PIIM, UMR6633 CNRS/Université de Provence, case 321, centre universitaire de Saint-Jérôme, Marseille, France.
Phys Rev Lett. 2011 Jun 3;106(22):225006. doi: 10.1103/PhysRevLett.106.225006.
The frequent situation where a strongly nonlinear rotating structure develops in a linear magnetized plasma column is investigated experimentally with emphasis on the ion velocity distribution function (IVDF). Most often, a mode m=2 appears exhibiting a large density and potential perturbation with angular frequency slightly above the ion cyclotron frequency. For the first time the spatiotemporal evolution of the IVDF is studied using time-resolved laser induced fluorescence to explore the ion's interaction with the nonlinear wave propagating inside the column and at the origin of plasma transport outside the limiter. The ion fluid exhibits an alternance from azimuthal to radial velocity due to the electric field inside the rotating structure. A fluid model also allows us to locally reconstruct the self-consistent electric field evolution which contradicts all existing theories.
研究了在线性磁化等离子体柱中频繁出现的强非线性旋转结构的情况，重点研究了离子速度分布函数（IVDF）。通常情况下，模式 m=2 会出现，表现出较大的密度和电势扰动，角频率略高于离子回旋频率。首次使用时间分辨激光诱导荧光研究了 IVDF 的时空演化，以探索离子与在柱内传播的非线性波以及在限流器外的等离子体输运起源处的相互作用。由于旋转结构内的电场，离子流体会交替出现角向速度和径向速度。流体模型还允许我们局部重建自洽电场的演化，这与所有现有理论都相矛盾。
