ELECTRON BEAMS

Author: ANTONICCI ANNA.
Year: 2004.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE CIENCIAS FÍSICAS.
Place of preparation: FACULTAD CIENCIAS FÍSICAS.

Summary: This thesis falls in the field of fusion research by confirmamiento inertial and specifically in the framework of the ignition rápida.Hemos developed a numerical study of the experimental results obtained on a fundamental aspect of the scheme: the transport of Quick electrons generated by lasers ultra-intensos.En the past few years have yielded important information relating tothe characteristic parameters of the spread and deposition of energy of these electrons, however only type numerical studies, conducted through appropriate codes simulation can clarify all the physical processes involucrados.De fact different mechanisms influence at the same time on transport: collisions, inductive electromagnetic fields and fields electrostáticos.Actualmente codes hybrid simulation, which includes a model colisional calculating autoconsistente of electromagnetic fields, fields can be described only inductive and assuming geometries simplificadas.Por this reason we have developed a code the first hybrid Monte Carlo (Petra) to study the effects colisionales and the effects of electromagnetic fields inductive, assuming approximate standard density total induced on the means of transport equals zaro.Segundo have begun to study the effects colisioonales and effects of the fields electromagnétifcos inductive, assuming the standard density approximation of total load induced on the means of transport like zero.Segundo have begun to study the effects of the separation of transient load induced as a result of the rapid spread of electrons and the effects of electrostatic fields that generan.Por means of Petra have mainly studied the experimental results obtained on the range of propagation characteristic and average energy electrons fast, in the laboratory LULI, media densos.El resutado most obvious obtained is the role imortante played by inhibition on the electrical transport of electrons in rapid materiale dieléctricos.Para these prove to be very important adequate description the resistivity effective, while nuestos results suggest that the spread in conductive materials can be roughly described by simple models colisionales.Al analyzing experimental results on the spread of electrons in gases, it is clear that it is not possible to use the model of Petra, because it is based on the fundamental assumption that a significant flow of return is induced in plasma background and is able to compensate for the flow of electrons rápidos.En gas flow return is not generated easily and the effects of separation load and then the fields electrostásticos are very important. That is why we have developed a code Vlasov describing the dynamics of both populations eclectrones (rapid plasma and background) and the evolution of the field electrostatic inducido.Actualmente have done a code in 1D, which No one despises first order approximation of the effects ionization field, a major low point of view of energy balance, but instead instant low viewpoint dela dinámica.El agreement with the experimental data found on the range and speed of penetration of fast electrons in gases our interest is satisfactory and future will develop the model into 2D and include l adescripción of macanismo ionization field.