Abstract
An experimental method is described for the determination of the thermal diffusivity by the measurement of the phase difference between the temperature fluctuations at two faces of a thin plate of material, where the applied heat by an electron gun is modulated sinusoidally. An approximate equation of the relation between phase difference and thermal diffusivity of ceramics has been obtained so that thermal diffusivity of ceramics can be measured at high temperature without direct measurements of heat loss parameters. The results for the thermal diffusivity and the thermal conductivity of MgO and UO2from 900°C up to 1,700°C were obtained by this method and apparatus with the estimated accuracy of ±10%. The measured thermal conductivities of MgO and UO2are in good agreement with the standard values.