Injection of positrons into a dense electron cloud in a magnetic dipole trap

The creation of an electron space charge in a dipole magnetic trap and the subsequent injection positrons has been experimentally demonstrated. Positrons (5eV) were magnetically guided from their source injected into trapping field generated by permanent magnet (0.6T at poles) using cross E $\times$ B drift, requiring tailored electrostatic fields. cloud is created thermionic emission tungsten filament. maximum potential reaches -42V, which consistent with average density ($4 \pm 2$) $\times 10^{12}$ $\text{m}^{-3}$ Debye length ($2 1$) $\text{cm}$. We demonstrate that presence this does not hamper efficient positron injection. Understanding effects negative on confinement represents important intermediate step towards production confined electron-positron pair plasma.