ADIABATIC DEMAGNETIZATION REFRIGERATORS FOR SMALL LABORATORY EXPERIMENTS AND SPACE ASTRONOMY

An overview is given of the general principles and techniques used for the design and construction of compact, portable adiabatic demagnetiz ation refrigerators (ADRs). The paper covers methods of salt pill susp ension, magnet technology, lead design, heat switches and temperature readouts, as well as considerations for space qualification. Performan ce specifications are given for an ADR which was originally developed for cooling infrared detectors on the Space Infrared Telescope Facilit y (SIRTF). This ADR is presently used on the balloon-borne Millimeter Wave Anisotropy Experiment (MAX) for measuring anisotropy in the cosmi c microwave background. Comparisons are made with other ADRs under dev elopment for use in space or on rockets.