ИСТИНА

The second comprehensive calibration campaign of the Borexino detector will be performed before the third upcoming phase of the experiment devoted verification the hypothesis of the existence of sterile neutrinos. Since Borexino is a multipurpose detector the energy scale will be constructed in wide range from a few hundred keV up to several dozen MeV. It plans to determine and characterize the detector response at energies below 10 MeV with radioactive sources (for example, 241Am9Be, 222Rn, 68Ge-Ga, among others) while the controllable UV LED flasher will be applied to calibrate the Borexino detector at energies above 10 MeV. The poster covers the second aspect describing the UV LED calibration system and the corresponding experimental method. The calibrations above 10 MeV are necessary in order to detect neutrinos from astrophysical sources such us supernovae. The capabilities and features of the flasher are considered. Also additional researches like a pile-up analysis are possible. The research was supported by the grant of the Russian Science Foundation (project № 16-12-10369).