title: Dissipation mechanisms near the superfluid 3He transition in aerogel.
abstract: We have investigated the dissipation (Q-1) using the torsion pendulum technique for pure 3He and 3He-4He mixtures in silica aerogel near the 3He superfluid transition (T(c)) in aerogel. With pure 3He the Q-1 decreases at the onset of superfluidity. When phase separated 3He-4He mixtures are introduced into the aerogel, the Q-1 does not decrease as rapidly and eventually increases for the highest 4He content. We provide a model for the related attenuation of transverse sound alpha that takes into account elastic and inelastic scattering processes and exhibits a decrease in alpha at T(c).
authors.affiliation: Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York 14853, USA.
authors.forename: A I
authors.initials: AI
authors.lastname: Golov
authors.forename: D
authors.initials: D
authors.lastname: Einzel
authors.forename: G
authors.initials: G
authors.lastname: Lawes
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
authors.forename: J M
authors.initials: JM
authors.lastname: Parpia