Development of a positron multicell trap.

There are numerous potential applications of high-capacity and/or portable antimatter traps. Previously, we proposed the design for a high-capacity, multicell Penning-Malmberg (PM) trap for positrons \footnote{ C. M. Surko and R. G. Greaves, Rad. Phys. and Chem. {\bf 68}, 419 (2003); and Phys. Plasmas {\bf 11}, 2333 (2004)}. Here, we discuss electron experiments designed to test the limits of confinement in a single PM cell. Specific issues include operation with potentials $\ge$ 1 kV and trapping and storage of $10^{10}$ particles at densities $\ge 10^{10} \ {\rm cm}^{-3}$. We are also exploring methods for the dynamic manipulation and control of trapped plasmas, and methods to access off-magnetic-axis cells. The results of these studies will be used to finalize the design of a 95-cell trap for $N \ge 1 \times 10^{12}$ positrons. Possible extensions of this design, and expected limits on positron accumulation, will also be discussed.