Thermal stabilization system for a multi-element scintillation screen

A thermal stabilization system for a multi-element scintillation screen consisting of bismuth orthogermanate BGO crystals has been developed and tested. Thermal stabilization is necessary to improve the energy resolution of the screen, since the light output of the crystals depends on temperature. The main characteristics of the system are measured, such as the time of cooling the screen to the required operating temperature, long-term stability and uniformity of temperature distribution over the screen. The effects of changes in environmental conditions or malfunction of individual elements of the thermal stabilization system on the stability and uniformity of the screen temperature is investigated. It is shown that the thermal stabilization system provides high long-term stability and temperature uniformity with an accuracy of $\pm$0.05$^\circ$C, which made it possible to obtain an energy resolution of the screen of 0.5%.