Resumen de A Monte Carlo code to optimize the production of radioactive ion beams by the isol technique

Mario Santana Leitner

• Currently the nuclear chart includes around 3000 nuclides, distributed as beta(+-)-emitters, stable and spontaneously fissioning isotopes. A similar amount of unknown nuclei belongs to the so-called terra incognita. The exploration of this zone is to be assisted by the use of radioactive ion beams and could provide a new understanding of several nuclear properties.

  Moreover, besides pointing at crucial questions such as the validity of the shell model, the dilute matter and the halo structure, challenging experiments outside nuclear physics are also attended, e.g., explanations of the nucleosythesis processes that justify the constitution of the universe.

  These, together with other fascinating research lines in particle physics, solid state physics and medicine, demand utterly exotic and intense ion beams for which a global optimization of all relevant phenomena in beam formation has to be coherently conducted. As a response to this request, a Monte Carlo code, RIBO (Radioactive Ion Beam Optimizer) has been written, to integrate diffusion and effusion under various pressure flows and conditions, including the transport through continuous media and enabling diffractive and surface dependent effects, emulating ionization in surface and plasma ion sources and, finally, reproducing the movement of ions under electro-magnetic fields.

  The 1st part is devoted to the implementation of the models, the 2nd applies the resulting program to the analysis of the most important target morphologies.

  1st PART:

  The mathematics of DIFFUSION is treated from the point of view of isotope migration within a bulk target. A diffusion package is developed, tested and applied to typical cases to decouple the effect of gradients of temperature or concentration and of the beam time structure.

  The implementation of EFFUSION is preceded by a discussion of surface-atom interactions and of the regime of validity of the available models. Diffusive collisions are