The APEX experiment for the study of positron-electron ``pair'' plasmas.*

The APEX (A Positron Electron eXperiment) collaboration is working toward achieving simultaneous confinement of large numbers of electrons and positrons in a magnetic dipole trap, with the goal of creating a ``pair'' plasma in the laboratory. Pair plasmas are predicted to exhibit unique properties that differ from the usual electron-ion plasmas and would provide a novel system for studying basic plasma physics. After a brief overview, several recent experiments utilizing the intense, reactor-based cold positron source NEPOMUC to inject positrons into a dipole magnetic field will be presented. These experiments demonstrate several important milestones along the path towards the production of a pair plasma. Current and future activities will also be discussed.