Observatorio de I+D+i UPM

Memorias de investigación
Electron transport in imploded fast ignition targets
Áreas de investigación
  • Electrónica
Fast ignition involves transport of GA currents of laser-driven electrons through dense coronal plasma of imploded fusion targets [1, 2]. Recently, we have reported integrated simulations of target ignition by fast electrons by means of a hybrid approach that allowed us to investigate important transport features such as current filamentation and magnetic beam collimation simultaneously with ignition physics [3, 4]. In those simulations, we assumed that the electron kinetic energies are given by the ponderomotive scaling and considered an initial divergence half-angle of 22.5º, consistent with the experiments reported in Ref. [1]. We found minimum ignition energies from 25 to 30 kJ, depending on the distance from the cone tip to the compressed core. Assuming a laser-to-fast electron conversion efficiency of 40%, those energies correspond to laser beam energies from 60 to 75 kJ, of the same order than those envisioned for HiPER [5]. Recent experiments carried out at RAL [6] at laser intensities relevant to fast ignition have evidenced an enhancement of the beam divergence with the laser intensity and electron kinetic energies lower than those predicted by the ponderomotive scaling [7]. We have recomputed the ignition energies of fast electron beams taking into account those experimental results. We have taken divergence angles consistent with the experiments of Ref. [6] and mean energies of fast electrons from 1 to 2 MeV. In addition, we have accounted for the scattering of electrons with the cone tip, typically a gold layer of tens of microns, which may induce a beam divergence comparable with those measured in the experiments. In this talk, we will present a parametric study on fast electron energy deposition and actual ignition of an imploded target configuration for different mean kinetic energies and divergences of the relativistic electrons. References [1] R. Kodama et al., Nature 412, 798 (2001) and Nature 418, 933 (2002). [2] R.B. Stephens et al., Phys. Rev. Lett. 91, 185001 (2003). [3] J.J. Honrubia and J. Meyer-ter-Vehn, Nucl. Fusion 46, L25 (2006). [4] J.J. Honrubia and J. Meyer-ter-Vehn, IFSA 2007 Proceedings (2007). [5] M. Dunne, Nature Physics 2, 2 (2006). [6] J.S. Green et al., Phys. Rev. Lett. 100, 015003 (2008). [7] Y. Sentoku et al., IFSA 2007 Proceedings (2007).
Entidad relacionada
35th European Physical Society Conference on Plasma Physics combined with the 10th International Workshop on Fast Ignition of Fusion Targets
Nacionalidad Entidad
Sin nacionalidad
Lugar del congreso
Hersonissos, Creta, Grecia
Esta actividad pertenece a memorias de investigación
  • Participante: J. MEYER-TER-VEHN
  • Autor: Jose Javier Honrubia Checa (UPM)
Grupos de investigación, Departamentos, Centros e Institutos de I+D+i relacionados
  • Creador: Grupo de Investigación: Grupo de Investigación en Fusión Inercial y Física de Plasmas
  • Departamento: Física Aplicada a la Ingeniería Aeronáutica
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