Highlight on Supernova Early Warning at Daya Bay

• Published in: Physics procedia Vol. 61; pp. 802 - 806
• Main Author: Wei, Hanyu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2015
• Subjects: Daya Bay reactor neutrino experiment; supernova early warning; supernova early warning; Daya Bay reactor neutrino experiment
• ISSN: 1875-3892; 1875-3892
• DOI: 10.1016/j.phpro.2014.12.103

Providing an early warning of supernova burst neutrinos is of importance in studying both supernova dynamics and neutrino physics. The Daya Bay Reactor Neutrino Experiment, with a unique feature of multiple liquid scintillator detectors, is sensitive to the full energy spectrum of supernova burst electron-antineutrinos. By utilizing 8 Antineutrino Detectors (ADs) in the three different experimental halls which are about 1 km's apart from each other, we obtain a powerful and prompt rejection of muon spallation background than single-detector experiments with the same target volume. A dedicated trigger system embedded in the data acquisition system has been installed to allow the detection of a coincidence of neutrino signals of all ADs via an inverse beta-decay (IBD) within a 10-second window, thus providing a robust early warning of a supernova occurrence within the Milky Way. An 8-AD associated supernova trigger table has been established theoretically to tabulate the 8-AD event counts’ coincidence vs. the trigger rate. As a result, a golden trigger threshold, i.e. with a false alarm rate < 1/3-months, can be set as low as 6 candidates among the 8 detectors, leading to a 100% detection probability for all 1987A type supernova bursts at the distance to the Milky Way center and a 96% detection probability to those at the edge of the Milky Way.