Fundumantal Research for Dynamic Engalic Dovertas

1.长脉冲托卡马克放电中的氢再循环通过施加静态或旋转螺旋磁场，发现与等离子体接触的表面积增加，从而新鲜壁面增强了壁面泵浦.旋转螺旋磁场扰动导致的磁岛形成当托卡马克等离子体与旋转螺旋磁场的相对极向速度较小时，磁场重联导致的撕裂模增长最终导致磁岛的形成。它使平衡磁通量表面变形，使得等离子体电流可以在径向和极向方向上调制。这种调制已经通过扰动径向磁场的放大被检测到。在磁螺旋主共振层处，可以清楚地观察到由于磁岛的发展而引起的等离子体电流的重新分布.当相对极向速度为零时穿透扰动磁场的增强衰减 关于我们 在前面的部分中提到的是大的，并且在谐振层处的电子温度相对高，屏蔽电流在该谐振层处流动，使得已经观察到穿透外部磁扰动的强烈衰减。固定频率的磁扰动产生磁岛形成或螺旋场的衰减，这取决于场旋转的方向。这种衰减不仅被认为是由m/n=6/1处的主谐振引起的，而且还被认为是由环形效应产生的m/n=7/1、8/1的边带模式的一些贡献，这已经被数值模拟研究过了.电子温度分布的时间调制由于岛的形成，磁通表面的变形产生电子温度径向分布的时间调制。磁岛的形成和没有磁岛的影响可能会产生不同的行为，现在已经研究过了。剪切Alfven波的激发及其它现象剪切Alfven共振位于磁共振层附近。本文试图通过观察无局部螺旋绕组的环形截面上扰动磁场的径向分量来探测阿尔芬共振引起的磁场增强。已经观察到接近阿尔芬共振层的一些增强。研究了二维极向截面上的相位信息，以明确阿尔芬共振的贡献。少

1. Hydrogen recycling in long-pulse tokamak dischargeBy applying the static or rotating helical magnetic field, the surface area contacting with the plasma was found to increase so that the fresh wall surface enhances the wall pumping.2. Magnetic island formation due to rotating helical magnetic perturbationWhen the relative poloidal velocity between the tokamak plasma and the rotating helical field is relatively small, the growth of tearing-mode by magnetic reconnection produces finally the formation of magnetic island. It deforms the equilibrium magnetic flux surface so that the plasma current may be modulated in radial and poloidal directions. Such a modulation has been detected through an amplification of perturbed radial magnetic field. The redistribution of plasma current due to magnetic island development has been clearly observed at the main resonance layer of magnetic helicity.3. Enhanced attenuation of penetrating perturbed magnetic fieldWhen the relative poloidal velocity me … More ntioned in the previous section is large and the electron temperature at the resonance layer is relatively high, the screening current flows at this resonance layer so that a strong attenuation of penetrating external magnetic perturbation has been observed. The magnetic perturbation with a fixed frequency produces either a magnetic island formation or an attenuation of helical field, depending on the direction of field rotation. Such an attenuation has been thought not only by a main resonance at m/n=6/1 but also by some contributions from the side-band modes of m/n=7/1, 8/1 generated by the toroidal effect, which has been investigated numerical modelling.4. Temporal modulation of electron temperature profileThe deformation of magnetic flux surface due to island formation generates temporal modulation of the radial profile of electron temperature. The effect with and without magnetic island formation may produces different behaviors, which has been investigated now.5. Excitation of shear Alfven waves and other phenomenaThe shear Alfven resonance is located at very close to the magnetic resonance layer. The magnetic field enhancement due to Alfven resonance has been tried to be detected by observing the radial component of perturbed magnetic field at a toroidal section without local helical winding. There have been observed some enhancement close to the Alfven resonance layer. The phase information on the 2-D poloidal cross-section has been investigated to make clear the contribution of Alfven resonance. Less