Fission-Fragment Damage in Gold Films

Abstract

The effects of fission‐fragment irradiation on evaporated single‐crystalline gold films have been studied by transmission electron microscopy. The outstanding feature observed after irradiation is the appearance of black spots of 20 to 300 Å in diameter. These images are diffraction effects caused by damage regions and their surrounding strain field. It is believed that the damage regions are produced by energetic primaries. In some instances the defects could be identified as triangular dislocation loops on (111) planes. Dark‐field observations indicate that defects with a compressive as well as defects with a tensile strain field are present. From determinations of the density of spots it is concluded that the average fission fragment produces 25 spots along its path in gold.