Three Dimensional Annihilation Imaging of Antiprotons in a Penning Trap

We demonstrate three‐dimensional annihilation imaging of antiprotons trapped in a Penning trap. Exploiting unusual feature of antiparticles, we investigate a previously unexplored regime in particle transport; the proximity of the trap wall. Particle loss on the wall, the final step of radial transport, is observed to be highly non‐uniform, both radially and azimuthally. These observations have considerable implications for the production and detection of antihydrogen atoms.