The SoLid anti-neutrino detector's read-out system

The SoLid collaboration will probe the reactor anti-neutrino anomaly by performing a search for anti-neutrino oscillations within 10 m from the BR2 nuclear reactor, with the first modules being deployed early in 2017. Anti-neutrino events are identified in the SoLid detector by reconstructing the positron and neutron emitted from an inverse beta decay. Performing anti-neutrino measurements at ground level and close to a nuclear reactor is particularly challenging due to the high rate of background signals that can mimic an anti-neutrino interaction. The SoLid collaboration have developed a novel, highly segmented, composite scintillator detector to overcome these challenges. The detector allows for a robust neutron identification and event selections based upon both the topology as well as relative timing of the positron and neutron signals. The SoLid collaboration have developed an intelligent read-out system to reduce their 3200 silicon photomultiplier detector's data rate by a factor of 10000 whilst maintaining high efficiency for storing data from anti-neutrino interactions. The system employs an FPGA-level waveform characterisation to trigger on neutron signals. Following a trigger, data from a space-time region of interest around the neutron will be read out using the IPbus protocol. This region of interest will be sufficiently large to contain any positron candidate signals. In these proceedings the SoLid detector concept will be introduced, the design of the read-out system will be explained and results showing the performance of prototype version of the system will be presented.