Reversed field pinch

The term reversed field pinch ( RFP) means an appendix to confine fusion plasma. It is a toroidal pinch (English for Crusher ), which uses a unique magnetic field configuration to confine plasma magnetic. It is mainly used for fusion research.

Description

The magnetic field geometry of an RFP is a bit different from the more familiar tokamak. When moved radially outwardly, the toroidal component of the magnetic field is reversed its direction. This property is described reversed field by the name part. This configuration is compared to the tokamak with the same energy density with weaker magnetic fields. A disadvantage of this type of system is that it tends to form larger non- linear effects and turbulence. This makes it the ideal device to investigate non-ideal ( resistive) MHD. RFPs are also used for the study of astrophysical plasma, as there are many similarities.

The largest Reversed Field Pinch plant, which is currently operating, is the " Reversed Field eXperiment ." Other facilities include the Madison Symmetric Torus, EXTRAP T2R in Sweden, and TPE -RX in Japan.

Properties

Unlike the tokamak, which uses much stronger magnetic fields in the toroidal than in the poloidal direction, the field strengths in both directions comparable strong ( although the sign in the toroidal direction changes ) on RFP. In addition, the RFP has a field strength of about one-tenth to half of a comparable Tokamak. In addition, the RFP based on the inducing current in the plasma to the field of magnets reinforce by a dynamo effect.

Benefits

An RFP has several potential advantages. One advantage is that there is no known β limit. β is a parameter which is the average gradient of the magnetic field strength relationship. For practical purposes, β can be regarded as a term of the relative efficiency (this is not exact, but can serve as an estimate ).

  • Natural plasma
  • Economically
  • Compact
  • High energy density ( energy minimum, stable)
  • Ignites without external heating of the plasma

Magnetic topology

RFP operates according to the principle of minimum energy, ie that the potential energy of a charged particle moving along a line are minimal RFP.

The magnetic field lines wrap loosely around the center of a torus. Within the plasma ring, the toroidal magnetic field reverses. The field lines wrap thus continues in the reverse direction.

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