CRYOCOOLER RESONANCE CHARACTERIZATION

An important issue in the design and scaling-up of Stirling cryocooler s is achieving good drive motor efficiency and launch survivability. T he important common thread linking these two topics is the dynamic res onant response of the compressor and displacer moving masses. The fund amental equations governing cryocooler mechanical efficiency and launc h vibration response are presented and explored in terms of their impl ications for cooler design. The resonant frequency, damping and drive motor force parameters associated with the cooler are shown to be key to efficient operation. Means of measuring these parameters are presen ted and shown to have broad applicability to additional parameters suc h as drive stiction and vibration transmitted to the instrument. The r esonant parameters of the BAe 55 K AIRS proof-of-concept cooler are us ed as an example to demonstrate the good correlation between the analy tical fundamentals and the measured characteristics of a state-of-the- art cryocooler design.