A new strategy for achieving multiple continuous cooling stages in an adiabatic demagnetization refrigerator

TL;DR

This paper introduces a novel three-stage continuous adiabatic demagnetization refrigerator design that simplifies system complexity while providing multiple cooling stages at different temperatures, with significant performance achievements.

Contribution

It presents a new strategy for multi-stage continuous cooling in CADR systems without extra stages, reducing complexity and mass.

Findings

Achieved 20 μW cooling power at 1 K

Achieved 4 μW cooling power at 300 mK

Successfully demonstrated simultaneous multi-temperature cooling

Abstract

This paper presents a three-stage continuous adiabatic demagnetization refrigerator (CADR) simultaneously providing cooling platforms at two different temperatures. Unlike conventional CADR with two continuous stages, this system does not require an extra continuous stage. It is achieved with carefully designed heat switch operations and stage sequences. This new strategy significantly reduces system complexity and mass. The detailed implementation of the two cooling platforms is described, and factors limiting system performance are analyzed. This CADR system has achieved a cooling power of 20 {\mu}W@1 K and 4 {\mu}W@300 mK simultaneously, offering a new design strategy for the development of CADR with multiple continuous stages.