Dislocation damping and defect dragging in aluminum: the slow modulus effect

Dislocation damping and Young’s modulus changes were measured on aluminum irradiated at low temperature by 1‐MeV electrons. These measurements, taken at fixed temperatures, demonstrate good agreement with the prediction of the defect dragging model proposed by Simpson and Sosin and provide quantitative support of the model. Good agreement with the theoretical results is also obtained following interrupted electron‐beam bombardments which take into account the temperature‐dependent background damping. The very slow change in modulus reported earlier was studied further and it is shown that this slow change can be fully understood simply within the framework of the defect dragging model.