Advanced Photon Research Center, Japan Atomic Energy Agency, Kizugawa, Kyoto 619-0215, Japan.
Phys Rev Lett. 2010 Sep 24;105(13):135002. doi: 10.1103/PhysRevLett.105.135002. Epub 2010 Sep 23.
Ultraintense laser pulses propagating in near-critical density plasmas generate magnetic dipole vortex structures. In the region of decreasing plasma density, the vortex expands both in forward and lateral directions. The magnetic field pressure pushes electrons and ions to form a density jump along the vortex axis and induces a longitudinal electric field. This structure moves together with the expanding dipole vortex. The background ions located ahead of the electric field are accelerated to high energies. The energy scaling of ions generated by this magnetic vortex acceleration mechanism is derived and corroborated using particle-in-cell simulations.
超强激光脉冲在近临阈密度等离子体中传播会产生磁偶极涡旋结构。在等离子体密度降低的区域，涡旋在向前和侧向两个方向上扩展。磁场压力推动电子和离子在涡旋轴线上形成密度跃变，并感应出纵向电场。这个结构与扩展的磁偶极涡旋一起移动。位于电场前方的背景离子被加速到高能状态。利用粒子模拟验证并推导出了这种磁涡旋加速机制产生的离子能量标度。
