The Double Chooz antineutrino detectors

TL;DR

The Double Chooz experiment's antineutrino detectors successfully measured neutrino oscillation parameters, demonstrating innovative detector design, background rejection, and high stability, influencing future neutrino detection efforts.

Contribution

This paper details the design, implementation, and performance of the Double Chooz detectors, introducing technological advancements and background rejection techniques for neutrino measurement.

Findings

Effective background rejection achieved

High detector stability and radiopurity

Influenced subsequent antineutrino detector designs

Abstract

This article describes the setup and performance of the near and far detectors in the Double Chooz experiment. The electron antineutrinos of the Chooz nuclear power plant were measured in two identically designed detectors with different average baselines of about 400 m and 1050 m from the two reactor cores. Over many years of data taking the neutrino signals were extracted from interactions in the detectors with the goal of measuring a fundamental parameter in the context of neutrino oscillation, the mixing angle {\theta}13. The central part of the Double Chooz detectors was a main detector comprising four cylindrical volumes filled with organic liquids. From the inside towards the outside there were volumes containing gadolinium-loaded scintillator, gadolinium-free scintillator, a buffer oil and, optically separated, another liquid scintillator acting as veto system. Above this main detector an additional outer veto system using plastic scintillator strips was installed. The technologies developed in Double Chooz were inspiration for several other antineutrino detectors in the field. The detector design allowed implementation of efficient background rejection techniques including use of pulse shape information provided by the data acquisition system. The Double Chooz detectors featured remarkable stability, in particular for the detected photons, as well as high radiopurity of the detector components.