Electrical characteristics of a MAGPIE coaxial laser discharge system

Initial small scale experiments have demonstrated the ability of relatively weak Lorentz J × B forces to suppress electrothermal instabilities in coaxial laser gas discharges. However, the effective scaling of such plasmas to the much larger volumes required for high-power laser applications has been found to be considerably more difficult than anticipated. In practice, it has been necessary to incorporate a multielement electrode and external ionization to achieve acceptable performance. This paper describes the design features of such a large volume Magpie (magnetically stabilized, pulse ionized, electrically excited) discharge system and presents the electrical and thermal characteristics of the resulting magnetically stabilized radial plasma. These are discussed in relation to eventual high-power CO2 laser applications.