Acoustic properties of superleaks partially saturated with superfluid

Conference · Sun Jan 01 04:00:00 EST 1984 · AIP Conf. Proc.; (United States)

OSTI ID:5053526

Baker, S; Marcus, J; Williams, G A; Rudnick, I

The index of refraction, n, has been measured for the sound mode which propagates in a superleak partially filled with liquid He II so that the liquid forms a film on the powder grains. Motivated by a model which treats the scattering from the powder grains independently from the scattering from the vapor spaces, the authors find that for filling fractions f > 0.4 the data ware well described by n/sup 2/ = p/sup -..beta../sub 1//f/sup -..beta../sub 2// with ..beta../sub 1/ = 0.67 and ..beta../sub 2/ = 1.29 and where f is the fraction of the pore volume occupied with liquid He II and P is the fraction of the volume occupied by both liquid and vapor He. Unusual behavior is observed for low filling fractions. Below f = 0.4 n rises with decreasing f to a peak value of nearly 10 before dropping precipitiously to a constant value of 3.7 in the limit of very thin films.

• Research Organization: Univ. of California, Los Angeles
• OSTI ID: 5053526
• Report Number(s): CONF-8310216-
• Conference Information: Journal Name: AIP Conf. Proc.; (United States) Journal Volume: 107
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
640450 -- Fluid Physics-- Superfluidity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACOUSTIC MEASUREMENTS
EVEN-EVEN NUCLEI
FILMS
FLUIDS
GASES
HELIUM 4
HELIUM II
HELIUM ISOTOPES
ISOTOPES
LIGHT NUCLEI
LIQUIDS
MATERIALS
NUCLEI
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
POROSITY
POROUS MATERIALS
QUANTUM FLUIDS
REFRACTIVITY
SCATTERING
SECOND SOUND
STABLE ISOTOPES
THIRD SOUND
VAPORS
WAVE PROPAGATION