Scattering Of Electromagnetic Wave By Charged Sand Particle

You-He Zhou et al.have found that,partially charged particles in sand storm can attenuate incident electromagnetic wave.In this paper we put effort to preliminary results on the mechanism of the effect of charged sand particle on electromagnetic wave.Based on Mie’s scattering theory,we calculate the scattering of electromagnetic wave by charged sand particle,which is charged in different model and/or has different charged areas.We mainly talk about the results of which particle is charged uniformly or in cosine model,and the charged area centers on different direction—the symmetry axis of charged area is parallel to the direction of the propagation,the direction of the electric component,or the direction of the magnetic component of the electromagnetic wave respectively.The origin of the coordinate locates on the center of the charged particle.The results show that:1.The smaller the particle is,the low the frequency of the incident wave is,or the smaller the size parameter of particle is,the effect of charged particle on electromagnetic wave is larger,no matter in which model the particle is charged.The effect of charged particle on electromagnetic wave does not vary monotonically with the increase of charged area.2.The scattering of electromagnetic wave by charged particle varies quite differently when the charged area of particle locates on different directions.When the symmetry axis of charged area is parallel to the direction of propagation of the incident electromagnetic wave,the scattering results are large.And when the symmetry axis of charged area is perpendicular to the propagation direction,the results are relatively rather smaller.3.When the particle is charged in different models,the scattering of electromagnetic wave presents differently.For the same quantity of charge,the extinction efficiency is larger when particle is charged in cosine model than that when particle is charged uniformly.And the difference of extinction efficiencies increase with the increase of charged area.And with the same charge quantity,when particle is charged in cosine model,the scattering efficiency is smaller than that when particle is charged uniformly,when charged area is small—charge angle is less than 100 degree.And when charge angle is greater than 100 degree,the scattering efficiency is larger when particle is charged in cosine model.4.The excess surface charge oscillates under the effect of incident electromagnetic wave.It absorbs and radiates electromagnetic energy in all directions,this leads to the change of electromagnetic wave.The existence of the surface charge not only can enhance the effect of scattering/extinction on electromagnetic wave by charged particle,but also can attenuate the effect of scattering/extinction.