A JEM 200A electron microscope has been linked to a 120 kV heavy-ion accelerator in order to observe the dynamic effects of heavy-ion bombardment of materials. The ions, produced in a sputtering ion source, are accelerated, analysed, directed through a flight line and then deflected to strike the specimen in the electron microscope. The effects of the ion bombardment on the specimen are recorded on videotape as they occur. Details of the system and examples of its use are presented.