Investigation of a single-stage G-M refrigerator with high cooling capacity for HTS devices

Publisher Summary This chapter summarizes the experimental work of single-stage G-M refrigerators. Since conventional single- stage G-M refrigerators cannot reach the temperature below 20 K, they cannot provide the high cooling capacity at 30 K. At the same time, the conventional double-stage G-M refrigerators have a lowest temperature of the second stage, about 7 K. However, they are not efficient in the temperature range of 30–50 K. Therefore the conventional single- and double-stage G-M refrigerators cannot achieve the goal of cooling HTS devices. Because the cooling of HTS device needs the cryogenic refrigerator working at 30 K, and the investigation of HTS devices are more and more considerable, the requirement for the G-M refrigerator with the cooling capacity of 50 W/30 K increases gradually. But there is no any product of the G-M refrigerator that can meet the request of cooling HTS device. At present, the lowest temperature of 17 K operating at 1 Hz has been achieved. The cooling capacity of 27 W has been obtained at 30 K.