Development of an Ultra-Low-Temperature 5-Stage Continuous Adiabatic Demagnetization Refrigerator That Provides Cooling at Two Unique Temperatures

The cryogenics group at NASA-Goddard has built several adiabatic demagnetization refrigerators (ADRs) for cooling detectors to sub-Kelvin temperatures in a lab, balloon, or space environment. The effort presented here describes the development of a new 5-stage adiabatic demagnetization refrigerator capable of providing continuous cooling at 35 mK with a cooling power double that previously demonstrated at this temperature. It will also provide a separate continuous temperature platform near 1 K. This system will be qualified using flight-like conditions, culminating in an ADR that is ready for the rigors of spaceflight by the end of the effort.