Home

Reversed Field Pinch (RFP) configuration and dynamo process

The reversed field pinch (RFP) configuration differs from other schemes of toroidal plasma magnetic confinement since it relies on currents flowing in the plasma for the generation of both poloidal and toroidal components of the magnetic field.
In this way, a highly sheared magnetic configuration can be obtained which is stable with respect to magnetohydrodynamic (MHD) modes at low values of the safety factor and high values of beta.

MHD mode spectrum measured on RFX, showing the amplitudes of modes with m=1 and various n. 

However, while a toroidal current can be efficiently provided by an ohmic transformer, a practical scheme to drive the poloidal current with a similar efficiency is presently lacking.

Experimentally the configuration is realised thanks to a spontaneous dynamo mechanism, driven by global resistive tearing modes resonant on closely spaced magnetic surfaces in the core of the discharge, inside the reversal surface.
These MHD instabilities produce coherent fluctuations in plasma velocities and magnetic fields which induce an electromotive poloidal force which generates and sustains the current distribution against dissipation ("dynamo effect").

 

Safety factor profiles for tokamak and RFP configurations, showing some of the modes that are resonant inside the plasma. For the RFP they are modes with m=1 and n larger than 1/q(0).

MHD mode spectrum measured on RFX, showing the amplitudes of modes with m=1 and various n.

EUROPEAN DOCTORATE IN FUSION

A European Doctoral initiative on Fusion Science and Engineering has been undertaken among the Universities of Padova, Lisbon and Munich aiming at combining two formal participation modalities in the same Doctoral programme course.

Read more

Multimedia

 

banner tesina

 

 

In this section, a combination of different educational and information content is given. Here you can download, for personal use, photo collections, videos, textbooks and brochures on fusion science and technology and on research at Consorzio RFX.

 Read more

Who's online

There are currently 0 users and 2 guests online.