Basic pulse-tube refrigerator in the narrow limit

The basic pulse-tube refrigerator is studied using near-isothermal theory. The entropy flux is evaluated. This allows for dividing the enthalpy flux into heat and work at the extremities of the tube, yielding a full performance characterization. Except for a simple numerical integration at the end, the study proceeds entirely in closed form, so that an investigation of the complete parameter space can be performed fairly easily. The basic pulse-tube is inherently irreversible, so that its coefficient of performance is limited to values lower than the Carnot limit; according to the results, coefficients of performance greater than 50% of the limit are possible, but for relatively small temperature differences, outside of the cryogenic range. In view of the simplicity of the device, it might find some use in the low lift refrigeration range