SPIN-ENTROPY WAVE-PROPAGATION IN HE-3 A(1) IN MAGNETIC-FIELDS UP TO 12 TESLA

The propagation of spin-entropy wave has been studied in He-3 Al in ma gnetic fields up to 12 tesla and at a pressure of 22.9 bar. The superf luid fraction at T-c2 extracted from the propagation velocity increase s linearly with magnetic field and reduced temperature. The anomalous attenuation previously found near T-c2 in lower magnetic fields was al so observed in the present maximum field. The pore size in the oscilla ting superleak transducer does not affect the anomalous attenuation. O utside the anomalous attenuation region, the dissipation coefficient i s found to vary linearly with frequency. This frequency dependence is contrary to that of dissipations owing to viscous losses at walls and to bulk losses.