Optimal conditions for shock ignition of scaled cryogenic deuterium-tritium targets

Journal Article · Fri Feb 15 04:00:00 EST 2013 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4792265· OSTI ID:22113458

Lafon, M. ^[1]; Ribeyre, X.; Schurtz, G. ^[2]

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1. Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States)
2. University of Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 33405 Talence (France)

Within the framework of the shock-ignition (SI) scheme, ignition conditions are reached following the separation of the compression and heating phases. First, the shell is compressed at a sub-ignition implosion velocity; then an intense laser spike is launched at the end of the main drive, leading to the propagation of a strong shock through the precompressed fuel. The minimal laser energy required for ignition of scaled deuterium-tritium (DT) targets is assessed by calculations. A semi-empiric model describing the ignitor shock generation and propagation in the fuel assembly is defined. The minimal power needed in the laser spike pulse to achieve ignition is derived from the hydrodynamic model. Optimal conditions for ignition of scaled targets are explored in terms of laser intensity, shell-implosion velocity, and target scale range for the SI process. Curves of minimal laser requirements for ignition are plotted in the energy-power diagram. The most economic and reliable conditions for ignition of a millimeter DT target are observed in the 240- to 320-km/s implosion velocity range and for the peak laser intensity ranging from {approx}2 Multiplication-Sign 10{sup 15} W/cm{sup 2} up to 5 Multiplication-Sign 10{sup 15} W/cm{sup 2}. These optimal conditions correspond to shock-ignited targets for a laser energy of {approx}250 kJ and a laser power of 100 to 200 TW. Large, self-ignited targets are particularly attractive by offering ignition at a lower implosion velocity and a reduced laser intensity than for conventional ignition. The SI scheme allows for the compression and heating phases of the high power laser energy research facility target to be performed at a peak laser intensity below 10{sup 16} W/cm{sup 2}. A better control of parametric and hydrodynamic instabilities within the SI scheme sets it as an optimal and reliable approach to attain ignition of large targets.

• OSTI ID: 22113458
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 2 Vol. 20; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
COMPRESSION
DEUTERIUM
DEUTERIUM TARGET
FUEL ASSEMBLIES
FUELS
HYDRODYNAMIC MODEL
LASER RADIATION
LIGHT TRANSMISSION
PARAMETRIC INSTABILITIES
PLASMA
PLASMA HEATING
SHOCK WAVES
THERMONUCLEAR REACTORS
TRITIUM
TRITIUM TARGET