En este trabajo presentamos un modelo para la construcción de un tomógrafo portátil de pocas vistas. Se considera: (1) un tomógrafo de forma circular con 80 cm de diámetro, con imágenes reconstruidas circulares de 20 cm de diámetro. (2) El tomógrafo tiene 6 vistas con 36 conos por vista. Los 216 detectores están fijos sobre la superficie interna del tomógrafo. (3) Las fuentes puntuales están en posiciones fijas. Para la reconstrucción de imagen utilizamos una discretización que considera los caminos de la radiación entre la fuente y el detector, la intersección de estos caminos forman una discretización denominada base natural. El algoritmo de reconstrucción empleado es el r-ART, basado en utilizar la distancia de Bregman como un termino de regularización. La distancia de Bregman es construida con una función convexa que tiene un parámetro r=0.1. Presentamos ejemplos ...

The radiation pathway through a medium where occur the absorption, scattering and emission phenoma is described by the radiative transfer equation (ETR). For purely absorbing media, the dispersion phenomenon is neglected by reducing the ETR to a linear differential equation with analytical solution. For dispersive media, the ETR is a nonlinear differential equation, with non analytical solution and the solution must be approximated by deterministic numerical methods. Monte Carlo is a stochastic method based in probabilities and use random numbers to simulate the occurrence of an event, in this case, the pathways radiation in a participating media. In this study, we have used finite difference and discrete ordinates methods to solve the ETR in one dimension, the results were compared with the Monte Carlo results, Test case results are presented, also the source code used for the solution ...

The Cross-Borehole-Seismic Tomography is a seismic method most used for the determination of subsurface structure of the land. This method involves placing in a borehole the seismic wave generating sources, and in another borehole the receiver as waves detector. The tomographic image reconstructed from Cross-Borehole-Seismic Tomography is obtained by considering a parameter called slowness which is reverse speed with which the seismic waves travel, slowness S varies depending on the geological structure. We consider direct waves traveling from one borehole to another and we obtain an approximation of the following linear system as MS = T , where M is a matrix and is related to the discretization domain, S is the vector formed by the slowness of each discretized domain element and T is the arrival time of the first wave coming from source to detector. For the evaluation of the algorithms ...