A new front-end electronics chain for timing RPCs

Recent advances in electronics and counter construction techniques have pushed the timing resolution of Resistive Plate Chambers below 50 ps σ, with a detection efficiency of 99% for MIPs. In this paper we describe a new front end electronic chain for accurate time and charge measurement in these devices. The circuit includes a fast (2.5 GHz) two-stage amplifier based on MMICs that feeds a fixed threshold discriminator followed by an external TDC. The amplified signal is also buffered into an external ADC for charge digitisation. All components are commercially available and their number is rather reduced. The system was tested with realistic detector-generated test signals, yielding a timing resolution around 10 ps σ for signal charges above 100 fC and a charge resolution of 3.2 fC