Time dependence of multiply scattered diffuse ultrasound in polycrystalline media
نویسندگان
چکیده
Time dependence of multiply scattered diffuse ultrasound in polycrystalline media" (1995). Time domain results are presented for the multiply scattered longitudinal intensity backscattered from a polycrystalline medium. The results are solutions to the ultrasonic radiative transfer equation (URTE), the derivation of which is based upon radiative transfer theory. Unlike steady-state solutions obtained previously, time domain solutions will more closely oarrespond to experiments that use tone burst sources. This paper is concerned with the time dependence of the backscattered longitudinal intensity from a polycrystalline medium excited by a normally incident longitudinal wave idealized as an impulsive deposition of energy. It is shown that multiple scattering effects become significant at times on the order of a mean free time or less. It is anticipated that this work may be applicable to microstructura characterization of polycrystalline, geophysical and other random media in which multiple scattering effects are important.
منابع مشابه
Radiative transfer and multiple scattering of diffuse ultrasound
Radiative transfer and multiple scattering of diffuse ultrasound" (1994). Faculty Publications from the Department of Engineering Mechanics. Paper 6. A model is presented for the mtltiply scattered incoherent field in a continuous polycrystalline elastic medium. Unlike a previous, development based upon energy conservation considerations [J.] for a medium containing discrete random scatterers, ...
متن کاملUltrasonic radiative transfer in polycrystalline media: Effects of a fluidâ•fisolid interface
Ultrasonic radiative transfer in polycrystalline media: Effects of a fluid–solid interface" (1995). In previous derivations of the ultrasonic radiative transfer equation ͑URTE͒ for the modeling of multiply scattered diffuse ultrasound in polycrystalline media, the boundary conditions appropriate to experiments performed in a water bath were not used. In the present work, this fluid–solid boundary...
متن کاملImaging in diffuse media with pulsed-ultrasound-modulated light and the photorefractive effect.
Acousto-optic imaging in diffuse media is a dual wave-sensing technique in which an acoustic field interacts with multiply scattered laser light. The acoustic field causes a phase modulation in the optical field emanating from the interaction region, and this phase-modulated optical field carries with it information about the local optomechanical properties of the media. We report on the use of...
متن کاملCorrelation transfer equation for ultrasound-modulated multiply scattered light.
In this paper, we develop a temporal correlation transfer equation (CTE) for ultrasound-modulated multiply scattered light. The equation can be used to obtain the time-varying specific intensity of light produced by a nonuniform ultrasound field in optically scattering media that have a heterogeneous distribution of optical parameters. We also develop a Monte Carlo algorithm that can provide th...
متن کاملRadiative transfer of ultrasound
A radiative transfer equation is used to model the diffuse multiple scattering of ultrasound in a medium containing discrete random scatterers. An assumption of uncorrelated phases allows one to write an equation of energy balance for the diffuse intensity. This ultrasonic radiative transfer equation contains single-scattering and propagation parameters that are calculated using the elastic wav...
متن کامل