Field-reversed configuration

A field-reversed configuration (FRC) is a type of plasma device studied as a means of producing nuclear fusion.

FRCs were a major area of research in the 1960s and into the 1970s, but had problems scaling up into practical fusion triple products (target combinations of density, temperature and confinement time).

[3] The original idea was attributed to the Greek scientist and engineer Nicholas C. Christofilos who developed the concept of E-layers for the Astron fusion reactor.

[12] Private companies now study FRCs for electricity generation, including General Fusion, TAE Technologies, and Helion Energy.

[13] The Electrodeless Lorentz Force Thruster (ELF) developed by MSNW was an attempt to design a space propulsion device.

[14] ELF was a candidate in NASA's NextSTEP advanced electric propulsion program, along with the X-3 Nested-Channel Hall Thruster and VASIMR[15] before MSNW dissolved.

The FRC is also considered for deep space exploration, not only as a possible nuclear energy source, but as means of accelerating a propellant to high levels of specific impulse (Isp) for electrically powered spaceships and fusion rockets, with interest expressed by NASA.

The mainline confinement concepts of tokamak and stellarator do this in a toroidal chamber, which allows a great deal of control over the magnetic configuration, but requires a very complex construction.

The field-reversed configuration offers an alternative in that the field lines are closed, providing good confinement, but the chamber is cylindrical, allowing simpler, easier construction and maintenance.

The high beta makes the FRC attractive as a fusion reactor and well-suited to aneutronic fuels because of the low required magnetic field.

[24][27] In such experiments, as above, a cylindrical coil produces a uniform axial magnetic field and gas is introduced and ionized, creating a background plasma.

Its behavior is not described by classical magnetohydrodynamics, hence there are no Alfvén waves and almost no MHD instabilities despite their theoretical prediction,[citation needed] and it avoids the typical "anomalous transport", i.e. processes in which excess loss of particles or energy occurs.