Effect of wall light reflection in ITER diagnostics

The reflection of light from walls will result in parasitic signals for various optical diagnostics and can be a serious issue in ITER. In this study, we show recent progress in the assessment of the effects of wall reflections in ITER based on ray tracing simulation results. Four different diagnostics in ITER were chosen for the simulation, i.e. visible spectroscopy, infrared thermography, edge laser Thomson scattering, and charge exchange recombination spectroscopy.