Spin Waves in Liquid HELIUM-3.

This dissertation describes measurements of collisionless spin waves in liquid ('3)He in the normal and superfluid A(,1), A, and B phases. The spin waves were measured by transverse cw NMR at the Larmor frequencies of 1, 2, and 4 MHz. The pressure range was varied from 0 bar to 12 bar. In the normal phase sharp peaks due to spin waves appear on the NMR line shape below 5 mK. These measurements were performed at several different field gradients. The experiment agrees quite well with a theory by Leggett (1970) and permits a determination of the Fermi liquid parameter F(,1)('a). Although spin waves were observed in the A(,1) phase, thus far there is no theory for their frequency and damping in this phase. In the A phase the spin waves were heavily damped except near T(,c). The peak frequency displays shifts which are not predicted by present theories. In the B phase the experiments agree at least qualitatively with the theory by Combescot (1975). The imaginary part of the diffusion. coefficient in the B phase was determined from the experimental spin wave frequencies. *Based upon work supported by the National Science Foundation under grants DMR 7901073 and DMR 8403441.