Measurement of thickness of film deposited on the plasma-facing wall in the QUEST tokamak by colorimetry

作者：Wang Z^*; Hanada K; Yoshida N; Shimoji T; Miyamoto M; Oya Y; Zushi H; Idei H; Nakamura K; Fujisawa A; Nagashima Y; Hasegawa M; Kawasaki S; Higashijima A; Nakashima H; Nagata T; Kawaguchi A; Fujiwara T; Araki K; Mitarai O; Fukuyama A; Takase Y; Matsumoto K

来源：Review of Scientific Instruments, 2017, 88(9): 093502.

DOI：10.1063/1.5000739

After several experimental campaigns in the Kyushu University Experiment with Steady-state Spherical Tokamak (QUEST), the originally stainless steel plasma-facing wall (PFW)becomes completely covered with a deposited film composed of mixture materials, such as iron, chromium, carbon, and tungsten. In this work, an innovative colorimetry-based method was developed to measure the thickness of the deposited film on the actual QUEST wall. Because the optical constants of the deposited film on the PFW were position-dependent and the extinction coefficient k(1) was about 1.0-2.0, which made the probing light not penetrate through some thick deposited films, the colorimetry method developed can only provide a rough value range of thickness of the metal-containing film deposited on the actual PFW in QUEST. However, the use of colorimetry is of great benefit to large-area inspections and to radioactive materials in future fusion devices that will be strictly prohibited from being taken out of the limited area. Published by AIP Publishing.

• 出版日期2017-9