Reversed-Field Pinch is a toroidal magnetic confinement scheme. It is an alternative to the Tokamak for building a fusion reactor. It has a low-magnetic-field coil but high-fusion-power density.

The name of the configuration is from toroidal component of the magnetic field. Toroidal component's sign in the outer region of the plasma reverses. The largest Reversed Field Pinch device presently in operation is called the Reversed-Field eXperiment.

Characterics:

Comparable magnetic field plasma intensity

- toroidal component

- poloidal component

Internal field

note: Tokamak's field is toroidal and externally applied.

Advantages:

Natural plasma

Economical

Compact

High power density (minimum energy, stable)

Ignition without the need of auxiliary heating

Internal dynamos

Turbulence driven

Established scalings

Magnetic Topology

The Reversed-Field Pinch works towards a state of "minimum energy".

The magnetic field lines coil loosely around a center torus. They coil outwards. Near the plasma edge, the toroidal magnetic field reverses and the field lines coil in the reverse direction.

Internal fields are bigger than the fields at the magnets.

External links

• Reversed-Field Pinch (RFP) (http://www.iterru.ru/English/AlterPaths/r_f_pinch.htm)
• Self-organized plasmas (http://fusionenergy.lanl.gov/Documents/MTF/seab-siemon%20april%2099.pdf) [PDF]
• Measurement of superthermal electron flow and temperature in a reversed-field pinch experiment by an electrostatic electron energy analyser (http://www.iop.org/EJ/abstract/0741-3335/39/11/010/)

See also: Plasma physics, Nuclear fusion, Stellarator, Tokamak, Magnetic mirror, Magnetohydrodynamics