Quasiparticle Damping of Surface Waves in Superfluid ³He and ⁴He

الأصل · EN

Oscillations on free surface of superfluids at the inviscid limit are damped by quasiparticle scattering. We have studied this effect in both superfluids ³He and ⁴He deep below the respective critical temperatures. Surface oscillators offer several benefits over immersed mechanical oscillators traditionally used for similar purposes. Damping is modeled as specular scattering of ballistic quasiparticles from the moving free surface. The model is in reasonable agreement with our measurements for superfluid ⁴He but significant deviation is found for ³He.