Erosion of a Surface Interacting with Magnetized Plasma

It is analytically shown that interaction of magnetized multicomponent plasma with a target surface causes an instability of material erosion. The wave numbers and increments of growing fluctuations are determined in a linear approximation. The mean time of surface roughening is of the same order or even shorter than that of the erosion process itself. Erosion instabilities are of importance for long-pulse or steady-state operation of future reactor-grade fusion devices.