Thermal behavior and temperature measurements of melting beryllium plasma-facing components exposed to high heat flux

Abstract The emissivity of metallic materials is low and varies with temperature and wavelength inducing errors on surface temperature measurements. High heat flux experiments on beryllium were carried out to investigate the thermal behavior of bulk Be tiles. Thermal modeling aiming at determining the surface and bulk temperatures have been performed using ANSYS®. A Be tile was exposed to heat flux with power density ranging between 1 and 7 MW/m 2 . Surface temperatures were measured using an infrared camera in the 3–5 μm range and two-color pyrometers, one at short wavelengths (1.5–1.7 μm) and one at mid IR range wavelengths (2–4 μm) range. Both the IR camera and two-color pyrometers do not provide accurate temperature measurements on melted Be due to changes in the emissivities and emissivity ratio induced by surface modifications.