Description: A brief summary of the history of research in the fields of radiation damage, point defects, and dislocation effects is presented. Theory and previous experiments are discussed. Apparatus capable of continuously measuring changes in the elastic modulus and internal friction during gamma irradiation over the temperature range from <4 deg K to well above room temperature is described. A novel hollow-cylinder sample geometry permits use of a source strength of only 1 Ci. Survey experiments over a wide temperature range and isothermal irradiations above room temperature are discussed. Results are explained in terms of the KoehlerGranato- Luecke vibrating-string dislocation model and the Thompson- Buck- Huntington- Barnes defect-dislocation interaction model. Consistent results are obtained under the assumptions of wide dislocation splitting and the presence of two dislocation components. Long-range migration appears to-occur first in Stuge I in silver. The activation energy for the observed Stage III annealing is about 0.48 eV. The responsible defect is most likely the single interstitial atom. Pipe diffusion is necessary to explain the results. The trapping efficiency of dislocations could not be determined because of the presence of more than one dislocation component. (27 figures, 9 tables, 157 references) (DLC)
Date: November 14, 1973
Creator: Van Konynenburg, R.A.
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Partner: UNT Libraries Government Documents Department