COLD STORAGE MATERIAL AND COLD STORAGE REFRIGERATOR

摘要

PROBLEM TO BE SOLVED: To provide an inexpensive cold storage material in which cryogenic temperature lower than 4K can be attained. SOLUTION: The final layer 13c of a displacer 13 on the final stage of a multistage Gifford-McMahon type refrigerator is filled with spherical active carbon 14. Helium gas (He) exhibiting specific heat higher than that of holmium copper (HoCu2 ) in a cryogenic temperature region of 10 K or below is adsorbed to the fine pores of the active carbon 14 as a cold storage material. Since an active carbon 14 exhibiting higher workability than rare earth elements or rare earth compounds at lower cost is employed as a cold storage material along with helium gas (He), cryogenic temperature of 4K or below can be attained using an inexpensive cold storage material.