Measurement of the velocity and attenuation of fourth sound in helium II

Journal Article · Sun Jul 01 04:00:00 EDT 1979 · J. Low Temp. Phys.; (United States)

DOI:https://doi.org/10.1007/BF00174917· OSTI ID:6048720

Lauter, H; Wiechert, H

The velocity and the attenuation of fourth found have been measured in liquid helium at temperatures between 0.8 K and the lambda point, along the vapor pressure curve. The measurements were made using the resonance technique and the helium was contained between small pores in packed powder specimens. From the velocity, it could be determined that the sound propagates under ''adiabatic'' conditions. According to theory, the attenuation of fourth sound consists of two contributions: surface losses due to heat exchange with the resonator body and volume losses due to dissipative processes associated with the viscosity coefficients eta and zeta/sub 3/. The results of our attenuation measurements are in agreement with this theory; however, it appears that the attenuation is affected at low temperatures, if the mean free path of an elementary excitation becomes comparable to or larger than the mean pore diameter of the packed powder samples.

• Research Organization: Institut fuer Physik, Johannes Gutenberg Universitaet, Mainz, West Germany
• OSTI ID: 6048720
• Journal Information: J. Low Temp. Phys.; (United States), Journal Name: J. Low Temp. Phys.; (United States) Vol. 36:1; ISSN JLTPA
• Country of Publication: United States
• Language: English

Related Subjects

640450* -- Fluid Physics-- Superfluidity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATTENUATION
EVEN-EVEN NUCLEI
FLUIDS
FOURTH SOUND
HELIUM 4
HELIUM II
HELIUM ISOTOPES
ISOTOPES
LIGHT NUCLEI
MEAN FREE PATH
NUCLEI
QUANTUM FLUIDS
STABLE ISOTOPES
VELOCITY