Neutrino physics with an opaque detector

Null Author_Id ,M Bongrand,J.-S Stutzmann,A Le Nevé,J Busto,C Santos,S Schoppmann,G Fiorentini,N Roy,D Navas-Nicolás,M Grassi,A Givaudan,C Buck,S Jiménez,A Cabrera,T J C Bezerra,J C C Porter,G Ortona,J Dos Anjos,M Sisti,A Pin,P Govoni,J Martino,J P Ochoa-Ricoux,M Chen,E Chauveau,G De Conto,B Roskovec,Virginia Strati ,P Loaiza,B Gramlich,M Obolensky,Andrea Serafini ,C Bourgeois,D Bretón ,P Chimenti,A Verdugo,H De Kerret,Fabio Mantovani ,C Palomares,Christiane Frigerio Martins ,C Hugon,J Hartnell,L Manzanillas,Yang Han ,L Stančo ,S Dusini,Hiroshi Nunokawa ,Enrique Calvo Alamillo ,M.s Pravikoff ,L Simard,F Suekane,C Vrignon,Ch Marquet ,F Pessina,F Dal Corso,Angel Abusleme ,B Viaud,S J Wagner ,Jihane Maalmi ,Mathieu Roche ,Cristina Volpe ,F Yermia

doi:10.1038/s42005-021-00763-5

Abstract

In 1956 Reines & Cowan discovered the neutrino using a liquid scintillator detector. The neutrinos interacted with the scintillator, producing light that propagated across transparent volumes to surrounding photo-sensors. This approach has remained one of the most widespread and successful neutrino detection technologies used since. This article introduces a concept that breaks with the conventional paradigm of transparency by confining and collecting light near its creation point with an opaque scintillator and a dense array of optical fibres. This technique, called LiquidO, can provide high-resolution imaging to enable efficient identification of individual particles event-by-event. A natural affinity for adding dopants at high concentrations is provided by the use of an opaque medium. With these and other capabilities, the potential of our detector concept to unlock opportunities in neutrino physics is presented here, alongside the results of the first experimental validation.

Highlights

In 1956 Reines & Cowan discovered the neutrino using a liquid scintillator detector
Given the extremely small probability for neutrinos to interact with matter, achieving larger detectors has been a standing challenge throughout the history of ν physics
The results indicate that 2 MeV e−’s can be feasibly distinguished from γ’s with a contamination factor better than 10−2, which is unprecedented for liquid scintillator detector (LSD) at these energies

Summary

Introduction

In 1956 Reines & Cowan discovered the neutrino using a liquid scintillator detector. The neutrinos interacted with the scintillator, producing light that propagated across transparent volumes to surrounding photo-sensors. This article introduces a concept that breaks with the conventional paradigm of transparency by confining and collecting light near its creation point with an opaque scintillator and a dense array of optical fibres This technique, called LiquidO, can provide high-resolution imaging to enable efficient identification of individual particles event-by-event. The liquid scintillator detector (LSD) developed by Cowan, Reines et al for ν detection exploited a well-established radiation detection technique at the time, whereby molecular electrons are excited by the passage of charged particles produced by ν interactions and emit light upon de-excitation[2]. The main volume is subdivided into optically-decoupled compartments, so instead of a single monolithic volume a granular one is used This allows recovery of topological information from each neutrino interaction, i.e. images of the space and time pattern of an event, and enhances a detector’s event identification capability. It is difficult to segment finely enough to resolve the full topological information of individual events at these low energies without introducing certain disadvantages, such as dead material, radioactivity, cost, etc

Methods

Results

Conclusion