On the Scattering of Electromagnetic Waves by a Charged Sphere

Scattering of electromagnetic radiation by a charged homogeneous spherical particle/body is treated. Theoretical solution represents a generalization of the Mie’s scattering theory for electrically neutral sphere. It is shown that classical and quantum physics approaches may lead to different conclusions, as documented by numerical computations assuming various permeabilities, refractive indices, surface charges, temperatures, and other physical parameters of the spherical particles. Two discrete wavelengths (5μm and 1 mm) of the incident radiation are considered. Optical properties of charged particles composed of absorbing and slightly absorbing materials can essentially differ. Especially, the resonance peaks typically occur when imaginary part of particle refractive index is low. The relative permeability of a material may differ from unity at large wavelengths, e.g., in microwave region. Basically, the relative permeability appears to be less important factor than the surface charge. However, the permeability can influence the scattering and extinction efficiencies, as well as the backscattering features of small particles, under some conditions. Received 27 July 2010, Accepted 19 September 2010, Scheduled 1 October 2010 Corresponding author: M. Kocifaj ([email protected]). 18 Klačka and Kocifaj