Physics of anomalous transport and confinement improvement

理论研究成果有：(1)建立了自持续输运模型(临界湍流特性、谱。(2)螺旋系统约束改进理论和准则(3)坍缩现象理论。(4)非本地运输模式的发展。实验结果包括：(5)螺旋系统约束改善的发现(6)动量输运的研究(7)径向电场分岔。无碰撞电子衰变长度尺度下微湍流的实验证据。在环面等离子体的径向电场结构中，理论上预测了径向电场的分岔面。径向电场分岔面是强正径向电场和负（或弱正）径向电场之间的表面。从理论上预测了在径向电场梯度强的区域异常输运会减少。在螺旋体系中，这种机制预计会产生更多的内部输运屏障。在常规的异常输运模式下，帽通量穿越磁通量用磁通量表面的局部等离子体参数表示。在理论框架中，很难解释W7AS器件中观察到的外部触发的快速响应。通过对W7AS观测数据的分析，提出了新的非局域输运模型。在自持续输运模型中，预测了一种湍流向另一种湍流的转变，并提出了elm和内部输运势垒坍塌等坍缩现象的理论。实验研究有了重大进展。在CHS中，观察到两种不同电位分布之间的转变。这是在环形等离子体中首次观察到的自发电位分岔现象，支持了对径向电场分岔的催眠。两个剖面之间的转变是连续的，并对稳态螺旋等离子体产生影响。在托卡马克等离子体和螺旋等离子体中预测了这些分岔，在动量输运中理论上预测了等离子体压力引起的等离子体流动。在此基础上进行了详细的实验，研究了流速梯度与动量通量的关系。结果表明，动量输运中存在的动量通量不是由流动梯度引起的，而是由离子压力梯度或离子温度梯度引起的。少

Theoretical research results are (1) Development of self sustained transport model (critical turbulence characteristics, spectral. turbulence), (2) Theory of confinement improvement and guideline for helical system (3) Theory of collapse phenomena.(4)Development of non local transport model. Experimental results are (5) Finding of confinement improvement in Helical system (6) Research of momentum transport (7) Bifurcation of radial electric field. Experimental evidence of micro turbulence in the scale of collisionless electron decay length.The bifurcation surface of radial electric field is predicted theoretically in the structure of radial electric field in torus plasma. The radial electric field bifurcation surface is the surface between the strong positive radial electric field and negative (orweak positive) radial electric field. It is theoretically predicted that the anomalous transport is reduced in the region where the gradient of radial electric field is strong. Theoretically i … More nternal transport barrier is predicted to be produced by this mechanism in helical system.In the conventional anomalous transport mode, the hat flux crossing the magnetic flux is expressed with local plasma parameter at the magnetic flux surface. In the theoretical frame work, it is difficult to explain the fast response for external trigger observed in W7AS device.New non-local transport model is proposed by analyzing the observation in W7AS.The heat flux across the magnetic flux surface is affected by the radial profile of plasma because of the turbulence of long wavelength comparable to the plasma size, In the self sustained transport model, the transition of one turbulence to the other is predicted and theory of collapse phenomena such as ELMs and internal transport barrier collapse is proposed.There is significant development of experiment research. In CHS the transition between the two different profiles of electric potential was observed. This is the first observation for spontaneous electric potential bifurcation in toroidal plasma and supports the hypnosis of bifurcation of radial electric field. The transition between two profiles are continuous and give the impact to steady state helical plasma.These bifurcation is predicted in tokamak plasma as well as helical plasma and plasma flow due to the plasma pressure is theoretically predicted in the momentum transport. The detail experiments on this issue has been done and the relation between the gradient of flow velocity and momentum flux is studied. It is clearly demonstrated that the momentum flux not due to the gradient of flow but the gradient of ion pressure or ion temperature exists in the momentum transport. Less