Microvoids in Solids: Synchrotron Radiation Phase Contrast Imaging and Simulations

Phase contrast imaging study and computer simulations of microvoids located in solid materials of complex structure have been reported. Images of microvoids arise as interference fringes due to coherent scattering of synchrotron radiation (SR) in matter. In the first part of this work, the simulation of the experimental image of a single tubular microvoid in a SiC crystal to illustrate the advantages and limitations of one-dimensional (1D) phase-contrast method and to discuss the approach to 2D objects has been performed. In the second part, a new iterative method for the variable wave function of radiation is employed to examine the applicability of the phase-contrast method for an array of tubules. The latter method has been shown to be sufficiently accurate to be useful when a number of tubules along the beam is limited. Finally, the interference patterns generated by waves passing through a phantom dentin specimen have been calculated and analyzed. It has been demonstrated that both methods have extensive possibilities to determine the period in the lattice of tubules, even in the presence of some disorder.