Thermally activated transport of a dislocation loop in terms of a line-tension model, where the dislocation line was assumed to be a flexible string, was reported. According to conventional rate theory, the features of thermal activation were determined by the saddle-point geometry in high-dimensional configuration-space. If the circumference of a dislocation loop, L, was longer than a critical length, Lc, the selected saddle-point configuration was the well known double-kink type solution. On the other hand, the manner of the thermal activation of a dislocation loop shorter than Lc was rather point-defect-like. Here, attention was paid to the temperature-dependence of the transition-rate which was represented by an Arrhenius-type expression in which the pre-exponential factor depended upon temperature according to a reciprocal square-root relationship, for sufficiently long dislocation loops, on the basis of the analysis.

Thermally Activated Transport of a Dislocation Loop within an Elastic Model. K.Ohsawa, E.Kuramoto: Journal of Nuclear Materials, 2007, 367-370[1], 327-31