Reconstruction of Concentration Field around a Growing KDP Crystal Using Direct and Iterative Tomography Algorithms

Reconstruction of concentration field and its gradients around a KDP crystal growing from its aqueous solution using direct and iterative tomography algorithms has been discussed in the present work. The experiments have been conducted in convection‐dominated growth regime. The projection data of the convective field around the growing crystal has been recorded in the form of two‐dimensional schlieren images. Algebraic reconstruction technique (ART) and convolution back projection (CBP) algorithms have been employed for tomographic inversion of the recorded schlieren images and the reconstructions have been performed on select horizontal planes above the growing crystal. The suitability of the overall reconstruction approach has been validated against the results of a simulated convective field in an axisymmetric geometry where full as well as partial projection data are available. The reconstruction results of the experimental projection data show that both the algorithms successfully capture the dominant features of the concentration field and a good overall match between the reconstruction results of the two approaches is seen. However, the computational time for ART is much higher than CBP.