Realization of Temperature Environment below 1 K Using a Compact GM Refrigerator

Abstract

  In this article, we describe the method attaining low temperatures below 1 K using a commercial compact GM refrigerator. The main part of this system consists of 4 K plate attached to the second cooling stage of GM refrigerator, 1 K pot and ³He pot, which are covered with three radiation shields attached to the first stage of GM refrigerator, 4 K pot and 1 K pot. The required time to reach temperatures below 1 K is within 6 hours, and temperatures below 0.5 K can be maintained for more than one day by one-shot operation. This system can be applied to terahertz industry as well as low temperature physics.