倾斜磁场下尘埃等离子体的各向异性扩散

Anisotropic Diffusion of Quasi—two—dimensional Complex Plasmaunder Inclined External Magnetic Field

利用郎之万动力学模拟方法,研究了二维尘埃等离子体的扩散特性.校正结果显示该模拟程序能够准确再现实验结果.进一步模拟表明,倾斜磁场使得系统在二维平面上呈现出各向异性扩散特征,当粒子所受垂直方向的洛伦兹力与壳层电场力平衡时,系统各向异性扩散特征消失.同时发现,中性碰撞力将会极大延长各向异性扩散存在的时间.

Based on the Langevin dynamics simulations,the diffusion of the quasi-two-dimensional(Q2D)complex plasma exposed to an inclined external magnetic field is investigated.It is shown that the inclined external magnetic field gives rise to an instant anisotropic diffusion of the charged particles within the Q2D simulation plane,and the isotropic diffusion is recovered after the Lorentz force perpendicular to the Q2D simulation plane is balanced by the self-consistent force in the sheath.Further investigations show that the stronger collisions between neutral gas and charged particles delay the recovery of isotropic diffusion.