Phonon-quasiparticle interactions in dilute solutions of He3 in superfluid He4

Both the nature of phonon-quasiparticle interactions in dilute solutions of He3 in superfluid He4 and the role they play in determining the linear response prQperties of such solutions are examined. The vertices for phonon scattering and absorption by He3 quasiparticles as well as the effective interaction between quasiparticles are discussed from the microscopic theory. Much of the previous semiphenomonological theory concerning these quantities is justified. The properties of a dilute gas model for dilute solutions are worked out to first order in the gas parameter; the results provide an example and a check for the general theory. Using the phonon-quasiparticle vertices a phonon Boltzmann equation is developed. This equation is completely soluble in the absence of protons and phonon-phonon interactions, and it is used in conjunction with the quasiparticle Boltzmann equation and the superfluid equation of motion to determine the attenuation' of both first and second sound and the kinetic coefficients in dilute solutions. There is good overall agreement with available experimental results for first sound attenuation.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Year dc:date

2011

Author dc:creator

• Saam, William Frederick

Contributors dc:contributor

• Baym, Gordon A.

• phonon-quasiparticle interactions
• superfluid He
• linear response properties
• phonon scattering

Statement dc:rights

• 1968 William Frederick Saam

Language dc:language

en

Identifier

6076052

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/25752