Nuclear cooling.

Thermal contact between a metal and liquid 3He at temperatures of a few mK can be greatly enhanced by adding a small proportion of magnetic impurities to the metal. This important experimental effect has been demonstrated by Avenel, Berglund, Gylling, Phillips and Vetleseter of the Helsinki University of Technology, working in collaboration with Vuorio of the University of Helsinki (Phys. Rev. Leu., 31, 76; 1973)