Practical limits on positron accumulation and the creation of electron-positron plasmas

The tasks of accumulating large numbers of positrons, creating high-density positron plasmas, and confining electron-positron plasmas present a number of technical challenges. Some practical considerations and limitations of common confinement schemes are discussed. A novel design for a multi-cell Penning-Malmberg trap is proposed for the accumulation of large numbers of positrons (e.g., > 10(12) and T similar to 0.5 eV). A method is described to create a low-density, electron-positron plasma (e.g., n similar to 10(7) cm(-3)) for basic plasma physics studies that uses a combination of radio-frequency and magnetic confinement. The possibilities for confinement of a hot (e.g., T > 10 keV) electron-positron plasma in a magnetic mirror are also discussed.