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Title: Thermonuclear targets for direct-drive ignition by a megajoule laser pulse

Journal Article · · Journal of Experimental and Theoretical Physics
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  1. Russian Federal Nuclear Center, All-Russia Research Institute of Experimental Physics (Russian Federation)
  2. Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)
  3. Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation)

Central ignition of a thin two-layer-shell fusion target that is directly driven by a 2-MJ profiled pulse of Nd laser second-harmonic radiation has been studied. The parameters of the target were selected so as to provide effective acceleration of the shell toward the center, which was sufficient for the onset of ignition under conditions of increased hydrodynamic stability of the ablator acceleration and compression. The aspect ratio of the inner deuterium-tritium layer of the shell does not exceed 15, provided that a major part (above 75%) of the outer layer (plastic ablator) is evaporated by the instant of maximum compression. The investigation is based on two series of numerical calculations that were performed using one-dimensional (1D) hydrodynamic codes. The first 1D code was used to calculate the absorption of the profiled laser-radiation pulse (including calculation of the total absorption coefficient with allowance for the inverse bremsstrahlung and resonance mechanisms) and the spatial distribution of target heating for a real geometry of irradiation using 192 laser beams in a scheme of focusing with a cubo-octahedral symmetry. The second 1D code was used for simulating the total cycle of target evolution under the action of absorbed laser radiation and for determining the thermonuclear gain that was achieved with a given target.

OSTI ID:
22472025
Journal Information:
Journal of Experimental and Theoretical Physics, Vol. 121, Issue 4; Other Information: Copyright (c) 2015 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
Country of Publication:
United States
Language:
English