Time and position resolution of high granularity, high counting rate MRPC for the inner zone of the CBM-TOF wall

Abstract

Multi-gap RPC prototypes with readout on a multi-strip electrode were developed for the small polar angle region of the CBM-TOF subdetector, the most demanding zone in terms of granularity and counting rate. The prototypes are based on low resistivity (∼10 10 Ωcm) glass electrodes for performing in high counting rate environment. The strip width/pitch size was chosen such to fulfill the impedance matching with the front-end electronics and the granularity requirements of the innermost zone of the CBM-TOF wall. The in-beam tests using secondary particles produced in heavy ion collisions on a Pb target at SIS18 -GSI Darmstadt and SPS -CERN were focused on the performance of the prototype in conditions similar to the ones expected at SIS100/FAIR. An efficiency larger than 98% and a system time resolution in the order of 70 -80 ps were obtained in high counting rate and high multiplicity environment. * mpetris@nipne.ro 1

Performance studies of MRPC prototypes for CBM

“…These two effects counterbalance and give a minimum at some intermediate cluster size. This trend was also observed in [14]. Another interesting dependence is the time distribution between HD-P2 and reference counter and the system time resolution as function of the cluster multiplicity (see fig 6).…”

“…The HD-P2 prototype was replaced after some testing time by the THU-strip. This setup (see figure 2) was part of a bigger setup including other MRPC counters which were tested in parallel [10]. Also part of the setup was a diamond detector placed in the beam a few cm in front of the target.…”

“…The requirements of the full system is a time resolution better than 80 ps at an efficiency higher than 95 %. Since the charged particle flux drops exponentially from small angle (2.5 • ) to large angle (25 • ), ranging from 25 kHz/cm 2 to 1 kHz/cm 2 high rate capable MRPCs with low-resistive electrode material [4][5][6][7][8][9][10] but also with thin float glass [11,12] and with different granularities were developed. An overview of the conceptual design of the CBM ToF-wall is given in [13].…”

A method to adjust the impedance of the transmission line in a Multi-Strip Multi-Gap Resistive Plate Counter

“…The detector inner geometry, schematically presented in Fig. 1, is the same as for the previous prototypes already reported [4,8]. It has a structure of two stacks symmetrically disposed relative to the central readout electrode.…”

High time resolution, two-dimensional position sensitive MSMGRPC for high energy physics experiments

“…Therefore, we have focused on an intense R&D activity [9,10,11] for development of a Multi-Gap Resistive Plate Chamber with differential Multi-Strip readout (MSMGRPC) for the most demanding region of the TOF wall, the region of low polar angles (2.5 0 -11 0 ) called inner zone. We report in this paper latest results of the activity devoted to develop a MSMGRPC prototype with the highest granularity of the CBM-TOF wall.…”