Influence of reflected light from the chamber inner wall upon electron temperature and density in plasma diagnostics by tomographic optical emission spectroscopic measurement
In tomographic optical emission spectroscopic measurement of plasmas, multiple reflections on the chamber inner wall can increase the measurement uncertainty. In this study, we experimentally investigated the influence of reflectance of the chamber inner wall and the layout of line-of-sights on the reconstructed image. The use of a pressurized, vapor-sealed, anodized aluminum inner wall in the chamber reduced the distortion of the reconstructed image. Based on the collisional radiation model, the spatial distribution of electron temperature and electron density were diagnosed.