Estudo da qualidade e estabilidade dos dados do experimento ѵ-Angra

Abstract

The Neutrinos Angra experiment aims to measure the dissipated power in the Angra II reactor by reading the flow of antineutrinos released in the process of burning nuclear fuel and detect any emission of anomalous radiation that may occur around the reactor facilities for the purpose of Nuclear safeguards. For this purpose, a particle detector based on gadolinium-doped water equipped with 40 photomultipliers was designed and developed to read the light signals left by the particles that interact inside it. In addition to the detector, a complete system was developed, comprising electronics for reading and acquiring signals (one reading channel per photomultiplier tube), control modules and data storage. The detector has been operating at the Angra II site since the second half of 2018. Its acquisition system, after installed, required tools to help adjust parameters, understand its characteristics and monitor it in order to guarantee the quality of the data collected over the years. In this context, this Dissertation aimed to propose important tools in order to assist in the tuning of fundamental parameters of the system, such as the thresholds of the discriminators of the electronic reading channels, used to detect when a photomultiplier tube is hit by an event, and the gains of the photomultipliers tubes, in addition to providing parameter monitoring tools, for the pedestal, the waveform of the signal and the energy distribution of each channels. The data collected during 2019, 2020 and 2021 were analyzed and the periods of stability/instability of the detector identified.