Laser flash measurement of the phononic thermal diffusivity of glasses in the presence of ballistic radiative transfer
Jürgen Blumm, Jack B Henderson, Ove Nilsson, Jochen Fricke
A new technique has been developed for measuring the phononic thermal diffusivity of glasses by the laser flash method at temperatures between 300 and 1000 K. The usual calculation procedures for laser flash devices are based on the Fourier differential equation, which takes into consideration only diffusion processes. In glasses, additional radiative heat transfer appears at high temperatures, causing a change in the characteristic form of the temperature – time curve. Therefore, the evaluation of the experimental data must be modified.