Measurement of neutrino source activity in the experiment BEST by calorimetric method

Experiments to study non-standard properties of neutrinos using high-intensity artificial neutrino sources require high accuracy in determining their activity. A calorimetric system to determine the activity of a 51Cr neutrino source in the experiment BEST with an accuracy better than 1% was created. The design of the calorimetric system and the main factors affecting the accuracy of measurements are considered. The results of measurements of the activity of the source made for the BEST experiment are presented. The value of the source activity from calorimetric measurements was 3.41 MCi at the beginning of the experiment.