LONG-RANGE EFFECT OF ION-BOMBARDMENT AND ENERGY-TRANSPORT IN SOLIDS

A new mechanism is proposed for describing the long-range effect of io n bombardment in terms of the energy transport in the form of the pote ntial energy of structural defects. The energy thus transferred to a g reat depth may then either be converted into the energy of an elastic wave, which generates secondary defects, or increase the rate of defec t formation, producing static stresses at grain boundaries. The former process occurs at stress-free boundaries. If a grain boundary is unde r stress, the addition of a new defect increases the stress, reducing the energy of formation of the corresponding point defect at the grain boundary. This leads to the generation of point defects at grain boun daries and surfaces. The defects form dislocation loops and eventually , owing to the addition of new point defects, a complex dislocation st ructure.