Operation of a Multicell Trap

The multicell Penning-Malmberg trap has been proposed as a way to obtain high-capacity and/or portable antimatter traps.\footnote{Danielson, et. al., {\it Phys. Plasmas} {\bf 13}, 123502 (2006).}$^,$\footnote{Danielson, et al., AIP Conf. Proc. {\bf 1521}, 101 (2013).} A new multicell test-structure is investigated, which has several off-axis cells as well as the capability of studying plasmas with kV space charge potentials. Experiments using test electron plasmas have demonstrated the injection of over 50\% of the plasma into an off-axis trap, and the confinement of plasmas with $2\times10^8$ particles in an off-axis cell for hours using rotating electric fields. Other results to be discussed include the limits of the injection process, stacking plasmas in the off-axis cells, and comparing asymmetry-induced transport in off-axis and on-axis cells. Near-term goals include increasing off-axis injection efficiency, as well as the trapped particle number to $> 10^{10}$ in a single cell. These studies will test further the basic physics of the multicell concept and help refine the design a 21-cell trap for $10^{12}$ positrons.