Optimization of Helical Plasma Confinement

作为螺旋等离子体优化方法之一，在常规螺旋系统中研究了P-S电流的抑制。P-S电流引起磁表面的变形，从而导致能量约束的恶化。对于1=2的无剪切仿星器和1=3的Heliotron/Heliotron，垂直场引起的强磁轴内移对抑制P-S电流是有效的在轴向无旋转变换的扭转管中，除了通过控制偶极场来向内移动外，还需要通过控制四极场来垂直拉长磁面。本文提出了一种基于二维螺旋系统的仿星器优化方案，该方案比W7-X方案更具有一般性，但在磁轴附近受到限制。在2-D配置中，粒子约束与常规配置相比得到了显着改善。 ...更多信息 本文介绍了一种新的螺旋系统--准环形对称仿星器，它是一种三维螺旋系统。这种思想有助于促进准环形对称仿星器的发展，它被认为是一种新的优化螺旋系统。重离子束探针在CHS中首次成功地用于螺旋机器中测量等离子体的静电势。这里，在重离子束流入口和出口均采用八极偏转器控制束流轨迹，并与俄罗斯的控制方法进行了比较，提出了一些看法。本文对ICRF在CHS中的电子加热与L-2的结果进行了比较。在CHS高场侧反射中，R切-R关是新引进的。ICRF波物理学在真实的机器中的进展，以解释实验结果。仿星器的未来合作最优化、优化配置中的输运代码、抗磁测量、ECH等离子体中的电子分布函数、模块化线圈设计等。少

Suppression of Pfirsch-Schluter (P-S) current has been investigated in a conventional helical system as one of helical-plasma-optimization procedures.P-S current causes a deformation of magnetic surfaces which results in the deterioration of the energy confinement.Strong inward shift of magnetic axis shift by a vertical field is effective to suppress the P-S current for an 1=2 stellarator with no shear and for an 1=3 heliotron/torsatron with no rotational transform at axis.For an 1=2 heliotron/torsatron with shear and central rotational transform, it is necessary to elongate the magnetic surface vertically by controlling the quadrupole field in addition to the inward shift by controlling the dipole field.New scenario of stellarator optimization, which was based on the 2-dimensional helical system, was shown.This is more general than the W7-X strategy, but is limited near the magnetic axis.In the 2-D configuration, the particle confinement is dramatically improved compared with a conven … More tional helical system which is of 3-D geometry.This idea helps to promote the quasi-toroidal symmetric stellarator which is now being considered as a new optimized helical system.Heavy ion beam probe is successfully operated in CHS,for the first time in helical machines, to measure the electrostatic potential of the plasma.Here, heavy ion beam trajectory is controlled by octopole deflectors both at the inlet and outlet of the beam.The control method of beam trajectory was compared with that of the russian type and there were some comments from russian side to improve our system.Some of them are for reducing UV light effect which causes emission of secondary electrons resulting in the operation limit on the electron density.Electron heating of ICRF in CHS was compared with L-2 results.In CHS reflection at the high field side R cut-off is newly introduced.ICRF wave physics in real machines is in progress to explain experimental results.Future collaboration on stellarator optimization, transport code in the optimized configuration, diamagnetic measurement, electron distribution function in ECH plasma, modular coil design, has been discussed. Less