Electrostatic Potential of a Test Particle in Multicomponent Plasma

Abstract

In this dissertation, the electrostatic potential (¢) of a test charged particle in a multicomponent plasma has been calculated by solving the linearized Vlasov-Poisson's system of equations. First, we have calculated the electrostatic potential by using initial value problem by applying Fourier and Laplace tmnsform methods. Then, we calculated ¢ by using the test charge appTOach, applying space time Fourier and Laplace transform method. It was observed that fo r a slowly moving test charge (compared with the thermal velocity of electrons and ions), the test charge is shielded both by electrons and ions. On the other hand, for a fast moving test char'[Je (compared with the thermal velocity of electrons), no shielding was observed. For a test charge moving with intermediate speed (greater than the thermal velocity of ions but smaller than the thermal velocity of electTOns), it was observed that only electrons are taking part in the shielding process. Next, we extended these calculations for a multicomponent dusty plasma which in addition to the electrons and ions also contains dust particles. Cooper(Phys. Fluids, 12, 2707(1969)/ has calculated the electrostatic potential of a slow test charge particle by using partial wave decomposition and showed that the electrostatic potential of a slow test charge in electTon-ion plasma varied as 7,-3 for large T. Extending his work, we have calculated an analytical expression for the electTOstatic potential of a test charge in multicomponent dusty plasma. We have found that outside the Debye sphere, the electTOstatic potential also varies as 1'-2 in addition to the 7.- 3 . We have also nume7'ically calculated the electrostatic potential for the near and far-field, and are plotted against the normalized distance. Finally, we have compared the analytical and numerical results. The relevance of this kind of work for space and laboratory plasma has also been pointed out.