  A magnetic heat pump apparatus consisting of a solid magnetic refrigerant,
gadolinium, and a liquid regenerator column of ethanol and water has been
tested. Utilizing a 7T field, it produced a maximum temperature span of 80 K,
and in separate tests, a lowest temperature of 241 K and a highest temperature
of 328 K. Thermocouples, placed at intervals along the regenerator tube,
permitted measurement of the temperature distribution in the regenerator fluid.
No attempt was made to extract refrigeration from the device, but analysis of
the temperature distributions shows that 34 watts of refrigeration was
produced.
