Abstract
Electrostatic interaction of two spherical microparticles in a plasma is studied. An investigation of the interaction between a pointβlike charge and a conducting spherical body in a plasma shows that plasma screening results in decrease a potential barrier as the pointβlike charge approaches the likely charged microparticle, the decrease being more pronounced in case that the microparticle radius is comparable with the Debye screening length. The interaction of two conducting spherical microparticles is considered in the bipolar or bispherical coordinate system for cases of constant charges and constant surface potentials of the microparticles. The latter case firstly considered by us is more suitable to the physics of the electrostatic interaction of microparticles in a plasma where their electrostatic surface potentials are defined by the floating potential of the plasma. The interaction potentials are shown to highly differ in these cases, the electrostatic energy being the interaction potential only in the case of the constant charges independent on the interparticle distance. In the case of the constant surface potentials a work of external sources to sustain surface potentials should be taken into account. By integration of the interaction force calculated using the Maxwell stress tensor, the interaction potential is also defined for the latter case. Approximated analytical expressions for the interaction potential, which are more accurate than the available in the literature, are obtained for both the constant charges and the constant surface potentials (Β© 2009 WILEYβVCH Verlag GmbH & Co. KGaA, Weinheim)