A timing RPC with low resistive ceramic electrodes

Abstract

A : For precise start time determination a Beam Fragmentation T 0 Counter (BFTC) is under development for the Time-of-Flight Wall of the Compressed Baryonic Matter Spectrometer (CBM) at the Facility for Antiproton and Ion Research (FAIR) at Darmstadt/Germany. This detector will be located around the beam pipe, covering the front area of the Projectile Spectator Detector. The fluxes at this region are expected to exceed 10 5 cm −2 s −1 . Resistive plate chambers (RPC) with ceramic composite electrodes could be use because of their high rate capabilities and radiation hardness of material. Efficiency ≥ 97 %, time resolution ≤ 90 ps and rate capability ≥ 10 5 cm −2 s −1 were confirmed during many tests with high beam fluxes of relativistic electrons. We confirm the stability of these characteristics with low resistive Si 3 N 4 /SiC floating electrodes for a prototype of eight small RPCs, where each of them contains six gas gaps. The active RPC size amounts 20×20 mm 2 produced on basis of Al 3 O 2 and Si 3 N 4 /SiC ceramics. Recent test results obtained with relativistic electrons at the linear accelerator ELBE of the Helmholtz-Zentrum Dresden-Rossendorf with new PADI-10 Front-end electronic will be presented.

The CBM Time-of-Flight system

“…The gap size is 250 µm. More information about the counter design and test beam results can be found in [4][5][6][7]. Above an aperture of 2.5 • glass MRPCs are foreseen.…”