PT410 Cold Head dynamic characterization

Abstract

In the design of cryostats that use cryocoolers, the characterization of the cryocooler is crucial for vibration-sensitive applications. This study focuses on the PT410 pulse tube cryocooler from Cryomech, using modal and microvibration testing. Modal testing examined the natural frequencies and vibration modes of the cold head. Microvibration testing determined the interface forces caused by the cryocooler’s operation on the mechanical mounting interface and the accelerations induced on the thermal interface of the cold stages. The first bending modes of the cryocooler were identified through modal testing. Forces were directly measured using triaxial load cells, and accelerations of the cryocooler stages were recorded with accelerometers. The characterization was performed on a test bench designed for precise measurements. The cold head of the cryocooler is supplied by a helium flow pulse, which introduces vibration. Consequently, an additional support was added for the supply line elements. This study characterizes the dynamic response and mechanical stability of the PT410 cold head based on measured data and testing results. These results are essential for the designing and developing of cryogenic systems where controlling vibrations is critical.