Moscow International School of Physics 2020

DANSS is a one cubic meter highly segmented solid scintillator detector. It consists of 2500 scintillator strips, covered with gadolinium loaded reflective coating and read out with SiPMs and PMTs via wavelength shifting fibers. DANSS is placed under a 3 GW industrial reactor at the Kalinin NPP (Russia) on a movable platform. The inverse beta decay (IBD) process is used to detect antineutrinos. DANSS detects about 5000 IBD events per day with the background from cosmic muons at the level of a few percent. Antineutrino energies are determined from the IBD reaction by measuring energies of produced positrons, therefore the energy scale accuracy is a key parameter for the data analysis. We use two processes caused by stopped muons in order to determine the energy scale. Muon and anti-muon decays at rest provide electrons and positrons with energies up to 53 MeV. The second process is a beta decay of borum produced in stopped muon's capture on carbon: $\mu^- + \ ^{12}C \ \rightarrow \ ^{12}B + \nu_\mu$. The borum beta decay electron energy spectrum ranges up to 14 MeV. In the talk we describe a method of identification of muons stopped inside the central cube of the detector and present selection criteria for studied reactions. The measured electron and positron energy spectra from the two studied processes are compared with the results of the Monte Carlo simulations in order to determine the corrections to the energy scale and the additional blurring coefficient, required to describe the experimental data.