Long-term monitoring of neutron and gamma backgrounds in the DANSS project

Precise measurements of neutron and gamma backgrounds, as well as their long-term continuous monitoring in reactor experiments aimed to search for oscillations into sterile neutrinos, are critical for reliable measurements. A unique feature of the DANSS project is the presence of an independent system of detectors (DBCS - DANSS Background Control System) that continuously register the gamma and neutron backgrounds inside and outside the shield of the DANSS spectrometer.
 This work presents the results of the analysis of data accumulated by the DBCS for more than four years. The structure and long-term temporal dynamics of neutron (thermal and fast separately) and gamma backgrounds of the DANSS spectrometer are analyzed depending on the location of the detector and thermal power of the reactor. The stability and expected low level of gamma and neutron backgrounds inside the DANSS shield are shown. The obtained results confirm that the DANSS passive shield works reliably within the claimed characteristics, which confirms the fidelity of the physical results obtained by the DANSS spectrometer.