亲电子尘埃在等离子体中带电的PIC方法研究

The charging of electrophilic dust in plasma studied by PIC method

为了考察亲电子效应(包含斥电子效应)对等离子体中尘埃带电的影响,建立了基于粒子网格(particle in cell,PIC)技术的尘埃带电计算方法.在物理上使用表面附加电荷来表征亲电子效应,并在计算方法中增加了相应的数学描述.基于该方法,开展了多个场景例的计算,结果表明:亲电子效应越强,尘埃平衡电荷量就越大,且其平衡电荷量增幅与表面附加电荷面密度有着近似的正比关系;类似地,斥电子尘埃同样具有这种正比关系,但与亲电子尘埃不同的特点是,斥电子尘埃达到平衡电荷量的用时更长;此外,尘埃的粒径越大,亲电子效应所带来的平衡电荷量提升效果就越显著.该方法实现了对等离子体中亲电子尘埃带电的计算能力.通过该方法的计算表明,亲电子材质对等离子体中尘埃带电可以造成影响,且当亲电子效应足够强时,影响效果将不可忽视.

In order to investigate the effect of electrophilic effect(including electron-repellent effect)on dust charging in plasma,a calculation method of dust charging based on particle in cell(PIC)technology is established.Physically using surface-added charge to characterize the electrophilic effect,and the corresponding mathematical description is added in the calculation method.Based on this method,we have carried out calculations of multiple scene examples.The calculation results show that the stronger the electrophilic effect,the larger the dust balance charge.The amplification of dust balance charge has a close proportional relationship with the surface density of surface-added charge.Similarly,the electron-repellent dust also has this proportional relationship.However,unlike the electrophilic dust,the electron-repellent dust takes longer to reach the equilibrium charge.The larger the particle size of the dust,the more significant the effect of the equilibrium charge increase caused by the electrophilic effect.This method realizes the calculation ability of charged electron dust in the plasma.The calculation by this method shows that the electrophilic material can affect the dust charging in the plasma,which cannot be ignored when the electrophilic effect is strong enough.