不对称电极上尘埃等离子体颗粒分布

Distribution of dusty plasma particles on an asymmetrical electrode

针对不对称电极射频(radio frequency,RF)辉光放电,通过构建二维尘埃等离子体鞘层模型,研究了不对称电极附近鞘层电势和电子密度等参量分布,并对鞘层中的颗粒进行受力分析,研究了尘埃颗粒在鞘层中的分布特征.结果表明:不对称电极鞘层附近电势具有棘轮势特点,颗粒受鞘层电场约束悬浮在鞘层内,其所在平衡位置处的电势呈现不对称周期性变化.通过对比不同大小的颗粒,发现小颗粒悬浮在鞘层较高位置成链状分布,大颗粒的平衡高度靠近极板,被“钉”到不对称电极产生的势阱中.

For RF(radio frequency,RF)glow discharge with asymmetric electrode,the distributions of parameters such as the sheath potential and the electron density near the asymmetrical electrode are studied by using a two-dimensional dusty plasma sheath model,and the forces acting on dust particles in the sheath are analyzed to study the distribution characteristics of dust particles in the sheath.Results show that the potential near the sheath of the electrode has the characteristics of ratchet potential.The dust particles are suspended in the sheath by the electric field of the sheath,and the potential at the balance position of dust particles exhibits asymmetrical and periodical change.By comparing the results with different sizes of particles,it is found that the small dust particles are suspended at the higher position in the sheath to form a chain,however,the large dust particles are close to the electrode and are"pinned"to the potential well generated by the asymmetric electrode.