Profile control of reversed-shear current profile and high performance by combined rf current drive

本次调查的目的如下：1. LHCD组合谱的电流驱动效率和物理理解2. LHCD组合谱的反剪切电流剖面和物理理解3.反剪切剖面随电流扩散时间变化的控制方法的发展4.反剪切剖面与高性能的关系，并在循环时间尺度上保持高性能状态所获得的结果如下：首次发现b方向电流降低了驱动电流。驱动（参考文献1 -3）1.发现LHCD可以触发增强电流驱动模式，其特点是电流驱动效率和等离子体约束同时提高。（参考文献1，2，4，12）2.发现超长放电时，密度控制变得困难，壁面泵浦起着重要作用。这些困难的作用。（参考文献5，10）3.新电流。找到了驱动机制，并提出了可能的机制。（参考文献11）4. L到H转换的概率可以由转换发生后的驻留时间引入。（参考文献6 -9）5.ECH导致离子输运的恶化，并且ECH的电子加热不会导致ECD的转变（参考文献13）6。发现ECH增加电流的积极影响，但总驱动效率降低（参考文献13）

The purposes of this investigation are as follows;1.current drive efficiency and physics understanding by combined spectra of LHCD2.reversed-shear current profile and physics understanding by combined spectra of LHCD3.development of control methods for reversed-shear profile over the current diffusion time4.relation between the reversed shear profile and high performance, and maintenance of the high performance state over the recycling time scaleThe obtained results are as follows;It. is found for the first time that the driven current is reduced by b-directional current. drive. (ref.1-3)1.It. is found that the enhanced current drive mode, which are characterized by both suimultaineous improvement of current drive efficiency and plasma confinement, can be triggered by LHCD.(Ref.1,2,4,12)2.It is found that the density control becomes difficult for the ultra long discharge and the wall pumping plays an important. role for these difficulties.(Ref.5,10)3.New current. drive mechanism is found and possible mechanism is proposed.(Ref.11)4. The probability for the L to H transition can be introduced by the resident time after which the transition occurs.(Ref.6-9)5.ECH causes the deterioration of ion transport and electron heating by ECH does not lead the transition for ECD (ref.13 )6. The positive effect of increase in current by ECH is found, but total drive efficiency is reduced (ref.13)