Target Physics
Inertial fusion targets can be categorized by the ignition scheme, the implosions mechanism and the driver technology used to supply the compression and the ignition energy. We will briefly review each of these elements. There are two ignition methods currently being considered. The first, called hotspot ignition, heats a central core of the compressed fuel to ignition temperatures. The assembly of a sufficiently large hotspot is accomplished by stagnation of a convergent flow. The assembled configuration of the hotspot, and surrounding compressed, low temperature fuel, will be approximately isobaric. The second ignition technique, called fast ignition, heats cold compressed fuel to ignition temperatures directly with an external source of heat. This technique has become practicable by the advent of short-pulse, high-intensity lasers using chirped-pulse-amplification (CPA), that can compress laser pulses to extremely high power. If focused appropriately, these fast-ignition laser beams can provide the same power densities as result from the hydrodynamic flow stagnation of the first technique. Inertial fusion fuel can be compressed by two techniques, referred to as direct and indirect drive. Directly driven capsules directly absorb energy delivered by the external compression driver and use it to implode the fusion fuel. Indirectly driven targets absorb the external energy in material away from the capsule, which converts it into x-rays. The x rays are contained in a hohlraum fabricated from high atomic weight material, that symmetrizes the x rays. The capsule then absorbs these x-rays to compress the fuel.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 15002770
- Report Number(s):
- UCRL-JC-149377; TRN: US0402358
- Resource Relation:
- Conference: Review for the Snowmass 2002 Fusion Energy Sciences Summer Study, Snowmass Village, CO (US), 07/08/2002--07/19/2002; Other Information: PBD: 20 Jul 2002
- Country of Publication:
- United States
- Language:
- English
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