Speaker
Description
DANSS is a solid state scintillation detector of reactor antineutrino,
placed just below 3.1 GW industrial light water reactor of Kalininskaya Nuclear
Power Plant about 350 km NW from Moscow. A cubic meter sensitive volume of
the detector is formed by 2500 scintillator strips with individual SiPM
readout. Groups of 50 strips are also readout by conventional PMTs.
Reactor antineutrinos are detected by inverse beta-decay (IBD).
The sensitive volume has passive shielding of copper (5 cm), borated
polyethylene (two layers of 8 cm), lead (5 cm) and active shielding of
double layer scintillation counters. The position below reactor
provides overburden about 50 m.w.e. A movable platform of the detector
allows to change its distance to the reactor from 10.7 to 12.7 m
(center to center). 5000 IBD events are detected daily in the
position closest to the reactor.
Ratio of the antineutrino spectra at different distances measured
with the DANSS detector is sensitive to neutrino oscillations to sterile
neutrinos in the most interesting region of the oscillation parameters
space (delta m squared ~ 1 eV^2), where the effect is suspected
by Gallium and Reactor antineutrino anomalies. The DANSS collaboration
presents results of 1.5 year detector running with three positions
(10,7, 11.7 and 12.7 m) cycled weekly. The talk covers sterile neutrino
search results as well as analysis details.