Provided are methods and devices for compression of a spheromak plasma (e.g., deuterium-trirtium (D-T)-derived) in a magnetic well configured within a plasma combustion chamber using an induction coil axially adjacent to the plasma, wherein a moveable member (e.g., piston, cam and follower) drives the induction coil toward the plasma, pushing the plasma via magnetic pressure into the magnetic well and compressing the plasma substantially adiabatically (e.g., coil motion is well below the plasma sound speed). The compression quickly increases both plasma density and temperature past the point of ignition, and after plasma burn, the coil is backed-off to allow the plasma to re-expand, providing for refueling and repetition of the compression cycle. Additionally provided are spaced annular plasma formation electrodes, suitably configured for generating and injecting magnetized plasma into a plasma combustion chamber. Preferably, spaced annular plasma formation electrodes are used in combination with moveable compression members as disclosed herein.
STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH
 The invention was made with government support under Contract No. DE-FG02-06ER84449 from the United States Department of Energy (DOE). The United States government has certain rights in the invention.