Effect of High Entropy Magnetic Regenerator Materials on Power of the GM Refrigerator
In previous work we have proved that heavy rare earth compounds with low magnetic transition temperature Tc are very useful as regenerator materials in low temperature range. Applying the magnetic material Er3Ni particles to the 2nd regenerator of the GM refrigerator, we were able to reach the 2 K range but could not obtain high refrigeration power at 4.2 K. This is thought to be due to the temperature dependence of the magnetic specific heat.
We present here a method by which high refrigeration power is obtained at low temperature. The simplest means of obtaining high power is with a hybrid structure regenerator which is composed of two kinds of magnetic materials, high Tc and low Tc materials. Computer simulation and experiments were carried out to verify the superiority of the hybrid regenerator. We succeeded experimentally in obtaining the high power of ~1.1 watt at 4.2 K. We will report other detailed results and discuss developing way of the magnetic regenerator in future.
KeywordsMagnetic Entropy Change Magnetic Regenerator Regenerator Material Double Layer Regenerator Cryogenic Engineer
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