Modelling the damping force exerted on a macroscopic object moving through superfluid3He-B in the ballistic regime

✍ Scribed by M.P. Enrico; S.N. Fisher; R.J. Watts-Tobin

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 154 KB
• Volume: 194-196
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(94)90723-4

✦ Synopsis

We present a microscopic theory of the thermal damping force on a macroscopic object moving through the B-phase of superfluid 3He in the ballistic regime. The force arises from an imbalance between the quasiparticle and quasihole contributions to the momentum transfer resulting from Andreev reflection by the superflow round the object. In a previous simple approach the object was assumed to be smooth, giving rise to specular scattering of incident excitations. We have based the present model on the more realistic diffuse scattering of excitations in an effort to take into account the microscopic roughness of the object. The theory gives excellent agreement with experimental measurements of the damping force on a vibrating wire resonator throughout the velocity range.