Speaker
Mr
Jingbo WANG
(Tsinghua university)
Description
The proposed Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, will use a TOF system based on MRPC technology for hadron identification. The challange is to keep efficiencies above 90 % and time resolutions well below 80 ps at particle fluxes up to 20 kHz/cm2, which is not accessible to conventional float-glass MRPCs. For this purpose, a kind of low-resistivity doped glass with bulk resistivity on the order of 1010 Ωcm was produced at Tsinghua University. Two real-size high rate prototypes based on this material were developed and tested in-beam.
In the current conceptual design, the whole CBM-TOF wall is arranged in four “rate regions”. In the inner rate regions (region 1-3), the particle flux ranges from 3.5 kHz/cm2 to 25 kHz/cm2, thus high-rate MRPCs with low-resistive glass electrodes are presently the best choice. In the outmost rate region (region 4), the average particle flux is about 1 kHz/cm2, so MRPCs made out of float glass might be used. Here we propose a slightly different conceptual design for building the TOF wall by resorting to a single technology based on low-resistive doped glass and relying on small structural modifications of the two modules developed and tested during the last 2 years. It’s very inspiring that the appropriate MRPC prototypes have been already tested with high intensity beam and the performance can fulfill the CBM requirements.
We will also present the results from the latest beam test of the two real-size modules at the continous electron beam of the Electron Linac with high Brilliance and low Emittance (ELBE) facility at Helmholtz-Zentrum Dresden-Rossendorf (HZDR), in April 2011. The counters show large efficiency plateaus by as much as 600volts, and intrinsic resolutions down to 50ps. Under conditions of localized irradiation, the rate capability of the strip counter reaches up to 200 kHz/cm2, while it is higher for the pad counter (~300 kHz/cm2).
Primary author
Mr
Jingbo WANG
(Tsinghua university)
