PLASMA TRANSPORT STUDY BY ANLYSIS FOR TRANSIENT RESPONSES TO APPLIED

这项研究的目的是通过分析局部非均匀扰动的瞬时响应来解决等离子体输运问题。主要研究结果如下：(1)1997年研究了氦加速器E的内部分裂和ECRH降低快离子损失的问题。得到了内部破裂过程中扰动幅度与压力梯度之间的滞后关系。这种观察需要对这一过程作出新的解释，而这不是线性理论所能描述的。虽然ECRH加热电子并产生高能电子，但势能分布也可以改变。当等离子体电势变得更正时，共振快离子损耗有望降低。在1998年用LHCD等离子体进行的TRIQM-1M离子加热实验中，研究了电子速度分布函数的扭曲对离子加热过程的影响。研究发现，低频波被扭曲的电子分布激发，并将其能量传递给具有垂直速度分量的离子。(3)1999年研究了双向低杂波与载流电子之间的耦合。结果表明，同向运动电子的电流驱动效率与双向波的功率比呈非线性关系。随着CTR行波功率的增大，电流分布由峰值突变为平坦。

The purpose of this research is to resolve the plasma transport by analysing transient responses to local non-uniform perturbations. The following results are obtained.(1)In Heliotron E internal disruption and reduction of the fast ion loss by ECRH are investigated in 1997. The hysteresis relation between the amplitude of the perturbation and the pressure gradient is obtained during the internal disruption process. This observation requires a new explanation for this process, which cannot be described by the linear theory. Although ECRH heats the elctrons and creates energetic electrons, the potential profile can be also changed. When the plasma potential becomes more positive, the reduction of the resonant fast ion loss is expected. This process is experimentally confirmed.(2)In TRIQM-1M ion heating have been studied in LHCD plasmas in 1998 The effect of the distortion of the electron velocity distribution function is studied on the ion heating process. It is found that low frequency waves are excited by distorted electron distribution and transfer their energy to ions with perpendicular velocity component.(3)The coupling between bi-directional lower hybrid waves and current carrying electrons are investigated in 1999. It is found that the current drive efficiency for the co-moving electrons shows a non linear response for the power ratio of the bi-directional waves. The abrupt current profile change from a peaked one to a flat one is observed as the ctr-travelling wave power is increased.