Crosstalk research of long strip timing RPC

The time-of-flight (TOF) wall of CBM is proposed to be assembled with MRPCs. In a relative high particle multiplicity situation (about 20kHz/cm²), multi-hit capability is one of the most demanding requirement of the detector. Crosstalk is an important reason for the deterioration the multi-hit capability of a detector. To reduce the crosstalk level, a kind of shielded long-strip two-end readout MRPC was developed. 1mm width guard strips were added between strips of a 1m-long MRPC. Beam test with 2.5GeV protons was performed in GSI in August, 2009. Horizontal and vertical scans were done. Combined with data from silicon detector, we get the crosstalk between four neighbor strips. The results show that the crosstalk level can be reduced and double hits can affect the time resolution. It also shows that the crosstalk increase with high voltage and decrease with surface resistivity of electrode.