Direct observations of neutron irradiation damage in α-iron

Transmission electron microscopy is used to observe damage in alpha -Fe foils, following irradiation of the foils to total doses of 5 x 10/sup 17/ to 1 x 10/sup 19/ neutrons/cm/sup 2/ (neutron energy above 1 Mev). The irradiations are carried out at 60 deg C. The irradiation damage can be observed directly, in the form of fine black spots, at the highest dose. The extent of the damage can be inferred at the lower doses, however, by observing dislocation production and movement in unirradiated and irradiated samples. (T.F.H.)