3D surface morphology measurement using improved laser speckle interferometry in presence of white light background

摘要

The morphology monitoring of the wall surface of the Tokamak is of significance for understanding the erosion and deposition phenomena that occur on the wall surface. Laser speckle interferometry (LSI) is a technique that can measure the three-dimensional morphology of surfaces on-line in-situ, which can achieve real-time non-destructive measurement. In this paper, the influence of continuous white light emitted by plasma discharge on the LSI measurement is investigated off-line. The experimental results show that the existence of white light background is not conducive to the measurement of three-dimensional morphology of the plasma-facing-components (PFCs) by LSI in Tokamak. Therefore, we propose an improved laser speckle interference (ILSI) technology based on frequency domain and spatial domain filters to depress white light background. The experimental results show that the ILSI works well. This lays a theoretical foundation for the future application of LSI technology to Tokamak devices.