Techniques of Plasma confinement | Nuclear Fusion

Plasma confinement indicates to the regulation of plasma by various forces at the extreme positions required for thermonuclear fusion reactions.

Method of Plasma confinement

Plasma confinement indicates to the regulation of plasma by various forces at the extreme positions required for thermonuclear fusion reactions. These conditions exist naturally in stars, where they are continued by the force of gravity. In the laboratory, researchers use strong magnetic fields to define plasma. This magnetic confinement strategy may allow them to limit fusion grade plasmas over long periods.

Another imprisonment strategy depends on the inertia of the underlying case. This inertia strategy has been demonstrated on Earth in hydrogen bombings and special features. Inertial imprisonment is an active research area. Laboratories use high-power lasers or electrical discharges to compress hydrogen fuel to very high densities for billions of seconds a second.

Plasma confinement in the magnetic field

The subject of Plasma confinement by magnetic fields is of considerable interest in the theory of controlled thermonuclear fusion. Nuclear fusion is the process by which two light nuclei combine to form a heavier nuclei, the total final mass being slightly less than the total initial mass. The mass difference (Δm) appears as energy (E) according to an Einstein's famous law (E = Δm . c2) where c denotes the speed of light.

Nuclear reaction

D = deuterium, T = tritium. The nuclear fusion reactions are the source of energy in the stars, including the Sun. The confinement of the hot plasma in this situation is provided by the self-gravity of the stars.

Diagram of the D-T reaction
Diagram of the D-T reaction

Various confinement schemes have been suggested and built that use some type of magnetic field configuration. The main experimental efforts for achieving plasma conditions for fusion can be grouped into four categories:-

  1. Open system (magnetic mirror)
  2. Closed system (toruses)
  3. Theta pinch device
  4. Laser-pellet fusion.

Mirror machines are linear devices with an axial magnetic field with magnetic mirrors at the ends to keep particles away from the wall and to reduce the number of particles escaping at each end.

The four principal toroidal systems differ in the way they twist the magnetic field lines. They are the stellarators, the tokamaks, the multipoles and the Astron.

In the theta pinch devices, a plasma current in the azimuthal direction and a longitudinal magnetic field produce a force that compress the cross-sectional area of the plasma.

Since controlled nuclear fusion can provide an almost limitless source of energy, it is certainly one of the most important scientific challenges man faces today, and its achievement will have a huge impact on our civilization.

Fact about plasma confinement

  1. Magnetically confined plasmas have achieved temperatures 10 times hotter than the core of the sun.

  2. The ITER will be the first burning plasma in the world. It aims to generate 500 Mw of fusion power.

  3. NIF is the most energetic laser in the world with 2 megajoules of light energy.

Read also

  1. What is Plasma State of Matter?
  2. Debye Shielding in Plasma
  3. Relation between Phase velocity & Group velocity

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