Progress of xenon liquefaction technology by using a pulse tube cryocooler

Application of a pulse tube cryocooler to liquefy and keep liquid xenon temperature instead of using liquid nitrogen is introduced. At first, a commercially available 80 K small pulse tube cryocooler was applied to demonstrate xenon liquefaction. The cooling power at 165 K was measured as about 14 W. The development of a high power pulse tube cryocooler has been carried out at KEK for use in cooling the large volumes of liquid xenon. The measured cooling power of the KEK-cryocooler was 70 W at 165 K. Then, the KEK-cryocooler technology was successfully transferred to Iwatani Industrial Gases Corp (IIGC) for manufacturing more powerful cryocoolers. In this paper, the finally obtained performance data around 200 W at 165 K is presented. More details of the application of high power cryocoolers to various experiments are also given.