Orateur
Prof.
Mikhail Danilov
(NRNU MEPhI and LPI (Moscow))
Description
DANSS is a one cubic meter highly segmented solid scintillator detector.
It consists of 2500 scintillator strips (100x4x1 cm3), covered with
gadolinium loaded reflective paint and read out by SiPMs via wave length
shifting fibers. Groups of 50 strips are also read out by conventional
PMT. DANSS is placed under a 3 GW reactor at the Kalinin NPP (Russia) on a
movable platform. The distance from the reactor core center can be changed
from 10.7m to 12.7m. The core and other materials provide about 50 mwe
shielding against cosmics, which reduces the background drastically. DANSS
started data taking in April 2016. The first results based on 27 days of
data taking demonstrated that DANSS detected about 5000 IBD events per day
with the background from cosmic muons of about 5%. In June, the data
taking was stopped, in order to repair a water leak. The data taking with
regular movement of the detector was resumed in October. The results
based on more than 4 months of data taking will be presented including reactor off periods.
The Neutrino-4 experiment searches for sterile neutrinos at the SМ-3 nuclear
reactor (Dimitrovgrad, Russia). This 100MW reactor has a very compact core
of 35×42×42 сm3. The prototype of a multi-section neutrino detector with
liquid scintillator volume of 350 l was installed in the middle of 2015. Measurements with the full-scale detector with liquid scintillator volume of 3 m3 (5x10 sections) were started in June, 2016. Detectors are movable inside the passive shielding within a range from 6 to 12 meters from the reactor core. Measurements of antineutrino flux at such short distances from the reactor core are carried out with a moveable detector for the first time. The main difficulties of the measurements are due to large cosmic background, which decreases the precision of measurements. Analysis of measurements at small distances together with the data obtained at long distances is performed in order to obtain parameters of sterile neutrino.
Summary
Results of the DANSS and Neutrino-4 experiments on searches for sterile neutrino are presented
Author
Prof.
Mikhail Danilov
(NRNU MEPhI and LPI (Moscow))
