Propagation of zero sound in liquid He3

The propagation of sound in liquid He3 was observed at a pressure of 0.32 atm and at fre~quencies of 15.4 and 45.5 MHz down to a temperao 0 -3 0 . ture T* of 2m K (1m K = 10 K) on the temperature scale va11d for the Curie-law magnetic susceptibility of powdered cerium magnesium nitrate in the form of a right circular cylinder with diameter equal to height. The results of the measurements have been published by the author, A. C. Anderson, and J. C. Wheatley. * As the temperature was increased, the sound attenuation increased, went through a max.imum, and then decreased. At low temperatures, the attenuation was proportional to T~,(2 but independent of frequency, and at higher temperatures it was proportional to W 2/T*2, where w is the angular frequency of the sound. The temperature at which max.imum attenuation occurred was o 0 11.3m K for the frequency of 15.4 MHz and was 19.3m K for 45.5 MHz. The velocity of the sound was found to be relatively temperature independent at high and low temperatures but near the attenuation maximum the velocity changed by 3.5 ± 0.3 percent. The results of the measurements are predicted by the Landau theory of a Fermi liquid, the velocity change and the temperature dependence of the attenuation coefficient at low temperatures being explained by the propagation of a new mode of sound, called zero sound. The velocity change is in quantitative agreement with the theory. The attenuation of zero sound is about 35% larger than that predicted by theory, but could be explained by a shorter collision time between quasiparticles in the zero sound regime, The frequency and temperature dependence of the attenuation coefficient at higher temperatures are those predicted for ordinary hydrodynamic sound.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2011

Author dc:creator

• Abel, William Russell

Contributors dc:contributor

• Wheatley, J.C.

• sound propagation
• zero sound
• liquid He3
• Curi-law magnetic susceptibility

Statement dc:rights

• 1966 William Russell Abel

Language dc:language

en

Identifier

6178871

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/23983