A simple formula for low-energy sputtering yields

A simple formula for low-energy sputtering yields of elemental targets is presented. The formula follows directly from Sigmund's theory but includes a modified form of the function(M_t/M_p) and an accurate expression for the nuclear stopping cross section. Good agreement with experimental results is obtained for the projectiles Ne, Ar, Kr sputtering not too reactive surfaces at energies 1 keV. Further experiments are suggested as well as theoretical work concerning the meaning of the surface binding energy and the effect of the surface on the sputtering process in general.