抄録
Pulse tube cryocoolers are more attractive than other small cryocoolers because they have no moving parts in the expander and thus have higher reliability. Especially, Stirling type pulse tube cryocooler needs further improvement on regenerator. The working gas flow in the regenerator has non-uniform velocity distribution with the expansion and contraction flow. They cause the excessive pressure loss and reheat loss. The effect of the regenerator entrance shape on the performance of U shape pulse tube cryocooler was examined experimentally. So, the effect of cold-head end was bigger than that of after-cooler end.
