Optimum structure of multilayer regenerator with magnetic materials

✍ Scribed by T. Tsukagoshi; K. Matsumoto; T. Hashimoto; T. Kuriyama; H. Nakagome

• Book ID: 104111215
• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 361 KB
• Volume: 37
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/s0011-2275(96)00086-0

✦ Synopsis

We investigated a layered structural regenerator (multilayer regenerator) with magnetic regenerator materials using a two-stage GM refrigerator. In this study we used Er0.75Gd0.25Ni which was expected to be placed in the high temperature part of the second regenerator.

To confirm the effect of Er0.75Gd,,25Ni, the heat-exchange efficiency of the regenerator (regenerator efficiency) with Er0.75Gd0.25Ni, Er,Co and ErO.sYbO.,Ni, which were in the volumetric ratio x: (0.5 -x): 0.5 (0 zz x I 0.5) was calculated as a function of x by computer simulation.

We found that the regenerator efficiency increased when x (i.e. the amount of Er0.75 Gd,,25Ni) was increased and an optimum value of x was -0.25. We then made two kinds of second regenerator: a triple layer regenerator with Er0.75 Gd,,25Ni, Er,Co and ErO,gYb,.,Ni, which were in the volumetric ratio 0.25:0.25:0.5, and a double layer regenerator with Er,Co and Er,,sYb,,,Ni, which were in the volumetric ratio 0.5:0.5. We compared their refrigeration performances experimentally.

With the triple layer regenerator, the lowest temperature was 2.60 K at the second stage and the maximum refrigeration capacity at 4.2 K was 1.17 W. These results were superior to those with the double layer regenerator.