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Description
This paper presents a review of the recent development of a variety of high-performance cryocoolers developed in the author’s laboratory with the operating temperatures ranging from 120 K down to 5 mK. Above 1.0 K, the refrigeration cycles involves both regenerative and recuperative cycles, and the hybrid cycle composed by the former two as well. For the regenerative cycle, the study is focused on the Stirling-type pulse tube cryocooler (SPTC) because it not only has no moving component at cold end, which eliminates any wear therein and minimizes vibration and EMI, but also is driven by the linear compressor which makes it further realize long life at warm end and achieve high system efficiency. The mature miniature and mid-sized single-stage SPTCs cover 25–120 K while multi-stage ones can achieve 3.3 K with cooling capacities varying from milliwatt levels to tens of watts. These SPTCs are mainly used to provide low-noise cooling for the infrared detectors with short, medium, and long wavelengths and the cold optics systems, and several types of them are developed for space applications. A high-capacity SPTC capable of 1220 W at 77 K has found applications in the high-Tc superconducting power systems such as HTS cables and dynamic synchronous condensers, and several SPTCs with the typical cooling capacity of 100 W at 20 K are used to cool high-Tc superconducting magnets in the controlled nuclear fusion system. The hybrid cryocooler, typically composed of the recuperative JT cryocooler precooled by the regenerative multi-stage SPTC, is developed to achieve the lower temperatures of 1–2 K. With a no-load temperature of 1.36 K and the effective cooling powers at 1.8 K, it is used to cool the superconducting nanowire single photon detector, which often plays an important role in the optical quantum computers. The cryogen-free dilution refrigerator is a rising development focus in the authors’ laboratory, which has a base temperature of 5 mK and the typical cooling powers varying from 400 μW to 1.3 mW at 100 mK, and is expected to provide appropriate cooling for the quantum chips in the superconducting quantum computers. In the latter development, either the multi-stage SPTC with the high cooling capacity at 3.0–4.2 K, or the hybrid cryocooler with the appropriate cooling capacity at 2.0–3.0 K, serves as the critical precooling stage for the dilution refrigerator. The application background, design philosophy and optimization approaches of the above various cryocoolers are described and summarized, and then the performance characteristics of them are presented and discussed.
Acknowledgements:
This work is supported by the National Natural Science Foundation of China (Grant No. 52076210), the Major Project of Science and Technology Commission of Shanghai Municipality (Grant No. 22511100100) and Shanghai Municipal Science and Technology Major Project (Grant No. 2019SHZDZX01).
| Submitters Country | China |
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