Active feedback stabilization of multiple resistive wall modes (RWMs) has been successfully proven in the EXTRAP T2R reversed field pinch. One of the features of plasma discharges operated with active feedback stabilization, in addition to the prolongation of the plasma discharge, is the sustainment of the plasma rotation. Sustained rotation is observed both for the internally resonant tearing modes (TMs) and the intrinsic impurity oxygen ions. Good quantitative agreement between the toroidal rotation velocities of both is found: the toroidal rotation is characterized by an acceleration phase followed, after one wall time, by a deceleration phase that is slower than in standard discharges. The TMs and the impurity ions rotate in the same poloidal direction with also similar velocities. Poloidal and toroidal velocities have comparable amplitudes and a simple model of their radial profile reproduces the main features of the helical angular phase velocity. RWMs feedback does not qualitatively change the TMs behaviour and typical phenomena such as the dynamo and the 'slinky' are still observed. The improved sustainment of the plasma and TMs rotation occurs also when feedback only acts on internally non-resonant RWMs. This may be due to an indirect positive effect, through non-linear coupling between TMs and RWMs, of feedback on the TMs or to a reduced plasma-wall interaction affecting the plasma flow rotation. Electromagnetic torque calculations show that with active feedback stabilization the TMs amplitude remains well below the locking threshold condition for a thick shell. Finally, it is suggested that active feedback stabilization of RWMs and current profile control techniques can be employed simultaneously thus improving both the plasma duration and its confinement properties.
EXTRAP T2R逆磁箍缩中，多个电阻壁模（RWMs）的有源反馈稳定已被成功验证。在采用有源反馈稳定的等离子体放电中，除了放电持续时间延长之外，一个特征是等离子体旋转的维持。对于内部共振撕裂模（TMs）以及本征杂质离子，均观察到旋转的持续维持。两者的环向旋转速度之间存在良好的一致性：环向旋转表现为一个加速阶段，随后在一个壁时间之后进入减速阶段，且减速阶段比标准放电中更慢。TMs与杂质离子沿相同的极向方向旋转，且速度相近。极向和环向速度具有相当的幅度，其径向分布的一个简单模型再现了螺旋相位速度的主要特征。RWMs的反馈稳定并未定性改变TMs的行为，诸如发电机效应和“slinky”模式等典型现象仍可观察到。等离子体及TMs旋转的改善维持，即使在反馈仅作用于内部非共振RWMs时也能实现。这可能归因于反馈通过TMs与RWMs之间的非线性耦合对TMs产生的间接正效应，或由于等离子体-壁相互作用减弱而影响了等离子体流旋转。电磁力矩计算表明，在有源反馈稳定下，TMs的幅度远低于厚壁条件下的锁定阈值。最后，建议将有源反馈稳定RWMs与电流分布控制技术相结合，可同时改善等离子体持续时间及其约束性能。