- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Theses and Dissertations /
- The damping of second sound near the superfluid transition...
Open Collections
UBC Theses and Dissertations
UBC Theses and Dissertations
The damping of second sound near the superfluid transition in ⁴He Robinson, Bradley J.
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.
Item Metadata
Title |
The damping of second sound near the superfluid transition in ⁴He
|
Creator | |
Publisher |
University of British Columbia
|
Date Issued |
1981
|
Description |
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.
|
Genre | |
Type | |
Language |
eng
|
Date Available |
2010-03-29
|
Provider |
Vancouver : University of British Columbia Library
|
Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
|
DOI |
10.14288/1.0085592
|
URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
|
Campus | |
Scholarly Level |
Graduate
|
Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.