Numerical feasibility study on signal discrimination in reflective environment of tungsten PFC

Abstract

In the reflective environments of tungsten plasma facing components (PFCs), diagnostics of tokamaks will suffer from signal distortions since the reflectivity of tungsten PFCs are not negligible especially in the infrared (IR) range [1,2]. However, considering that most optical reflective systems are linear, it might be possible to eliminate the reflections if all ray information is provided. So, the possibility depends on the ray information of the system, and it can be derived using ray tracing simulations. For the feasibility study, the own ray tracing program of KFE has to be built since the conventional ray tracing programs have a limitation in providing full ray information. Among diagnostics, temperature measurement of PFCs is an issue for tungsten PFCs since it is a fundamental measurement for machine safety. So, as a feasibility study of signal discriminations, the emitted radiance was examined, and it has shown to be quite successful. This paper shows the possibility of reflection discrimination using ray path information.