Measurements of the reactor antineutrinos with the DANSS experiment

Abstract

The detector of the reactor antineutrino DANSS is placed on a movable platform below a 3.1 GW industrial reactor of Kalininskaya Nuclear Power Plant. The sensitive volume of the detector is a cubic meter of plastic scintillator assembled from 2500 strips with dual readout by Silicon Photo Multipliers (SiPM) and conventional PMTs (in groups of 50 strips). The detector position provides simultaneously a high neutrino flux and an overburden of about 50 m.w.e., resulting in a high counting rate of inverse beta-decay events and cosmic muons induced background as low as 1.9%. The distance between the reactor core and the detector is changed in a week cycle through three positions 10.7, 11.7 and 12.7 m. This allows systematic-free comparison of the antineutrino spectra measured at different distances by the same detector.This article presents results of the 2.5 year of data collection with more than 2 million of neutrino events collected.