Characterization of magnetoplasmadynamic compressors with self-triggering circuits

Erosion-type magnetoplasmadynamic compressors are under consideration as a plasma jet for electrothermal ignition. These are very low impedance devices and the electrical efficiency is greatly degraded when external switchgear is employed. A new triggering scheme is reported where the MPC device acts both as load and switch, which significantly reduces the external electrical loss. The improved electrical efficiency, defined as the percentage of stored electrical energy that is deposited into the plasma during the first half-cycle of the current pulse, is typically η ≈ 12-17%. Electrical, radiative, and blast-wave characteristics such as impulse and shockwave velocity were investigated for very compact MPC's of various designs operating in laboratory air.