Magnetic Confinement Fusion
The most famous embodiment of an MCF device is a tokamak–a powerful electromagnetic fields combine with electrical current flowing directly through the plasma to heat and confine the toroidal plasma. The word “tokamak” is a Russian acronym for “toroidal chamber with axial magnetic field”.
Field-Reversed Configuration
FRC devices form self-stable toroidal plasmas similar in form to a smoke ring. A toroidal current is induced inside of a cylindrical plasma, forming a poloidal magnetic field which is reversed with respect to the direction of an externally applied magnetic field. In some FRC devices, such as shown, self-stable toroidal plasmas are then collided at the center of a linear chamber. The resulting toroid can be further stabilized by a variety of methods including neutral beams.
Inertial Confinement Fusion
Dozens to hundreds of extremely powerful pulsed lasers or ion beams focus their energy on a small fusion fuel pellet, compressing it rapidly. The resulting shock wave within the pellet heats up the plasma faster than it can radiate it away.
Magnetized Target Fusion
A hybrid approach to fusion, MTF uses a magnetic field to confine a low-density plasma (like an MCF device), while surrounding the plasma with an (often liquid) metal liner. The metal liner is then heated and compressed using inertial-confinement techniques such as lasers, or pistons. While plasma densities are significantly lower than most ICF machines, the theory is that the longer confinement times and better heat retention will allow MTF devices to produce comparable power levels and will be easier to build.
High speed ions are electrostatically confined in precessing elliptical orbits around a negatively charged cathode. The ion density is increased by the co-confinement of high temperature electrons trapped by an external weak magnetic field perpendicular to the electrostatic field in a “crossed field” configuration similar to a magnetron microwave device. Crossing elliptical paths of ions provide millions of chances of fusion-relevant collisions before the ion loses energy and is moved out of the interaction space as it falls into the cathode and is removed from the chamber.
See The Orbitron