Evaluation of Gadolinium's Action on Water Cherenkov Detector Systems with EGADS

Artículo escrito por un elevado número de autores, sólo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiera, y los autores pertenecientes a la UAM
Used for both proton decay searches and neutrino physics, large water Cherenkov (WC) detectors have been very successful tools in particle physics. They are notable for their large masses and charged particle detection capabilities. While current WC detectors reconstruct charged particle tracks over a wide energy range, they cannot efficiently detect neutrons. Gadolinium (Gd) has the largest thermal neutron capture cross section of all stable nuclei and produces an 8 MeV gamma cascade that can be detected with high efficiency. Because of the many new physics opportunities that neutron tagging with a Gd salt dissolved in water would open up, a large-scale R&D program called EGADS was established to demonstrate this technique’s feasibility. EGADS features all the components of a WC detector, chiefly a 200-ton stainless steel water tank furnished with 240 photo-detectors, DAQ, and a water system that removes all impurities from water while keeping Gd in solution. In this paper we discuss the milestones towards demonstrating the feasibility of this novel technique, and the features of EGADS in detail
This work was supported by the JSPS KAKENHI Grant Numbers JP21224004, JP26000003, JP24103004 and JP17H06365. Funding support was provided by Kavli IPMU (WPI), the University of Tokyo and the US Department of Energy. We thank the “Consorcio Laboratorio Subterraneo de Canfranc” (Spain) and the Boulby Underground Research Laboratory and in particular the staff of the BUGS facility (UK) for supporting the low-background materials screening work. Some of us have been supported by funds from the European Union H2020-MSCA-RISE-GA872549-SK2HK, the Spanish Ministry of Science and Innovation (grant PGC2018-099388-B-100), the Science and Technology Facilities Council (STFC) and GridPP, UK, and the European Union’s H2020 -MSCA-RISE-2018 JENNIFER2 grant agreement no. 822070