Reversed field pinch current drive with oscillating helical fields

Neoclassical transport in the helical reversed-field pinch.

Test particle evaluation of the diffusion coefficient in a fusion plasma in the reversed-field pinch (RFP) configuration shows distinct similarities with stellarators when the plasma spontaneously evolves towards a helical shape. The almost total absence of superbanana particles at the levels of helical deformation seen in experiment (Bh/B=10%) causes transport to be proportional to collision f...

Use of helical fields to allow a long pulse Reversed Field Pinch

Increased Confinement and b by Inductive Poloidal Current Drive in the Reversed Field Pinch

With the addition of inductive poloidal current drive for current profile control in the Madison Symmetric Torus (MST) reversed field pinch, the magnetic fluctuation amplitude halves, leading to reduced energy and particle transport. A fourto five-fold increase in the energy confinement time to tE , 5 ms with both decreased Ohmic input power and increased stored thermal energy coincides with re...

On the Physics of Improved Confinement During Pulsed Poloidal Current Drive in MST Reversed-Field Pinch

Reduction of core-resonant magnetic fluctuations and improved confinement in the Madison Symmetric Torus reversed-field pinch (MST RFP) have been routinely achieved by applying the surface poloidal electric field. The created inductive poloidal electric field drives current in plasma which leads to the improved confinement. To study the effect we developed a relatively simple 1-D model in cylin...

Mode locking in reversed-field pinch experiments.

The MHD mode trajectory in the Madison Symmetric Torus reversed-field pinch has been found to obey the sine-Gordon equation. Corresponding to experiment, a perturbation analysis predicts the locations of mode locking to be at the vacuum chamber poloidal and/or toroidal gaps. The mode's energy dissipates when it locks, as shown by a decaying spiral phase-plane trajectory. Unlocked modes travel a...