Muon tomography is a promising method in the detection and imaging of high Z material. In general, considering the quality of track reconstruction in imaging, a detector of good position resolution, high efficiency and large area is required. This paper presents the design and study of a prototype of position sensitive MRPC with 0.15 mm narrow gas gap and 2.54 mm strip readout. Through a cosmic-ray experiment, the performance of MRPC module is carefully observed and each channel is calibrated. Through an X ray experiment with a narrow slit, the position resolution is studied. The results show that the time resolution of the module can reach 61ps and the spatial resolution can reach 0.36 mm.
An MRPC prototype for the future CBM-TOF inner area has been developed.The counter assembled with low resistive glass consists of 10×0.22 mm gas gaps and 2×8 readout pads.The size of each pad is 20 mm×20 mm with an interval of 2 mm between pads.The signals of the counter are collected by 4 eight-pin connectors.Preliminary tests performed with cosmic-rays showed an efficiency over 98%and a time resolution around 60 ps.The measured crosstalk,dark current and dark rate were at a very low levels.Results under uniform irradiation performed at JINR with high energy deuteron showed a time resolution of40–50 ps and over 98%efficiency at a low flux rate,meanwhile at a flux up to 70 kHz/cm2,93%efficiency and 77 ps time resolution still remained.These excellent performances call fully meet the demand of CBM-TOF inner wall.
ZHU WeiPingWANG YiFENG ShengQinWANG JingBoHUANG XinJieSHI LiBABKIN V.GOLOVATYUK V.RUMIANTCEV M.
With the constant increase of accelerator luminosity, the rate requirements of MRPC detectors have become very important, and the aging characteristics of the detector have to be studied meticulously. An online aging test system has been set up in our lab, and in this paper the setupof the system is described and the performance stability of a high-rate MRPC studied over a long running time under a high luminosity environment. The high rate MRPC was irradiated by X-rays for 36 days and the accumulated charge density reached 0.1 C/cm2. No obvious performance degradation was observed for the detector.
The Compact Muon Solenoid （CMS） at LHC intends to use a high rate trapezoid MRPC for the muon system upgrade, but the size of the MRPC is limited by the dimensions of low resistivity glass. We have designed a prototype of a large MRPC in which the electrodes are developed by gluing two pieces of glass plates. Simulation of the weighting field and cosmic ray test shows that the efficiency of the glued MRPC is higher than 96% and the time resolution is better than 71 ps.
