Excitation of surface currents on a plasma-immersed cylinder by electromagnetic and electrokinetic waves. I. The vacuum sheath

摘要

The surface currents excited on an infinitely long, circular metal cylinder immersed in an isotropic compressible plasma by electromagnetic (EM) and electrokinetic (EK) plane waves are investigated. The formulation proceeds from velocity moments of the collisionless Boltzmann equation for the electrons, together with Maxwell s equations, and uses a linearized analysis. The sheath which forms about the cylinder is approximated by a free-space layer between the cylinder and the uniform plasma, called the vacuum sheath. It is found from the numerical calculations that the vacuum sheath tends to screen the EK wave from the cylinder, and produces a large attenuation of the surface currents excited by the EK wave. The sheath and EK wave are found, on the other hand, to negligibly affect the currents excited by the EM wave.