Inertial fusion power plant

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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.

Two established options for possible medium-term implementation of fusion energy production are magnetic confinement - being used in the ITER international project - and laser-based inertial confinement, as used in the French Megajoule laser and in the United States NIF. Inertial confinement fusion (ICF), including heavy-ion inertial fusion (HIF) has been proposed as a possible additional means of implementing a fusion power plant.

Overall principles of an Inertial Fusion Energy (IFE) reactor[edit]

For an easier understanding, it is worth using the analogy of operation between an IFE reactor and a petrol 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.
Further information: An example of a planned IFE plant can be seen in the Z machine article

IFE projects[edit]

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:

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 project that is missing is RF Accelerator HIF as done at Argonne NL and supported by the scientific community as the "conservative way" to go for 37 years but never funded.<>

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[edit]

  1. ^ In the magnetic confinement field, the 2nd phase corresponds to the objectives of ITER, the 3rd to these of its follower DEMO, in 20 to 30 years, and the 4th 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[edit]

External links[edit]

Generalities about IFE[edit]

Inertial fusion experimentation sites[edit]

IFE projects[edit]