Polarized liquid {sup 3}He in a {sup 4}He circulating dilution refrigerator

Journal Article · Sun Oct 01 04:00:00 EDT 1995 · Journal of Low Temperature Physics

DOI:https://doi.org/10.1007/BF00754571· OSTI ID:198166

Rodrigues, A; Vermeulen, G ^[1]

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1. l`Universite Joseph Fourier, Grenoble (France)

We have used a {sup 4}He circulating dilution refrigerator to produce cold liquid {sup 3}He with a steady state out-of-equilibrium nuclear spin polarization. Polarizations on the order of 15% (more than 7 times higher than the equilibrium polarization in the external field of 6.6 T) have been obtained in the mixing chamber of the refrigerator at temperatures between 10 and 15 mK. The polarization is enhanced at high pressure because the molar susceptibility of concentrated {sup 3}He is larger than that of the dilute phase. The polarization exchange between the dilute and concentrated phases (in direct contact in the heat exchanger of the refrigerator) amplifies the enhancement. The polarization diminishes below a pressure of 2.6 bar. This allows us to scale and reinterpret susceptibility data of the dilute phase in combination with the effective mass deduced from osmotic pressure measurements. We find 1+F{sub 0}{sup a}=0.89 {plus_minus} 1% on the phase separation line in the pressure range 0-20 bar.

• Sponsoring Organization: USDOE
• OSTI ID: 198166
• Report Number(s): CONF-950676--
• Journal Information: Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 1-2 Vol. 101; ISSN JLTPAC; ISSN 0022-2291
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
HELIUM 3
HELIUM 4
HELIUM DILUTION REFRIGERATION
SPIN ORIENTATION
TIME DEPENDENCE