The Construction Of The High Speed CCD Imaging System And Its Application On The J-TEXT Tokamak

The high speed CCD imaging system is widely used in the research of magnetic confinement fusion,not only for the displacement monitoring of plasma,but also for the visible light radiation measurement and the study of physical phenomena such as turbulence.Therefore,it is necessary to develop a high speed CCD imaging system on the J-TEXT tokamak device.Based on the J-TEXT Tokamak,a high speed CCD imaging system is established as an auxiliary diagnostic system for the plasma displacement monitoring.The system takes the 3CXP high-speed camera of the Germany MIKROTRON company and NTCAM132 X image acquisition card of the Israel KYYA company as the core hardware and is equipped with a high-resolusion wide-angle zoom optical system.A program for controlling it is also developed based on the Microsoft Visual Studio 2012 development platform.Then,the following research have completed based on the high speed CCD imaging system:First is the calibration of the high speed CCD imaging system.some characteristic contours of the standard flange windows in the vacuum chamber are choosed as the calibration points in space coordinate system.At the same time,using the Canny algorithm to detect the characteristic contours in images to get its accurate coordinates in pixel coordinate system.Then a Tsai two-step calibration algorithm is utilized to build the relationship between the spatial coordinate system and the pixel coordinate system.By analysing and verifying the calibration results,the feasibility and accuracy for the calibration algorithm are proved.Second is the reconstruction of the 2-D poloidal emission profiles based on the high speed CCD imaging system.Based on the assumption of the toroidal symmetry about visible light radiation and the results of the imaging system's calibration,a 2-D poloidal emission profile is obtained by using tangential tomography reconstruction algorithm.In the J-TEXT tokamk experiments,the CIII poloidal emission profiles have reconstructed by adding CIII filter in front of the camera,which verifies the feasibility of the reconstruction algorithm.The tangential tomography reconstruction algorithm used in the imaging system provides a new way to measure the visible light radiation.