A. Cabrera

The Trigger and Timing System of the Double Chooz Experiment

Modern precision neutrino experiments like Double Chooz require a highly efficient trigger system in order to reduce systematic uncertainties. The trigger and timing system of the Double Chooz experiment was designed according to this goal. The Double Chooz trigger system is driven by the basic idea of triggering on multiple thresholds according to the total visible energy and additionally triggering on the number of active photomultiplier tubes (PMTs) in the detector. To do so, the trigger system continuously monitors the analogue signals from all PMTs in the detector. The amplitudes of these PMT-signals are summed for groups of certain PMTs (group signals) and for all PMTs (sum signal), respectively. The group signals are discriminated by two thresholds for each input channel and four thresholds for the sum signal. The resulting signals are processed by the trigger logic unit which is implemented in a FPGA. In addition to the proper trigger, the trigger system provides a common clock signal for all subsequent data acquisition systems to guarantee a synchronous readout of the Double Chooz detectors. The present design of the system provides a high flexibility for the applied logic and settings, making it useful for experiments other than Double Chooz. The Double Chooz trigger and timing system was installed and commissioned in 2011. This article describes the hardware of the trigger and timing system. Furthermore the setup, implemented trigger logic and performance of the trigger and timing system for the Double Chooz experiment is presented.

Online monitoring system for Double Chooz experiment

Double Chooz is a reactor-neutrino experiment at Chooz nuclear power plant in France to measure the unknown neutrino mixing angle θ13 with a better sensitivity than the current best limit. A remote-monitoring framework has been developed to check status of DAQ systems, which enables collaborators off-site to access online monitoring data through the internet. As for these graphical user interfaces (GUI) are developed with platform independent technologies to be available through the internet. As fault tolerant monitoring systems in Double Chooz, Gaibu (external in Japanese) system and Log-Message system have been developed. Gaibu system works as an alarm message provider working outside DAQs and Log-Message system is a log file manager. Developments of these systems are almost finished and we are preparing software commissioning at the far detector site now.

Neutrino-antineutrino identification in a liquid scintillator detector: Towards a novel decay-at-rest-based neutrino CPV framework

Abstract We introduce a novel approach to investigate CP violation in the neutrino sector, based on the simultaneous detection of ν e and ν e stemming from the oscillation of ν μ and ν μ produced in the decay at rest of π s and μ s at a beam target. This approach relies on a novel liquid scintillator detector technology expected to yield unprecedented identification of ν e and ν e charged-current interactions, which we investigate by means of Monte Carlo simulations. Here we report preliminary results concerning both the detection technique and its physics reach.