A simple model for a superfluid stirling refrigerator at high operating temperature

The superfluid Stirling refrigerator (SSR) is a Stirling machine that uses the ideal gas behavior of rite He-3 Component of a He-3-He-4 mixture to pro vide cooling at temperatures below 2 K, The design of SSR's to date has use d the Schmidt model to predict the performance of a given machine. Unfortun ately, rite Schmidt model does not account for the phonon and roton excitat ions present in He-4 component of the mixture, These excitations significan tly change the performance of the SSR. An analytical model of the SSR that accounts for the phonon and roton excitations is presented. High temperatur e SSR experimental data is also presented and found to compare well with th e model.