Spin-Polarizing Concentrated ³ He- ⁴ He Mixtures by the Rapid-Melting Method

Abstract

We have achieved high-spin polarizations in concentrated mixtures of 3He in 4He using the rapid-melting method originally suggested by Castaing and Nozières for pure 3He. Polarizations well above the equilibrium value (greater than 10%) were obtained at T ≈ 350 mK. The observed relaxation time T1 = 4000 s was of the same order as the theoretical predictions of the bulk relaxation time, and was long enough to suggest that it should be possible to study the properties of these strongly polarized mixtures.