The displacer in a two-stage Stirling cooler should prevent gas leakage between the compression space at room temperature, the first stage expansion space, and the second stage expansion space. To achieve this, clearance seals are usually required at two locations between the displacer and the cylinder. Through the geometric analysis, we discovered that if the displacer operates with a very...
Regenerative 4 K cryocoolers, such as Gifford-McMahon (G-M) and G-M type pulse tube cryocoolers, have been required for superconducting applications. A problem with these cryocoolers is the low efficiency to achieve the attainable temperature of 4 K. An electrical input of 6-7 kW is required to achieve a cooling capacity of one watt level at 4 K. To solve this problem, a new operating method,...
Cryocoolers are an excellent go-to solutions when cryogen-free dry cooling is essential. The existing cryocoolers in the market are certified with the cooling capacity specified only at generic points (such as 4.2 K, 10 K and 20 K). However, if the cryorefrigeration is to be obtained in any other cryogenic temperature range, the cryocooler capacity is not readily available. It is indeed...
The rapid advances in quantum technologies have significantly increased the demand for reliable cryogenic refrigeration systems capable of cooling quantum devices. Quantum device requires a temperature level of 10-20 mK and quiet environment, because the entanglement of the superconducting qubit may not be sustained due to thermal fluctuations and mechanical vibration. This phenomenon is...
Gas-coupled type multi-stage high-frequency pulse tube cryocoolers (HPTCs) whose different stages are coupled directly through mass flow offer unique advantages in terms of compact structure and small volume and weight, leading to significant application prospects in special fields such as deep space exploration. However, limited by the subtle intrinsic interaction of gas proportion and energy...
