Convectively driven superfluid turbulence in dilute solutions of 3He in superfluid 4He

A dilute solution of 3He in superfluid 4He usually behaves as a single component classical fluid in the context of hydrodynamic convection. However, certain convective states can be excited which do not seem to exist in classical convection. These states are characterized by noisy temperature fluctuations and a pronounced decrease in thermal conductance relative to the classical convecting states. Critical convective flow fields are observed analogous to critical velocities for superfluid turbulence in pipes. The magnitude of the average critical velocities for these two types of superfluid turbulence are in good agreement. Also, a quantitative estimate of energy dissipation due to the interaction of normal fluid and quantized vortex lines appears to account for the large decrease in thermal heat transport for the turbulent states. These states are identified as states of convectively driven superfluid turbulence. 23 refs., 5 figs