How does the Hall effect affect a plasma MHD generator?

In a plasma magnetohydrodynamic (MHD) generator, the Hall effect occurs because electrons in the plasma possess significantly higher mobility than ions. When an electric load current flows across the generator channel, these electrons experience a force directed along the channel axis.1

This phenomenon causes the electric current to flow at an angle across the channel rather than directly between the electrodes. Consequently, an additional electric field, known as the Hall field, is established along the channel axis. To manage this effect, engineers must either design electrode walls capable of supporting this axial field or utilize the Hall field itself to drive current through an external circuit.1

Several configurations have been developed to accommodate this behavior:

• Faraday generator: Uses segmented, insulated electrode walls to support the axial electric field, allowing power to be extracted through a series of loads.1
• Hall generator: Short-circuits the Faraday field across channel sectors and connects them in series, enabling the use of a single electric load.1
• Diagonal generator: Employs staggered electrodes that match the diagonal equipotentials of the channel, also permitting a single load.1
• Disk generator: Features radial load current flow with circular Faraday currents, extracting the Hall output between the center and the periphery.1