Misra A P, Adhikary N C, Shukla P K
Department of Mathematics, Siksha Bhavana, Visva-Bharati University, Santiniketan 731235, West Bengal, India.
Phys Rev E Stat Nonlin Soft Matter Phys. 2012 Nov;86(5 Pt 2):056406. doi: 10.1103/PhysRevE.86.056406. Epub 2012 Nov 26.
We study the effects of ion-dust collisions and ion kinematic viscosities on the linear ion-acoustic instability as well as the nonlinear propagation of small-amplitude solitary waves and shocks (SWS) in a negative-ion plasma with immobile charged dusts. The existence of two linear ion modes, namely the "fast" and "slow" waves, is shown, and their properties are analyzed in the collisional negative-ion plasma. Using the standard reductive perturbation technique, we derive a modified Korteweg-de Vries-Burger (KdVB) equation which describes the evolution of small-amplitude SWS. The profiles of the latter are numerically examined with parameters relevant for laboratory and space plasmas where charged dusts may be positively or negatively charged. It is found that negative-ion plasmas containing positively charged dusts support the propagation of SWS with negative potential. However, the perturbations with both positive and negative potentials may exist when dusts are negatively charged. The results may be useful for the excitation of SWS in laboratory negative-ion plasmas as well as for observation in space plasmas where charged dusts may be positively or negatively charged.
我们研究了离子 - 尘埃碰撞和离子运动粘度对线性离子声不稳定性的影响，以及在具有固定带电尘埃的负离子等离子体中小振幅孤立波和激波（SWS）的非线性传播。展示了两种线性离子模式，即“快”波和“慢”波的存在，并在碰撞负离子等离子体中分析了它们的特性。使用标准的约化摄动技术，我们推导了一个修正的科特韦格 - 德弗里斯 - 伯格（KdVB）方程，该方程描述了小振幅SWS的演化。用与实验室和空间等离子体相关的参数对后者的剖面进行了数值研究，在这些等离子体中带电尘埃可能带正电或负电。研究发现，含有带正电尘埃的负离子等离子体支持具有负电势的SWS的传播。然而，当尘埃带负电时，可能同时存在正电势和负电势的扰动。这些结果对于在实验室负离子等离子体中激发SWS以及在空间等离子体中进行观测可能是有用的，在空间等离子体中带电尘埃可能带正电或负电。
