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An Inertial fusion power plant is intended to produce electric power by use of inertial confinement fusion techniques on an industrial scale. This type of power plant is still in a research phase.

It is frequently assumed that the only medium-term perspective (within a few decades) for fusion to get to civilian energy production is the tokamak path, through the ITER international project, by use of magnetic confinement techniques. However, as suggested by various proposals in the inertial fusion field, setting up an inertial fusion energy (IFE) path, simultaneously to the tokamak path, is worth considering.

Overall principles of an IFE reactor

For an easier understanding, it is worth using the analogy of operation between an IFE reactor and a gasoline engine. By applying such an analogy, the process may be seen as a four strokes cycle:

• intake of the fusion fuel (microcapsule) into the reactor chamber;
• compression of the microcapsule in order to initiate the fusion reactions;
• explosion of the plasma created during the compression stroke, leading to the release of fusion energy;
• exhaust of the reaction residue, which will be treated afterwards to extract all the reusable elements, mainly tritium.

To allow such an operation, an inertial fusion reactor is made of several subsets:

Mockup of a golden hohlraum used in laser inertial confinement.

• the injection system, which delivers to the reaction chamber the fusion fuel capsules, and at the same time the possible devices necessary to initiate fusion:
  • the container (hohlraum), intended to take the fuel capsule to a uniform very high temperature, mainly for laser and ion beam confinement techniques;
  • the "wires array" and its power transmission line, for z-pinch confinement technique;
• the "driver" used to compress the fusion fuel capsules; depending on the technique, it can be:
  • lasers;
  • an ion beam accelerator;
  • a z-pinch device;
• the reaction chamber, built upon:
  • an external wall made of metal;
  • an internal blanket intended to protect the external wall from the fusion shockwave and radiation, to get the emitted energy, and to produce the tritium fuel;
• the system intended to process reaction products and debris.

IFE projects

Several projects of inertial fusion power plants have been proposed, notably power production plans based on the following experimental devices, either in operation or under construction:

• in Spain there exists the 4D-Pinch called Pulsotrón;[1]
• in the United States, the National Ignition Facility (laser confinement) and Z machine (z-pinch confinement) experiments;
• in France, the Megajoule laser experiment;
• in Japan (Osaka University), the KONGOH experiment (laser confinment).

As may be noted, only first two of these projects is based on z-pinch confinement, all others being based on laser confinement techniques.

The various phases of such a project are the following^[1] :

• burning demonstration: reproducible achievement of energy release.
• high gain demonstration: experimental demonstration of the feasibility of a reactor with a sufficient energy gain.
• industrial demonstration: validation of the various technical options, and of the whole data needed to define a commercial reactor.
• commercial demonstration: demonstration of the reactor ability to work over a long period, while respecting all the requirements for safety, liability and cost.

At the moment, according to the available data^[2], inertial confinement fusion experiments have not gone beyond the first phase, as well for laser (although it is strongly expected to reach the objectives of the second phase around 2010, when NIF and Megajoule are complete) as for z-pinch (Z machine); these techniques should now demonstrate their ability to obtain a high fusion energy gain, as well as their capability for repetitive working.

Notes and references

1. ^ In the magnetic confinement field, the 2^nd phase corresponds to the objectives of ITER, the 3^rd to these of its follower DEMO, in 20 to 30 years, and the 4^th to those of a possible PROTO, in 40 to 50 years.
2. ^ This chapter is based on data available in June 2006, when Megajoule and NIF lasers are not yet into complete service.

See also

Sustainable development portal

• Nuclear fusion
• Fusion power
• Inertial electrostatic confinement
• Inertial confinement fusion
  • Laser inertial confinement
    • Megajoule laser
    • National Ignition Facility
  • Ion beam inertial confinement
  • Z-pinch inertial confinement
    • Z machine

External links

Generalities about IFE

• La fusion thermonucléaire par confinement inertiel : de la recherche fondamentale à la production d'énergiePDF (1.28 MiB) (Université Bordeaux I, November 2005) (French)
• Tutorial on Heavy-Ion Fusion Energy (Virtual National Laboratory for Heavy-Ion Fusion)
• Summary Report of the 2nd Research Coordination Meeting on the Element of Inertial Fusion Energy Power PlantsPDF (4.82 MiB) (November 2003)
• Review of the Inertial Fusion Energy ProgramPDF (4.14 MiB) (Fusion Energy Sciences Advisory Committee, March 2004)
• Overview of fusion nuclear technology in the USPDF (513 KiB) (June 2005)
• Views on neutronics and activation issues facing liquid-protected IFE chambers
• IEEE-USA Position : Fusion Energy Research & Development (June 2006)

Inertial fusion experimentation sites

• Laser Mégajoule (French)
• National Ignition Facility
• Z-Machine

IFE projects

• Analyses in Support of Z-IFE: LLNL Progress Report for FY-04
• Nineteen Labs, Universities and Industries Collaborating To Produce Energy From ‘Z-Pinch’ Inertial Confinement Fusion
• Z-Pinch Inertial Fusion Energy (presentation of the Sandia National Laboratories Z-IFE project, October 2005)
• Progress on Z-Pinch Inertial Fusion Energy
• Development path for Z-pinch IFE (collective work, April 2005)
• Design Study and Technology Assessment on Inertial Fusion Energy Power Plant (Institute of Laser Engineering, Osaka University)
• The High Average Power Laser Program
• Developing the basis for target injection and tracking in Inertial Fusion Energy power plants (July 2000)