Abstract
Iron spheres of μ-size were accelerated by a modified 2 MV Van de Graaff accelerator to velocities from 0.5 to 10 km/sec. With these particles craters were produced in metal targets. The dimensions of the craters were measured by an electron microscope (Stereoscan). Systematical measurements were made for lead, cadmium, silver, copper and aluminum targets. The dependence of the crater diameter, depth and volume as function of the mass and the velocity of the projectile and of the target material is described.