Plasmas in MHD power generation

The plasma found in a magnetohydrodynamic (MHD) generator is discussed. An MHD generator is an expansion engine. It delivers electric rather than mechanical power and there are virtually no upper limits to the temperature it can tolerate, the rapidity of its response, or the power a single unit can be designed to deliver. The behavior of the plasma is uncomplicated compared to that encountered in some other devices, and yet complex, because of the precision with which one needs to know it. The topics included are: generator configurations; electron density; electron mobility; mixture rules; the Hall effect; uniformity; two-temperature plasma; ionization growth at a channel inlet; ionization instability; high enthalpy extraction experiments; segmenting; electrode voltage drop; arcs and electrodes; electrical effects of slag; current control; and waves