Format

Send to

Choose Destination
See comment in PubMed Commons below
J Chem Phys. 2011 Aug 28;135(8):084313. doi: 10.1063/1.3631342.

Optical method for measuring thermal accommodation coefficients using a whispering-gallery microresonator.

Author information

1
Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078-3072, USA.

Abstract

A novel optical method has been developed for the measurement of thermal accommodation coefficients in the temperature-jump regime. The temperature dependence of the resonant frequency of a fused-silica microresonator's whispering-gallery mode is used to measure the rate at which the microresonator comes into thermal equilibrium with the ambient gas. The thermal relaxation time is related to the thermal conductivity of the gas under some simplifying assumptions and measuring this time as a function of gas pressure determines the thermal accommodation coefficient. Using a low-power tunable diode laser of wavelength around 1570 nm to probe a microsphere's whispering-gallery mode through tapered-fiber coupling, we have measured the accommodation coefficients of air, helium, and nitrogen on fused silica at room temperature. In addition, by applying thin-film coatings to the microsphere's surface, we have demonstrated that accommodation coefficients can be measured for various gases on a wide range of modified surfaces using this method.

PMID:
21895191
DOI:
10.1063/1.3631342
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Institute of Physics
    Loading ...
    Support Center