# Neutrinos Angra experiment: commissioning and first operational measurements

## TL;DR

The Neutrinos Angra experiment successfully commissioned a water-based detector system at a nuclear power plant to detect reactor antineutrinos, demonstrating operational readiness and initial measurement capabilities.

## Contribution

This paper reports the first operational measurements and detailed detector assembly of the Neutrinos Angra experiment, a novel water-based neutrino detection setup at a nuclear site.

## Key findings

- Detector fully assembled and commissioned
- Initial measurements demonstrate detector functionality
- Operational characteristics align with design expectations

## Abstract

The Neutrinos Angra Experiment has completed a major step by finishing the comissioning of the detector and the data acquisition system at the experimental site located in the Angra dos Reis nuclear power plant. The experiment consists of a water-based detector and associated electronics, both designed with the goal of detecting the electron antineutrinos produced by the nuclear reactor. The detection is possible due to the Inverse Beta Decay, where the final products in the water are photons in the UV-to-visible range of the spectrum. The assembled detector comprises three active volumes filled with water: (i) a cubic target detector for electron antineutrinos, covered by 32 8-inches PMTs, (ii) a lateral layer surrounding the target (veto) equipped with 4 PMTs and (iii) a third volume covering the top of both, also equipped with 4~PMTs. In the present document the main features of the detector assembly as well as the integration of the readout electronics on-site are reported. Finally, some operational characteristics are shown based on straightforward analysis of the first measurements performed during the last months with the fully working detector.