PHYSICAL CONDITIONS AT THE INTERFACE BETWEEN PLASMA AND MATERIAL SURFACE

Various regimes of electric potential variation at the interface betwe en plasma and material surface have been studied. The formal resemblan ce between the Poisson equation and the equation of motion for a class ical particle indicates that no solution may exist in the absence of i on scattering, which would satisfy the boundary conditions selected. W ith an allowance for weak scattering, an oscillatory regime becomes po ssible. As the ion flow velocity increases on approaching the wall, th e oscillatory regime transforms into that described by a monotonic pot ential distribution. The threshold velocity of directed ion motion is found, above which a monotonic potential distribution is possible.