cryogenic equipment

An optical cryostat with ³Не sorption refrigerator is proposed. The refrigerator is mounted on a copper plate with temperature 4.2K in vacuum volume of helium cryostat. It has both sorption steps: the first with working gas ⁴Не is intended for condensation of ³Не, the second with ³Не for cooling down to 0.3K. The cryostat is an independent device that does not contain the external gas communications aimed at reaching low temperatures, and working gases are stored in cans integrated with the cryostat. The refrigerator can be used together with the cryocoolers of Gifford-McMahon or pulse tube types with cooling power not less than 0.3W/4K, thus allowing operating without any liquid cryoagents.