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Measurement of thermal diffusivity at high pressures and temperatures using synchrotron radiography

Published online by Cambridge University Press:  05 July 2018

D. P. Dobson*
Affiliation:
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK
S. A. Hunt
Affiliation:
Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK
L. Li
Affiliation:
Department of Geosciences, Mineral Physics Institute, State University of New York at Stony Brook, Stony Brook, NY, 11794-2100, USA
D. Weidner
Affiliation:
Department of Geosciences, Mineral Physics Institute, State University of New York at Stony Brook, Stony Brook, NY, 11794-2100, USA
*

Abstract

A new method to measure thermal diffusivity in samples at simultaneous high pressure and high temperature is presented. The sample is placed inside a cylindrical heater and subjected to a heater power that varies sinusoidally with time. The diffusion of the temperature variations into the sample is monitored using radiographic imaging of marker foils. This provides measurements of the phase lag and amplitude variation of the temperature cycle at a range of radii from the sample axis without the need for multiple thermocouples. The technique is tested using a NaCl sample at 4 GPa; the best-fit thermal diffusivity for NaCl at 4 GPa and 673 K is 2.4±0.5x10-6 m2/s.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2008

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References

Brualla, L. and Martin, P. (2001) Analytic approximations to Kelvin functions with applications to electromagnetics. Journal of Physics A: Mathematical and General, 34, 91539162.CrossRefGoogle Scholar
Katsura, T. (1993) Thermal diffusivity of silica glass at pressures up to 9 GPa. Physics and Chemistry of Minerals, 20, 201208 CrossRefGoogle Scholar
Khedari, J. Benigni, P., Rogez, J. and Mathieu, J.C. (1995) New apparatus for thermal diffusivity measurements of refractory solid materials by the periodic stationary method. Reviews of Scientific Instruments, 66, 193198 CrossRefGoogle Scholar
Li, L., Raterron, P., Weidner, D. and Chen, J. (2003) Olivine flow mechanisms at 8 GPa. Physics of the Earth and Planetary Interiors, 138, 113129.CrossRefGoogle Scholar
Nimmo, F., Price, G.D., Brodholt, J. and Gubbins, D. (2004) The influence of potassium on core and geodynamo evolution. Geophysical Journal International, 156, 363376.CrossRefGoogle Scholar
Sato-Sorensen, Y. (1983) Phase transitions and equations of state for the sodium halides: NaF, NaCl, NaBr and Nal. Journal of Geophysical Research, 88, 35433548.CrossRefGoogle Scholar
Temple, P.A. (1975) An introduction to phase-sensitive amplifiers: an inexpensive student instrument. American Journal of Physics, 43, 801807.CrossRefGoogle Scholar
Xu, Y., Shankland, T.J., Linhardt, S., Rubie, D.C., Langenhorst, F. and Klasinski, K. (2004) Thermal diffusivity and conductivity of olivine, wadsleyite and ringwoodite to 20 GPa and 1373 K. Physics of the Earth and Planetary Interiors, 143—144, 321336.CrossRefGoogle Scholar