ADR Magnets Operating at 30-40K, Phase II

Currently many commercial superconducting magnets use Nb-Ti or Nb3Sn wires and are cryogen-free. These magnets use commercial cryocoolers that can achieve cooling capacity of 0.5-3 W at 4-10 K. The input power requirement of these expensive cryocoolers range between 3-5 KW, and they can weigh in access of 100 Kg. Magnets fabricated with HTS wires/tapes that operate at 30-40 K can be operated by simple and less expensive single-stage cryocoolers. This breakthrough technology will have a significant impact on efficiency of superconducting magnets used in motors, actuator, imaging devices, high-power electric propulsion, and detectors with potential use in space applications. Many next generation satellite detectors and space telescopes require detectors to be cooled to temperatures of below 0.1 K. Adiabatic Demagnetization Refrigerators (ADRs) offer a practical approach to achieving such low temperatures. Present ADRs operate at 4-10 K requiring substantial cryocoolers. If an ADR system could reject its heat at about 30 K or above, the approach of passive radiative cooling can come into serious consideration whereby mechanical cryocoolers can be totally removed from the overall cooling system. This can be a significant breakthrough that opens the door to a wider application of ADRs in space application, as well as other superconducting magnets in space in general. More »