Dynamics of the Active Plasma Experiment North Star Artificial Plasma Jet

Active Plasma Experiment North Star was launched from Poker Flat Research Range, Alaska, on 22 January 1999 at 13:57:03 UT, with two explosive-type generators that produced an artificial aluminum plasma jet. The purpose of this experiment was to study the interaction of the artificial plasma jet with the ambient plasma. The first release occurred at 363 km, and a ∼90% reduction of the geomagnetic field was observed on three separate daughter payloads. The diamagnetic signatures suggest that the plasma cloud was highly localized (i.e., cloud dimensions ∼Al + gyroradius) traveling with a velocity of roughly 25 km/s perpendicular to the geomagnetic field. A hybrid code simulation provided an estimate of the plasma distribution and a qualitative description of the evolution of the plasma cloud. The simulation showed that the plasma cloud polarized and E x B drifted while transferring momentum to the ambient plasma via an Alfvenie disturbance. The model results are in good qualitative agreement with data from the plasma diagnostics payload.