Haolin Sun
Abstract A soft-sealed cryogenic refrigeration scheme enabling synchronous vibration-cryogenic coupled measurement is proposed, alongside an innovative bidirectionally buffered soft-sealed structure. An integrated cryogenic-vibration coupling system is established, which integrates a G-M cryocooler, soft-sealed vibration coupling, vacuum thermal insulation, high-precision temperature control, and measurement calibration modules. Through thermal load evaluation and numerical simulation of structural heat transfer for the system, the cooling capacity transmission characteristics and temperature fluctuation attenuation law of the system are elucidated. An experimental platform is built to validate the thermal insulation performance, mechanical properties, temperature control accuracy, and vibration transmissibility of the system. Experimental results demonstrate that the core vibration zone of the system can be stably cooled to below 20 K, with a maximum temperature difference of only 0.0068 °C between the left and right measurement points in this core zone. The steady-state temperature fluctuation at each characteristic temperature point (20 K, 77 K, 120 K, 298 K) is ≤ 0.1 °C. The first-order vertical natural frequency of the vibration connecting rod is increased to 2355.4 Hz, which effectively avoids resonance with the excitation frequency band. The vibration transmissibility of the system at 20 K over the 20 Hz to 2000 Hz frequency range reaches 0.95 to 1.14, achieving the dual goals of high-fidelity vibration transmission at extreme cryogenic temperatures and superior vacuum tightness of the entire system.