The Physics and Nuclear Nonproliferation Goals of WATCHMAN: A WAter CHerenkov Monitor for ANtineutrinos

Abstract

This article describes the physics and nonproliferation goals of WATCHMAN, the WAter Cherenkov Monitor for ANtineutrinos. The baseline WATCHMAN design is a kiloton scale gadolinium-doped (Gd) light water Cherenkov detector, placed 13 kilometers from a civil nuclear reactor in the United States. In its first deployment phase, WATCHMAN will be used to remotely detect a change in the operational status of the reactor, providing a first- ever demonstration of the potential of large Gd-doped water detectors for remote reactor monitoring for future international nuclear nonproliferation applications. During its first phase, the detector will provide a critical large-scale test of the ability to tag neutrons and thus distinguish low energy electron neutrinos and antineutrinos. This would make WATCHMAN the only detector capable of providing both direction and flavor identification of supernova neutrinos. It would also be the third largest supernova detector, and the largest underground in the western hemisphere. In a follow-on phase incorporating the IsoDAR neutrino beam, the detector would have world-class sensitivity to sterile neutrino signatures and to non-standard electroweak interactions (NSI). WATCHMAN will also be a major, U.S. based integration platform for a host of technologies relevant for the Long-Baseline Neutrino Facility (LBNF) and other future large detectors. This white paper describes the WATCHMAN conceptual design,and presents the results of detailed simulations of sensitivity for the project's nonproliferation and physics goals. It also describes the advanced technologies to be used in WATCHMAN, including high quantum efficiency photomultipliers, Water-Based Liquid Scintillator (WbLS), picosecond light sensors such as the Large Area Picosecond Photo Detector (LAPPD), and advanced pattern recognition and particle identification methods.

35 pages, 9 figures

References in corpus (3)

• Detection possibility of the pair-annihilation neutrinos from the neutrino-cooled pre-supernova star
• Observation of Neutrons with a Gadolinium Doped Water Cerenkov Detector
• Advanced Scintillator Detector Concept (ASDC): A Concept Paper on the Physics Potential of Water-Based Liquid Scintillator

Cited by in corpus (13)

• Performance of Large Area Picosecond Photo-Detectors (LAPPD)
• MeV-scale performance of water-based and pure liquid scintillator detectors
• Cherenkov and Scintillation Separation in Water-Based Liquid Scintillator using an LAPPD
• EOS: a demonstrator of hybrid optical detector technology
• Water-based Liquid Scintillator Detector as a New Technology Testbed for Neutrino Studies in Turkey
• Applied Antineutrino Physics 2018 Proceedings
• Air-Transfer Production Method for Large-Area Picosecond Photodetectors
• Characterization of the scintillation response of water-based liquid scintillator to alpha particles, and implications for particle identification
• Detector R&D for ANNIE and Future Neutrino Experiments
• Antineutrino Detectors Remain Impractical for Nuclear Explosion Monitoring
• Liquid-organic time projection chamber for detecting low energy antineutrinos
• Far-Field Monitoring of Reactor Antineutrinos for Nonproliferation
• Reactor Antineutrino Signals at Morton and Boulby