Performance of the pulse-tube cryocooler: Theoretical model and experimental results

The pulse-tube is a relatively new device in the field of cryogenics. In the last two decade a good theoretical understanding has been developed of various types of pulse-tubes, but there is still no good methodology for constructing/designing an efficient, reliable and commercially attractive pulse-tube. Our research group has designed, built and laboratory tested an orifice pulse-tube with a by-pass. Currently our pulse-tube can reach temperatures of 65K with no load, and provides 0.5 Watts of refrigeration at 80K. Experiments show that the by-pass has a notable effect on the pulse-tube performance, and lowers the freezer temperature by 10K to 20K. To aid with understanding of how various design parameters influence the pulse-tube performance, we have developed an analytical model and compared its results with experimental data. The analytical model exhibits the same qualitative trends observed from experiments and hopefully will prove useful in optimizing the pulse-tube.