Study On The Characteristics Of Tokamak Plasma Based On Visible/Infrared Camera System

The first wall materials of Tokamak devices have a direct effect on achieving higher power and longer duration steady-state plasma operation.In order to assure the safety of steady-state operation of fully superconducting Tokamak,EAST(Experimental Advanced Superconducting Tokamak),a wide-angle visible /infrared camera endoscope diagnostic system has been developed to monitor the temperature distribution of inner components,like lower/upper diverter,high field side wall,limiter and so on.Based on the developed visible/infrared camera endoscope diagnostic system,this thesis gives some research results including plasma shape identification and diverter target heat fluxes during EAST discharge.The main content of this thesis is shown as follows:1.Design of visible/infrared camera endoscope diagnostic system.According to the structure feature and monitor-window location of EAST device,this thesis introduces the optical design of integrated visible/infrared camera endoscope diagnostic system.Based on EAST experiment requirement,the image acquisition and processing software based on visible camera V710 and the software for infrared thermography SC7700 BB are written by using the MFC design module of VS2008 respectively.On the basis of both visible and infrared cameras’ experiment data during discharges,the system achieve mostly the real time functions,like recording,storing,replaying and processing.The diagnostic system are successfully implemented for EAST discharges.2.Plasma boundary detection based on visible camera during EAST discharges.Firstly,distortion removal and distance calibration are achieved by calibrating the visible camera and the whole endoscope system.Then the last closed flux surface of plasma during discharges has been obtained through the improved Canny operator to detect plasma boundary by visible images,which can be used for further plasma shape control.Effectiveness of the algorithm used in this thesis has also been validated by comparing to plasma shape reconstructed from EFIT(Equilibrium FITing algorithm).3.Study on divertor heat flux calculation and its related characteristics.This thesis introduces the algorithm design for heat flux computation in detail.The heat flux on divertor targets could be calculated by using the temperature on EAST diverter target plates obtained from infrared thermography and the strike point position could be obtained by using calculated peak heat flux,and conducts relative physical analysis on divertor heat flux.Visible/infrared camera system is the most intuitive diagnostic approach among EAST diagnostic systems.This thesis gives preliminary study on visible/infrared cameras and achieves some results.Some other work,just like visible/infrared image fusion,etc.would be done for the further research with the ambition on more physical results.