A He3/He4 dilution refrigerator for Mössbauer experiments at very low temperatures

✍ Scribed by G.J. Ehnholm; T.E. Katila; O.V. Lounasmaa; P. Reivari

• Publisher: Elsevier Science
• Year: 1968
• Tongue: English
• Weight: 756 KB
• Volume: 8
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(68)90088-x

✦ Synopsis

A L L M/3ssbauer experiments at low temperatures published so far have been performed in cryostats in which liquid He 4 is the ultimate cooling agent. An early exception was the investigation of nuclear polarization of Co 5v in iron by Taylor l and his colleagues down to 0.35°K in a He 3 refrigerator. Quite recently Ono, Shinohara, Ito, Fujita, and lshigaki: have studied FeClz.4H20 between 4.2°K and 0.025°K using magnetic cooling to reach the lowest temperatures. Adiabatic demagnetization techniques, however, are not very suitable for M/Sssbauer work because a 'one shot' method cannot satisfactorily cope with the rather long counting times and the relatively large heat leaks normally encountered in these experiments. With the recent advent of the He3/He 4 dilution refrigerator (Hall, Ford, and Thompson? Neganov, Borisov, and Liburg, 4 and Vilches and Wheatley s) a new and