Kortshagen U, Bhandarkar U
Department of Mechanical Engineering, University of Minnesota, 111 Church Street Southeast, Minneapolis, Minnesota 55455, USA.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 1999 Jul;60(1):887-98. doi: 10.1103/physreve.60.887.
In this paper we study the growth of nanometer particles in low pressure plasmas due to coagulation. We describe results of a model which involves the self-consistent determination of plasma properties, the description of particle charging, as well as the description of the particle size distribution via solution of the general dynamic equation for an aerosol. Our results show that particle coagulation in the low pressure plasma is enhanced compared to coagulation in neutral aerosols due to the attraction of oppositely charged particles. The temporal behavior of the coagulation follows the same laws as coagulation of neutral particles as long as the density of nanometer particles is larger than the positive ion density in the plasma. The positive ion density can be considered as the critical density for coagulation to occur. We also show that the details of the particle charging mechanism are only of minor importance for the coagulation dynamics but of great importance for the accurate prediction of plasma parameters.
在本文中，我们研究了低压等离子体中由于凝聚作用导致的纳米颗粒生长。我们描述了一个模型的结果，该模型涉及等离子体性质的自洽确定、颗粒充电的描述，以及通过气溶胶的一般动力学方程的解来描述颗粒尺寸分布。我们的结果表明，由于带相反电荷颗粒的吸引力，低压等离子体中的颗粒凝聚相较于中性气溶胶中的凝聚得到增强。只要纳米颗粒的密度大于等离子体中的正离子密度，凝聚的时间行为就遵循与中性颗粒凝聚相同的规律。正离子密度可被视为发生凝聚的临界密度。我们还表明，颗粒充电机制的细节对于凝聚动力学而言仅具有次要重要性，但对于准确预测等离子体参数却极为重要。
