The advent of ultra-intense and ultra-short soft X-ray sources has generated a major scientific leap. Free Electron Lasers (FELs), High Harmonic Generation (HHG) and laser-driven X-ray sources allow researchers to create and study exotic states of matter or to record images in 3D with femtosecond and angstrom resolution. My research project will focus on nano- femto- coherent imaging (diffraction and holography). Exciting applications are developed nowadays in this field: coherent imaging of biological samples or real-time study of the laser-induced ultra-fast demagnetization of magnetic nanostructures. Still, the development of these applications is in "exploratory" phase: reconstruction algorithms need images of excellent quality to converge to a solution, which is not possible to obtain in a quotidian way. The high intensity (~10^18 W cm-2) damages the sample, creating a plasma that will cause image blurring and loss of resolution. These a priori unknown contributions to the diffraction/holographic pattern must be taken into account to prevent artefact generation. The project aims at developing a 3D Maxwell-Bloch code using advanced techniques to model the non-linear interaction of X-ray radiation with living or inert nano-objects or plasma. Moreover, other different applications are foreseen, as research and development of plasma-based seeded soft-X ray lasers. I have a long experience as a developer and user of such complex codes (2D plasma hydrodynamics, 3D ray-tracing and 1D Maxwell-Bloch codes) being adequate to carry out this project. I will take advantage of the environment where the project will be carried out, since the Instituto de Fusión Nuclear has the knowledge and expertise in several fields (atomic physics, parallel supercomputing) that will be essential for succeeding. In addition to this, I will be able to create a small research group around this project, by supervising some engineering students.