC tested by cosmic ray, and performances of MRPC working in different gas mixture and in different temperature are also illustrated.

The methods for the manufacture and test of multi-gap resistive plate chambers are described. Multi-gap resistive plate chamber (MRPC) will be used as time-of-flight detector for the STAR experiment at RHIC. The technique of manufacture described not only ensures the quality of MRPCs but also improves the efficiency of manufacture. The method for fast test of MRPC modules can also improve the efficiency of the test greatly.

A four-channel digital flash X-ray imaging system has been developed in our lab. The four flash X-ray heads and four detectors can be used to obtain four radiographic images at four time intervals of an explosion and ballistic trajectory. The cascaded imaging system mainly consists of three parts: (1) a phosphor screen to convert incident X-rays into visible photons; (2) a lens to efficiently collect visible photons emitted by the phosphor screen; and (3) a charge coupled device image sensor to obtain the visible light image. From the analysis of signal and noise propagation, the system is not X-ray quantum-limited, rather the system has secondary quantum sink at the light collecting stage. The construction of the system, theoretical and experimental analysis of performance are presented.