Atomic effects of stopping power in planar channeling

Abstract

Using the method of a dielectric function ε in nonuniform many-electron systems, we derive the formula of stopping power for randomly distributed atomic systems under high frequency response. We show the theoretical standpoint of the local density approximation [K. Dan. Vidensk. Selsk. Mat. Fys. Medd. 27 (15) (1953)] precisely, in which there appear the modified Bethe type formula. Using results mentioned above and taking into account of atomic effects of planar channeling, we also develop the theory of stopping power in planar channeled ions. In this approach, channel walls are constructed by discrete lattice atoms. We perform numerical calculations of stopping power for 3 MeV He ions passing through Au atomic planes, and show weaker impact parameter dependences of stopping power from channel plane than results obtained from usual planar continuum model, which have been pointed out by Robinson [Phys. Rev. 179 (1969) 327] since 1969. Through numerical calculations, we show that the modified Bethe type formula gives reasonably quantitative values in planar channeling although those from the usual Bethe type one are overestimated.