| 摘要 |
PURPOSE:To enhance refrigerating capacity near a temperature of liquid helium by charging first cold storage material and second cold storage material in a cold accumulator disposed at a final stage. CONSTITUTION:A cold storage material 22 is contained in a first displacer 18, and a cold storage material 24 is contained in a second displacer 19. The material 24 has a cold storage element 24a filled at a high temperature side and a cold storage element 24 b filled at a low temperature side. The element 24a is represented by a formula (Er(x)R(1-x))3Ni(y)Co(1-y) (where 0<=x<=1, 0<=y<=1, R is a rare earth element selected from Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Tm, Yb, Sc, while the element 24b is represented by a formula Er(x)R(1-x)Ni(y) Co(1-y) (where 0<=x<=1, 0<=y<=1, R is a rare earth element selected from Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Tm, Yb, Sc. Accordingly, refrigerating capacity can be improved near a temperature of the liquid helium. |
