A new effect was observed in Fe following irradiation with 10MeV fullerene beams. Dislocation lines with various shapes were observed in the near vicinity of the projectile path, leading to a strain field that was confined to within a 20 to 40nm diameter cylinder. This was suggested to be due to a high localization of the energy which was deposited during the projectile-slowing process. However, no damage was observed in Ni which was irradiated under the same conditions. The results could be explained by invoking a previously established relationship between the sensitivity of a metal to a high rate of energy-deposition, and the existence of a high-pressure phase in the pressure-temperature phase diagram.

TEM Observations of Iron and Nickel Foils Irradiated by MeV Fullerenes at Room Temperature. H.Dammak, A.Dunlop: Nuclear Instruments and Methods in Physics Research B, 1998, 146[1-4], 285-9