The detection and measurement of mechanical strain deflection in hostile environments, including high pressures and temperatures, are limited using standard instrumentation. A method for overcoming these limitations will be studied using nuclear gamma ray resonance, commonly called the "Mossbauer Effect," to measure strain rates. Preliminary studies will be concentrated on developing gamma source counting configurations on room-temperature uniaxial and biaxial (thin-walled tube) strains using sources such as Fe 51 and Co,". The sensitivities of strain-rate measurement will be established, and the effects of elevated temperatures on the emitting source and/or absorber and detector performance will be evaluated. This method can be readily applied to biaxial, slow-moving ("creep") strains such as those experienced in high-temperature nuclear reactor systems, coolant-boundary surfaces.Anticipated Results/Potential Commercial Applications as described by the awardee:Recent ASME Section III Elevated Temperature Code Case problem areas indicate increased need for creep fatigue evaluations, quantitative material stress data, and experimental evidence of such induced strains in reannealed cold-formed parts. The planned technique could do much to provide answers to these and related questions. Other potential applications include: a deep ocean-tide and tsunamidetection warning system, geological and structural displacement measurements, and high-resolution mechanical distortion monitoring.
