Electromagnetic Scattering by Charged Dust Aggregates

Dust aggregates in plasma charge, which makes it difficult to study the propagation of electromagnetic wave in it. While in order to study the influence of charged dust to the space detection, some work must be done for the electromagnetic characteristic of it. Based on discrete dipole approximation (DDA), electromagnetic scattering characteristic of charged dust aggregates is studied. At the beginning, DDA theory and expressions of scattering coefficients by a single charged sphere are introduced simply. Nextly, considering the influence of charges, the polarization of each dipole in DDA method is corrected by scattering coefficients of charged sphere. Thirdly, the models of charged dust aggregates we using are simulated by two different methods. Thus, combing the correction polarization index with the DDSCAT package, the scattering intensities of a plane wave by charged dust aggregates can be calculated, and the influence of quantity of electricity, which we express it as surface conductivity , to the scattering fields of it can also be analyzed in detail. The study of electromagnetic scattering by charged dust aggregates will play an important role in the atmospheric optics, astrophysics, remote detection and other fields.