Prof. Yi Wang (Tsinghua University)
The Compressed Baryonic Matter (CBM) experiment, constructed at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt, has decided to use the MRPC technology to build its Time-Of-Flight (TOF) wall. Tsinghua University is a group member of CBM-TOF and is doing research on low-resistivity glass and high rate MRPC. The volume resistivity of our glass is on the order of 1010 Ωcm. High rate MRPCs preserve an excellent 60ps intrinsic time resolution under a load of as much as 40 kHz/cm2 . According to the particle flux rate distribution, the whole CBM-TOF wall is divided into four rate regions named Region D, C, B and A (from inner to outer). The particle flux at the inner region D can be excess 20kHz/cm2. A pad-MRPC assembled with low resistive glass was designed to construct this area. This module consists of 10 0.22mm-gap and 16 readout pads (2cm x 2cm) . the prototype has been tested in the 2014 October GSI beam time and 2015 February CERN beam time. The calibration is done with CBM ROOT. A couple of corrections has been considered in the calibration and analysis process (including time-walk correction, gain correction, strip alignment correction and velocity correction) to access actual counter performances such as efficiency and time resolution. An efficiency of 98.8% and time resolution of 60ps are obtained. All these results show that the prototype is fully capable of the requirement of the CBM-TOF.
Bo Xie (Tsinghua University (CN)) Mr Christian Simon (Physikalisches Institut der Universität Heidelberg) Mr Jochen Frühauf (GSI) Mariana Petris (IFIN-HH Bucharest (RO)) Mihai Petrovici (National Institute for Physics and Nuclear Engineering (IFIN-HH)) Mladen Kis (GSI - Helmholtzzentrum fur Schwerionenforschung GmbH (DE)) Norbert Herrmann (Univ. Heidelberg) Pengfei Lyu (Tsinghua University) Dr Pierre-Alain Loizeau (GSI) Yongjie Sun (USTC)