Fundumantal Research for Dynamic Engalic Dovertas

1.长脉冲托卡马克放电中的氢循环通过施加静态或旋转的螺旋磁场，发现与等离子体接触的表面积增加，从而使新鲜的壁面增强了壁面泵浦。旋转螺旋磁扰动形成磁岛当托卡马克等离子体和旋转螺旋场之间的相对极向速度较小时，磁重联导致撕裂模的增长最终形成磁岛。它使平衡磁通面变形，从而使等离子体电流可以在径向和极向进行调制。这种调制已经通过扰动径向磁场的放大而被检测到。在磁旋度的主共振层观察到了磁岛发展引起的等离子体电流的重新分布。相对极向速度Me…时穿透扰动磁场的增强衰减在前一节中较大且共振层电子温度较高的情况下，屏蔽电流流经该共振层，从而观察到穿透外部磁扰动的强烈衰减。具有固定频率的磁扰动要么产生磁岛形成，要么产生螺旋场的衰减，取决于场旋转的方向。这种衰减不仅是由m/n=6/1处的主共振引起的，而且还与由环形效应产生的m/n=7/1、8/1的边带模式的某些贡献有关，这一点已被数值模拟研究。电子温度分布的时间调制由于岛的形成，磁通量表面的变形产生了电子温度径向分布的时间调制。有和没有磁岛形成的影响可能会产生不同的行为，这一点现在已经被研究过了。剪切Alfven波的激发和其他现象剪切Alfven共振位于非常接近磁共振层的位置。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Alfven共振引起的磁场增强。在Alfven共振层附近观察到了一些增强。研究了二维极向截面上的位相信息，以明确Alfven共振的贡献。较少

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