Ultrasound velocity under the turbulence in superfluid⁴He

Abstract

High frequency ultrasound velocity and attenuation were measured under the turbulence or tangled vortices, which were introduced by the electron drift current. The measurement was done at 0.3 K for the pressure range of 12–24 bar. The result implies the possibility that the vortex is created by the sound itself, resulting in the increase of the velocity.