Intermittent irradiation techniques, using a high-voltage electron microscope, were improved. It was found to be possible to change the combination of on-times and off-times to the next set without allowing any waiting time. Thus, the undesirable progress of reactions during 2 sets of intermittent irradiation could then be avoided. The usefulness of the technique was demonstrated by making simultaneous measurements of the growth of interstitial-type dislocation loops during irradiation, and of their shrinkage during the interruption of irradiation. The activation energies for the migration of vacancies, and for self-diffusion via a vacancy mechanism, were deduced from a single series of experiments.

S.Arai, C.Morita, K.Arakawa, M.Kiritani: Journal of Electron Microscopy, 1995, 44[1], 1-7