Equipment for the measurement of elastic after-effect on flexure in metal foils, suited for irradiation experiments

Equipment has been designed for the measurement of elastic after-effect with the purpose of determining anelastic properties of self-interstitial metal atoms, created by low temperature irradiation. Novel use has been made of the capacitive displacement measurement technique, employed on flexure of a sample in foil form. The features of the equipment are high sensitivity in detectable after-effect strength (5 x 10-5) combined with a low loading strain (3 x 10-5), reasonable accuracy, small dimensions of the sample and its holder and the possibility of resistance measurement on the same sample, the latter two especially in relation to irradiation experiments. The equipment has been tested with the Snoek relaxation of interstitially dissolved nitrogen in polycrystalline α-iron; a concentration of 10 at. ppm was easily detectable. (author)