Atomic displacements and defect accumulation during irradiation with energetic particles: An autobiographical review

We have been requested to prepare a rather unusual article for this special publication. The article should be not only autobiographical in nature but should also have historical perspectives and critique and should contain some element of visionary forecast. Undoubtedly, the idea is unique and challenging though may prove to be less than easy to realise! In response to this challenge, I will at least attempt to present a kind of cohesive description of the evolution of my research activities in the field of defect production, diffusion, interactions and accumulation. These activities have involved widely different irradiation conditions, extending from 1 to 225 MeV electrons, fission to fusion neutrons and 3–800 MeV protons. Over the years, I have also been involved in a variety of theoretical activities dealing with different aspects of defect production, diffusion, void/bubble nucleation, kinetics of damage accumulation and irradiation hardening and embrittlement. An overview of these activities and their main conclusions will be presented. It is somewhat surprising that even after 25 years of continuous involvement, I still find myself grappling with basically similar sorts of problems in the same field of research. In hindsight, it may appear as if all the activities that I have been involved in might have been carefully planned well in advance. The reality is, however, that «chance» and «circumstance» have actually dictated the course of events. With this experience in hand, I hesitate to venture into the lands of unknowns, and shall refrain from making visionary forecast about what future may or may not unfold in its own time!