ON MODIFICATION OF THE ORBITAL MOTION LIMITED METHOD FOR TREATING POLARIZATION EFFECTS IN THE PROCESS OF DUST PARTICLE CHARGING IN PLASMAS
It is known that the orbital motion limited method, being applied to dusty plasma, suggests that the particles of the plasma medium, namely electrons and ions, are independently absorbed by a dust grain. It is also assumed in the classic version of the orbital motion limited method that the interaction of the charged plasma particles with the dust is purely Coulomb, which means complete disregard of field screening phenomena. Such assumptions are only valid if the size of the dust particle is much smaller than the characteristic screening radius, which in turn is much less than the mean free paths of the electrons and ions in the plasma. In this case, application of the conservation laws of energy and angular momentum is enough to calculate the absorption cross section of electrons and ions by the dust particle. Herein an attempt is made to take into account the polarization of the dust particle itself in its interaction with the plasma particles, and it is shown that the knowledge of the conservation laws of energy and angular momentum turns insufficient. It is demonstrated that the absorption cross sections of electrons and ions of the plasma are determined by the condition that the kinetic energy of the incoming plasma particle should be equal to the maximum of the effective potential energy of their interaction with the dust grain.