1. Bidirectional reflectance distribution function of recrystallized tungsten mono-block exposed to cyclic heat loading
- Author
-
Hiroki Natsume, Kunpei Nojiri, Shin Kajita, Makoto Fukuda, Tomohiko Ushiki, Hirohiko Tanaka, Tatsuo Sugie, Sin-iti Kitazawa, Takanori Kikuchi, Tomohiro Yokozuka, Noriyasu Ohno, Koichiro Ezato, and Takaki Hatae
- Subjects
BRDF ,Goniophotometer ,Reflection modeling ,Tungsten monoblock ,Spectroscopic diagnostics ,Recrystallization ,Nuclear engineering. Atomic power ,TK9001-9401 - Abstract
The bidirectional reflectance distribution function (BRDF) of recrystallized tungsten mono-blocks exposed to cyclic heat loading for ITER divertor outer vertical target was measured using a goniophotometer at a wavelength of 473 nm. Laser microscope observations revealed that the surface roughness of the mono-block increased by an order of magnitude after cyclic heat loads of approximately 20 MWm−2. Furthermore, the overall values of BRDF decreased with an increase in cyclic heat loading. A comparison between the modeled and measured BRDFs showed that an additional Lambertian component is necessary to a specular function (microfacet model or Gaussian function) to fit the measured BRDFs when the surface of the mono-blocks becomes rough.
- Published
- 2022
- Full Text
- View/download PDF