Techniques Used for Registration and Reconditioning of Infrared Images of the Experimental Advanced Superconducting Tokamak (EAST) Divertor

摘要

The heat flux loaded on the divertor is an important issue in tokamaks. At present, the heat flux on the divertor is calculated from the divertor surface temperature measured by the infrared (IR) camera. However, the movement of the field of view and the geometrical distortion are present in the IR images. Small movements occur with machine shaking during normal discharges, while large ones often arise at disruptions or the rapid variations in the magnetic field. As a result, it is difficult to obtain the real temperature evolution on the specified divertor surface from the IR images. In this paper, the scale invariant feature transform descriptors andK-means clustering have been applied for vibration correction on the IR videos in EAST. The projective transformation is used to correct the geometrical distortion in the IR images. The experimental results show that the proposed methods are efficient in compensating for image translations brought about by vibrations and for perspective distortions in the images, thereby allowing assignment of the IR emission-derived surface temperatures to the correct locations on the divertor surface.