What is thermonuclear fusion?
Thermonuclear fusion is a way of achieving nuclear fusion using extremely high temperatures. There are two types of thermonuclear fusion; controlled and uncontrolled.
Controlled thermonuclear fusion occurs in an environment where the energy produced can be harnessed for constructive purposes, while uncontrolled thermonuclear fusion occurs in thermonuclear weapons, such as the hydrogen bomb, or H-bomb.
The key to achieving thermonuclear fusion is confinement; due to the high temperatures, the plasma cannot be in contact with any solid material, and so must be confined in a vacuum
There are three types of confinement used for achieving thermonuclear fusion; gravitational confinement, magnetic confinement, and inertial confinement.
Gravitational confinement is only found in stars, as the mass needed to satisfy the Lawson criterion for fusion is so great, that only stars, the smallest of which are red dwarfs, or, if of sufficient mass, brown dwarfs, which can fuse deuterium and lithium together, can achieve this method of confinement.
Magnetic confinement is used when the electrically charged particles, such as fuel ions, follow the magnetic field lines, and so the fusion fuel can be contained using a strong magnetic field.
Inertial confinement requires a rapid pulse of energy to be applied to a large pellet of fusion fuel, which causes it to implode and heat to a high pressure and temperature.