The subject of radiation damage in silicon by plasma and electron beam technique has been investigated for many years. Modification for having particular surface topography is also sometimes desired specially in those experiments that ion interaction with surface is very sensitive to the surface topography. In our previous work in order to study the electron bombardment effect on silicon, we used our new design electron source. In this paper, silicon samples were bombarded by 30 keV argon ions on normal to the surface with doses in the 1×1016-2×1017 Ar+/cm2 range. Topographical changes induced on silicon surface, generation of blisters and evolution of them at different doses observed by atomic force microscopy. Measurement of mean surface height show that for doses greater than 1×1017 Ar+/cm2 the height decreases because of sputtering. The optical properties of samples after Ar+ irradiation measured by a UV-Vis-NIR spectrophotometer.