Dissipative Coefficients of Spin-Polarized Superfluid 3He

The attenuation of second sound (spin-entropy) wave in superfluid A 1 -phase has been measured in magnetic fields up to 11 tesla and to sufficiently high frequency to observe the bulk attenuation proportional to the square of frequency. A comprehensive test on the existing theories of hydrodynamics and dissipative coefficients can be made with the measured attenuation coefficient. The spin diffusion coefficient plays a major role in the attenuation. The observed "excess" attenuation is discussed in terms of the temperature dependent spin diffusion coefficient in the superfluid.