Recent Advances in Electric Arc Plasma Generation Technology

A state-of-the-art review is presented vith particular attention to arc- heated wind tunnels and space engines. The material is divided into sections on applications, design and operating characteristics, and factors affecting performance. The applications discussed are chemical synthesis, refractory processing, high-temperature research, reentry simulation, and space propulsion. The recent types of plasma generators nearly all have rotational symmetry with coaxial electrodes with an annular gap for the arc and through which the gas flows. The three principal configurations in use are cylindrical, toroidal, and constricted. The voltage-current characteristics, calibration procedures, operating limits, contamination, a-c operation, and r-f heating are also discussed. The factors affecting plasma generator performance are discussed as convective and radiative heat losses, electrode processes, arc-column behavior, and magnetic -field effects.