Thermal wave characterization of plasma-facing materials by IR radiometry

An experiment based on the IR detection of thermal waves has been developed, which allows the measurement of periodic temperature oscillations of 3–7 mK at average sample temperatures of 450–1000 K. Measurements have been performed on various plasma-facing materials. The thermal diffusivity, effusivity and thermal depth profiles of graphite have been determined at different temperatures, thus demonstrating the potentiality of this method for remote in situ measurements of thermal properties and nondestructive evaluation of plasma surface modifications in nonaccessible hostile environments.