Top-Loading 4He Sorption Refrigerator
摘要
We describe a newly developed top-loading 4He sorption refrigerator. The top-loading configuration allows for rapid sample exchange, efficient cooling, and modular probe construction. A prototype comprises a condenser, an evaporator, a charcoal adsorption pump, and a top-loading probe, precooled by a Gifford–McMahon cryocooler. The base temperature and hold time in single-shot mode are 0.95 K and 2.5 h, respectively. The prototype provides a useable cooling power of 1.85 mW at 1 K.