The trigger system of a large area RPC TOF-tracker muon telescope

摘要

The TOF-tracker concept, the simultaneous measurement of accurate time and bidimensional space coordinates in a single gaseous detector, has been previously demonstrated based on Resistive Plate Chamber (RPC) technology. Recently, a larger area, 1550 × 1250mm~2, RPC detector has been built. Signals are induced on metallic strips located in each side of the RPC active volume and coupled to both charge-sensitive and timing circuits, that can be used to generate a coincidence trigger. In this work, the architecture and performance of the trigger system of the detector is reported. The system is based on off-the-shelf inexpensive modules and in a custom program written in VHDL running in a Xilinx Spartan-6 FPGA. It is fast, fully parameterized and supports several trigger strategies, allowing at the same time the collection of data referring to the operating condition of the detector, relevant for tests and detector maintenance.