Custom-built research refrigerators for ultra-low temperature

The Janis line of ultra-low-temperature research refrigerators is presented. Cryogen-containing and cryogen-free 3He, 3He–4He dilution and adiabatic demagnetization refrigerators for the mK temperature range are described in detail and their possible use for cooling low-temperature sensors and detectors is discussed. A special emphasis is made on the Janis temperature scale down to 10 mK, maintained with a newly designed compact CMN thermometer and superconducting fixed point device.