A pulsed NMR study of sup 3 He- sup 4 He solutions

The authors report a study of the Leggett-Rice effect in dilute {sup 3}He-{sup 4}He 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 {sup 3}He concentrations of 0.56%, 1.4%, and 4.0%. The theory of Leggett fits the data extremely well and yields values of the parameter {mu}M{sub 0} and the transverse diffusion coefficient D. The authors are also able to evaluate {mu}M{sub 0} and D by analyzing multiple spin echoes and find good consistency between the two methods. From values of {lambda}/(1 + F{sub 0}{sup a}) at various concentrations, they are able to determine the scattering length for {sup 3}He quasiparticles, a, quite accurately. They find a = {minus}0.97 {plus minus} 0.03 {angstrom}.