Go to  Advanced Search

The damping of second sound near the superfluid transition in ⁴He

Show full item record

Files in this item

Files Size Format Description   View
UBC_1981_A1 R63.pdf 4.485Mb Adobe Portable Document Format   View/Open
 
Title: The damping of second sound near the superfluid transition in ⁴He
Author: Robinson, Bradley J.
Degree Doctor of Philosophy - PhD
Program Physics
Copyright Date: 1981
Abstract: The attenuation of second sound near the superfluid transition in ⁴He has been determined by measuring the decay time for free oscillations of plane wave modes in a resonant cavity. The results for both the critical exponent and amplitude of the second sound damping coefficient are consistent with the early predictions of Hohenberg, Siggia and Halperin based on renormalization group theory. However, the damping observed in this work is less than the recent predictions of a non-linear renormalization group analysis by Dohm and Folk. The measurements cover the temperature interval 1.8 x 10⁻⁵ ≲ t ≲ 2.1 x 10⁻², where t = (T[sub λ] - T)/T[sub λ]. Fitting the results to a single power law for t < 10⁻³, the critical exponent governing the temperature dependence is found to be 0.31 ± 0.05. If the results are constrained to obey the theoretical asymptotic temperature dependence with an exponent of 0.288, then the amplitude obtained for the damping is 3.7 ± 0.4 cm² s⁻¹. This corresponds to a value for the universal amplitude ratio, R₂, of 0.11 ± 0.01. For t ≳ 10⁻³ the damping departs from the critical behaviour, and increases to obtain the values previously observed by Hanson and Pellam for t ≳ 10⁻².
URI: http://hdl.handle.net/2429/22963
Series/Report no. UBC Retrospective Theses Digitization Project [http://www.library.ubc.ca/archives/retro_theses/]
Scholarly Level: Graduate

This item appears in the following Collection(s)

Show full item record

All items in cIRcle are protected by copyright, with all rights reserved.

UBC Library
1961 East Mall
Vancouver, B.C.
Canada V6T 1Z1
Tel: 604-822-6375
Fax: 604-822-3893