[en] Thickening and shrinkage are the well known macroscopic effects which can be observed on carbon stripper foils irradiated with heavy ions. Thickening reduces ion transmission due to larger small-angle scattering. Shrinkage finally results in the rupturing of the carbon foil. There is not much known about the microscopic effects which lead to the obvious macroscopic changes. Therefore slackened carbon stripper foils of about 4 μg/cm² thickness were investigated in order to get more information about the radiation damage. These carbon foils were produced by vacuum evaporation-condensation method and used for heavy ion stripping in a tandem accelerator. Direct knock on collisions of energetic, heavy ions with carbon atoms in the stripper foil are responsible for the radiation damage. Due to the repeated displacements of the carbon atoms, microscopic changes occur which were investigated by electron microscopy. The conclusion of these investigations is that carbon foils with no texture should show better stripper performance. This condition is partly fulfilled by carbon foils produced in a glow discharge process but their mechanical properties and stripper performance is still not good enough. (author)