Mode-enhanced ion loading in a 100 kV orbitrap

The Orbitron is a compact crossed-field plasma device in development at Avalanche Energy with the purpose of exploring high energy ion confinement above the space charge limit. The successful operation of this device requires efficient capture and confinement of ions from an external source. A variant of the Orbitron was constructed in the form of an electrostatic orbitrap to study and optimize the ion loading process, using a combination of image current, neutron, and magnetic field diagnostics. Appearance of an m = 1 mode coincides with an increase in confinement time by an order of magnitude to 0.8 ms, which enables operating at a steady state density that is 10%–20% of the space charge limit of the device at 100 kV. The development of this mode and its effect on ion confinement are characterized experimentally and with simulations.