Fundumantal Research for Dynamic Engalic Dovertas

1.长脉冲托卡马克放电中的氢气回收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，从而使新鲜的壁表面增强了壁泵浦。2．旋转螺旋磁扰动形成磁岛当托卡马克等离子体与旋转螺旋场之间的相对极向速度较小时，磁重联撕裂模式的增长最终导致磁岛的形成。它使平衡磁通量表面变形，从而可以在径向和极向方向上调制等离子体电流。这种调制是通过扰动径向磁场的放大来检测的。在磁螺旋的主共振层上可以清楚地观察到由于磁岛的形成而引起的等离子体电流的重新分布。3．穿透性扰动磁场的衰减增强当上节提到的相对极向速度较大且谐振层的电子温度较高时，该谐振层处会流过屏蔽电流，从而观察到穿透性外磁扰动的强烈衰减。具有固定频率的磁扰动会产生磁岛形成或螺旋场衰减，具体取决于场旋转方向。人们认为这种衰减不仅是由 m/n=6/1 处的主谐振引起的，而且还受到环形效应产生的 m/n=7/1、8/1 边带模式的一些贡献，这已通过数值模拟进行了研究。4．电子温度分布的时间调制由于岛的形成而导致的磁通量表面的变形产生电子温度的径向分布的时间调制。有和没有磁岛形成的效应可能会产生不同的行为，目前已对此进行了研究。 5．剪切阿尔文波的激发和其他现象剪切阿尔文共振位于非常靠近磁共振层的位置。已经尝试通过观察没有局部螺旋缠绕的环形截面处的扰动磁场的径向分量来检测由于阿尔文共振而产生的磁场增强。已经观察到靠近阿尔文共振层的一些增强。研究了二维极向截面上的相位信息，以明确阿尔文共振的贡献。较少的

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