Acoustic signature: study of the damping induced by irradiation damage

The acoustic signature V(z) obtained by acoustic microscopy has been intensively studied for the past fifteen years. If the Rayleigh wave velocity parameter is easily obtained, it is much more difficult to extract its damping from the V(z). To illustrate the evolution of this parameter, we have investigated the damage process induced by irradiation on steel in nuclear power plant. Experimental results at different frequencies show a good agreement with theory on irradiation dependence of Rayleigh wave velocity and attenuation. This method is also able to evaluate some mechanical properties and to estimate the density and size of cracks of irradiated materials