Cryogenic systems in MuSun experiment.

Refrigeration systems of the main detector and preamplifiers in the MuSun experiment are described. The systems are developed and built at Cryogenic Superconductive Techniques Laboratory (CSTD) of St. Petersburg Nuclear Physics Institute (PNPI), Gatchina, Russia. A neon heat pipe driven with a helium cryogenerator is utilized for the cooling of the main detector. Second system uses liquid nitrogen cooling. Temperature stabilization for both facilities is established by a balance of the cooling power of corresponding cooling facilities and their electric heaters. The cooling and temperature stabilization is regulated by a microprocessor controller. Basic technical features of the installations are discussed. An application of described technical solutions for a perspective PolFusion experiment is proposed.