撕裂模实时主动控制系统

Tearing mode real time active control system

在HL-2A装置上发展了一套撕裂模实时主动控制系统。该系统在放电期间用电子回旋发射/软X射线诊断实时确定撕裂模的几何位置,结合实时剖面重建和电子回旋波沉积计算,得到电子回旋波反射镜的控制角度值。通过电机实时驱动电子回旋波反射镜到达指定角度,使得电子回旋波功率沉积在撕裂模的有理磁面附近,改变当地局部的电流剖面,从而控制撕裂模,改善等离子体约束。该系统已经在2015年以后的实验中投入使用,并取得了良好的控制效果。它不仅能够实时发现并控制经典撕裂模,并且具有控制新经典撕裂模的潜力。

Tearing mode real-time active control system has been developed on HL-2A tokamak.During the plasma discharge,electron cyclotron emission and soft X-ray diagnostic signals are used to get the geometric location where tearing modes emerge,combined with the real time profile reconstruction and electron cyclotron wave (ECW)deposition algorithm,the target angle of ECW steering mirror can be obtained.Then the mirror angle is set by the motor so that the ECW power deposit at the position of tearing modes finally.Consequently the tearing modes can be controlled,owing to the change of local current profile,and the plasma confinement is improved.This system has been deployed in HL-2A campaigns after 2015,and the good control effect is obtained. It has been proved that the system can discover and control not only the classical tearing modes in real time,but also has the potential to control the neoclassical tearing mode in the future.