Structure and transportation of electron vortices in near-critical density plasmas driven by ultrashort intense laser pulses have been studied by multi-dimensional particle-in-cell simulations. Dimensional features of electron vortices are revealed. In two-dimensional geometry, two electron vortices and a quasi-static magnetic dipole are closely coupled. In three-dimensional geometry, a moving electron vortex ring associated with a closed magnetic ring moves in near-critical density plasmas. Such structure can transport some energy to the region where the laser pulse cannot reach. It is found that the motion of plasma ions makes the vortex magnetic energy dissipate quickly. These studies provide possible connection of electron vortices in nature with laser plasma experiments.

已通过多维粒子胞内模拟研究了由超短强激光脉冲驱动的近临界密度等离子体中电子涡流的结构和传输。揭示了电子涡旋的尺寸特征。在二维几何中，两个电子涡旋和一个准静态磁偶极子紧密耦合。在三维几何中，与闭合磁环相关联的移动电子涡环在接近临界密度的等离子体中移动。这种结构可以将一些能量传输到激光脉冲无法到达的区域。发现等离子体离子的运动使涡旋磁能快速消散。这些研究为自然界中的电子涡流与激光等离子体实验提供了可能的联系。