A pulsed NMR study of 3He-4He solutions

The authors report a study of the Leggett-Rice effect in dilute 3He-4He solutions at a Larmor frequency of 71 MHz. They measured the height and phase of the spin echoes following 2-pulse NMR sequences of three solutions with 3He concentrations of 0.56%, 1.4%, and 4.0%. The theory of Leggett fits the data extremely well and yields values of the parameter μM0 and the transverse diffusion coefficient D. The authors are also able to evaluate μM0 and D by analyzing multiple spin echoes and find good consistency between the two methods. From values of λ/(1 + F0a) at various concentrations, they are able to determine the scattering length for 3He quasiparticles, a, quite accurately. They find a = -0.97 ± 0.03 angstrom