Home > Proceedings of the 14th International Cryocooler Conference > Yang

Abstract

In the past several years, we have investigated two-stage high frequency pulse tube coolers (PTC) for operation at 20 K to 40 K by simulation and experiment. Initially, a computer code, based on a thermal physics method, was developed to optimize the geometrical parameters of our first u-tube two-stage PTC, built and tested at the University of Giessen. In 2003, this PTC achieved the lowest temperature of 19.6 K with a 250 W electrical input, using a stainless steel mesh for the regenerator material. Here, we report on further tests conducted with this cooler. The experiments use lead spheres of different size or lead-plated mesh in the 2nd regenerator and then by use of a larger 2nd-stage pulse tube. There is no evident improvement in the cooling performance by the use of the lead materials. With the larger pulse tube, the refrigeration temperature has been reduced and the cooling capacity has been increased. A new version of this PTC with a coaxial configuration for the 1st stage was built at CAS Beijing. It resulted in a low temperature of 16.1K with 250 W electrical input power.