The experiments of a two-stage pulse tube cryocooler with pressed Er-plated screen as regenerator material

Abstract The regenerator is a crucial component in regenerative cryocoolers, responsible for providing cooling power through the heat exchange between helium and the regenerative materials within it. When the temperature drops below 20 K, the specific heat capacity of helium increases and surpasses that of the stainless steel, impeding the heat transfer process within the regenerator and limiting the enhancement of cooling power in cryocoolers operating at 20 K. To enhance the cooling power of a two-stage thermally-coupled pulse tube cryocooler functioning within the 20 K temperature range, this paper focuses on optimizing the regenerative materials. Stainless steel screens, Er-plated stainless-steel screens, and pressed Er-plated stainless-steel screens were used as regenerative materials. The parameters and experimental results of these materials were compared.