Third sound in /sup 4/He adsorbed on Nuclepore

Journal Article · Mon Apr 08 00:00:00 EST 1985 · Phys. Rev. Lett.; (United States)

DOI:https://doi.org/10.1103/PhysRevLett.54.1528· OSTI ID:6024837

Valles, Jr, J M; Smith, D T; Hallock, R B

Measurements of the velocity of third sound C/sub 3/ in /sup 4/He films adsorbed on Nuclepore filter material with and without pores have been made and reveal striking structure as a function of film thickness for the porous case. In the absence of capillary condensation the data are understood in terms of a model which predicts the porous index of refraction as a function of coverage. It is likely that the techniques employed will be a useful alternative to the Brunauer-Emmett-Teller method for the determination of surface areas. For helium film coverages above those necessary for capillary condensation a fast propagating mode with speed vapprox.C/sub 3//sup 1/2/ is observed.

• Research Organization: Laboratory for Low Temperature Physics, Department of Physics and Astronomy, University of Massachusetts, Amherst, Massachusetts 01003
• OSTI ID: 6024837
• Journal Information: Phys. Rev. Lett.; (United States), Vol. 54:14
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ADSORPTION
THIRD SOUND
HELIUM 4
EXPERIMENTAL DATA
POROUS MATERIALS
THICKNESS
VAPOR CONDENSATION
VELOCITY
DATA
DIMENSIONS
EVEN-EVEN NUCLEI
HELIUM ISOTOPES
INFORMATION
ISOTOPES
LIGHT NUCLEI
MATERIALS
NUCLEI
NUMERICAL DATA
SORPTION
STABLE ISOTOPES
640450* - Fluid Physics- Superfluidity