FIREX Project and Effects of Self-generated Electric and Magnetic Fields on Electron Driven Fast Ignition

Journal Article · Tue Nov 23 00:00:00 EST 2010 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3526161· OSTI ID:21506919

Mima, Kunioki ^[1]; Sunahara, A; Shiraga, Hiroyuki; Nishimura, H; Azechi, H; Johzaki, T; Nagatomo, H ^[1]; Garcia, C; Veralde, P ^[2]

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1. Institute of laser Engineering, Osaka University (Japan)
2. Institute of Fusion Nuclear, Universiy Politecnica de Madrid (Spain)

The fast ignition is a new scheme in laser fusion, in which higher energy gain is expected with smaller laser pulse energy. The cone target has been introduced for realizing higher coupling efficiency. At ILE, Osaka University, the laser with 4 beams and the total output of 10kJ/ps: LFEX has been built and we have started the integrated experiments. The experiments showed that the coupling efficiency is degraded because of the laser pre-pulse. Namely, the main pulse is absorbed in a long scale pre-plasma produced by the pre-pulse and hot electron energy is higher than that for a clean pulse. Furthermore, the distance between the hot electron source and the core plasma is long. So, we are exploring how to overcome the pre-pulse effects on the cone target. The next series of experiments is planned for this fall. In these experiments, the LFEX pre-pulse level will be reduced and advanced targets for mitigating the pre-pulse effects will be introduced.In this paper, it is proposed that a thin foil cover the laser entrance of a cone to mitigate the pre-plasma and a double cone reduce loss of high energy electrons from the side wall of the cone. The simulations indicate that higher coupling efficiency is expected for the double cone target with a thin foil on the laser entrance. Namely, the pre-pulse will be absorbed by the foil and the electro-magnetic fields generated on the surface of the inner cone will confine high energy electrons. The goal of the next series of experiments will be high coupling efficiency to heat a compressed plasma to temperatures higher than 2 keV.

• OSTI ID: 21506919
• Journal Information: AIP Conference Proceedings, Vol. 1308, Issue 1; Conference: International symposium on waves, coherent structures and turbulence in plasmas, Gandhinagar (India), 12-15 Jan 2010; Other Information: DOI: 10.1063/1.3526161; (c) 2010 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ABLATION
BEAMS
COUPLING
EFFICIENCY
ELECTRON SOURCES
ELECTRONS
FOILS
FOKKER-PLANCK EQUATION
GAIN
HEAT
KEV RANGE
MAGNETIC FIELDS
PLASMA
PLASMA DENSITY
PULSES
SIMULATION
SURFACES
X RADIATION
AMPLIFICATION
DIFFERENTIAL EQUATIONS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENERGY
ENERGY RANGE
EQUATIONS
FERMIONS
IONIZING RADIATIONS
LEPTONS
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLE SOURCES
RADIATION SOURCES
RADIATIONS