The machines with axial constriction (or also called Z-pinch ) currently present one of the methods in the course of investigation for control of the nuclear Fusion.

A small pastille of fuel is placed in the center of a wire cage of Tungstène or Acier. During a strong electric shock, these wire under the effect of heat are transformed into conducting plasma of the current. The component of the whole of the fields of each wire then will compress plasma towards the center of the wire cage and thus will compress the pastille of fuel what will involve the reactions of fusion.

Principle of operation

• Mode of action: by inertial confinement

• Operating process: by impulses

Description of the device

The device of fusion with axial constriction consists of a small capsule of the size approximately of a peppercorn, consisted of fuel of Deutérium and Tritium. This capsule is placed in the center of a cylindrical network composed of wire of Tungstène (approximately 400) by which will pass an impulse of current.

The whole of this device is itself in the center of a cavity making it possible to trap the Rays-X.

Unfolding

An impulse of current of 20 million amp S and one duration of 100 nanoseconds is transmitted by tungsten wire. The very great quantity of energy and the produced heating “vaporize” wire, which transforms them into a plasma. The magnetic field which the current creates violently compresses various individual wire in a tube of plasma in the center of the network.

With the increase in the intensity of the current at the time of the impulse, the magnetic field then will compress the tube of plasma brutally. During this compression, arrived at a limiting stage, called stagnation , plasma stops brutally, and the conversion of the kinetic energy of the electrons and ions of plasma will release from very great quantities of Rays-X.

The Rays-X thus released, from a current radiated power going up to 290 Terawatts, will compress and heat the fuel capsule and will start reactions fusion nuclear.

Storage of energy

In order to obtain and to release in a sufficiently short time the enormous quantity of energy necessary to the operation of the machine for Z-pinch, it is necessary to store energy as a preliminary. This storage is carried out using “swimming pools” filled with water, which play the part of condensers. Energy thus stored could be released in a very short amount of time according to an impulse mode with one extremely short period lower than 100 nanoseconds.

Current limitations

The point of ignition which makes it possible to obtain a sufficiently high number of atomic fusions and to release more energy than it is not necessary any to make function the machine is not at this stage not reached yet. The objective of the next years is to increase the electric output from 20 to 60 million amps.

However, this increase is not without posing problems, because the Rays-X which compress fuels exert also a colossal pressure on the wall of the cavity containing the device. To 60 million amps and a power of 150 Terawatts, this pressure would be about 150 to 500 Gigapascals.

See too

Internal bonds

Modes of containment

• Fusion by inertial confinement

• Fusion by magnetic containment

Others

• nuclear Fusion

• Z machine
• Devices with thermonuclear fusion

External bonds

• nuclear Fusion and axial constriction ('' For science '' 1998)

• National Sandia Laboratories - Z machine
• Sandia' S Z machine exceeds two billion dismantle Kelvin (March 8th, 2006)
• An Inertial-Fusion Z-Pinch Power Plant Concept
• Development path for Z-pinch IFE