Speaker
Description
To date, many experiments in the field of reactor antineutrinos show a discrepancy between the predicted antineutrino spectrum and the measured one. Therefore, the problem of reconstruction of the antineutrino spectrum seems so actual. It is possible to compare the measured and predicted spectra of positrons and not solve the inverse problem which requires a complicated unfolding procedure. However, this makes it difficult to compare positron spectra between different experiments, simply because each experiment has its own unique detector. By solving the inverse problem, we remove the contribution from detector response and obtain a pure antineutrino spectrum.
DANSS is a one cubic meter highly segmented solid scintillator detector. It consists of 2500 scintillation strips covered with gadolinium loaded reflective coating and read out with SiPMs and PMTs via wavelength shifting fibers. The antineutrinos are produced by a 3.1 GW industrial reactor at the Kalinin NPP (Russia). The process of inverse beta decay (IBD) is used to detect antineutrinos. DANSS detects about 5000 IBD events per day (in the position closest to the reactor core), with a few percent of the background induced by cosmic muons and fast neutrons.
The positron energy spectra are unfolded to obtain the antineutrino energy spectra with the SVD and Bayesian unfolding techniques. To check the correctness of the methods used, it is proposed to first unfold artificially generated positron spectra. The Huber-Muller model is used to generate antineutrino spectra. The positron spectra are obtained using a Monte-Carlo simulation of the passage of an antineutrino through the detector. Moreover, the systematic uncertainties in the unfolding process are carefully studied and quantified. As a result, the estimated accuracy of antineutrino energy spectrum reconstruction will be presented.
