Bidirectional reflectance measurement of tungsten samples to assess reflection model in WEST tokamak

This paper presents the measurement of bidirectional reflectance distribution function tungsten (W) samples and resulting reflection models in nuclear fusion device WEST (tokamak). For this, an experimental gonio-spectrophotometer was developed to fully characterize material’s optical thermal-radiative properties metallic with different roughnesses. Ray-tracing photonic simulation then carried out predict photon behavior a environment as measurement. Low emissivity (0.1 at 4 μm) highly specular (fitting Gaussian around direction small width lower than 10°) are found for W samples. These measurements have been used input simulation, synthetic image reproduced features well on upper divertor, detected infrared images.