Electrostatic Orbitron Fusion Device*

The Orbitron is a compact cross-field plasma device that simultaneously confines high energy ions and electrons orbiting around a central cathode. Ions are confined by an electrostatic potential, while electrons are confined with a weak magnetic field. This hybrid approach combines aspects of particle accelerators, orbital ion traps, magnetrons and magnetic mirrors to achieve high plasma densities and long confinement times. The electrostatic ion space-charge limit is mitigated by the confined electrons co-rotating with ions, potentially allowing a high density of ions with energies relevant to ion-ion fusion. The science of the Orbitron plasma device is currently being investigated for its potential as a compact bright neutron source and as a micro fusion reactor. The experimental apparatus and a suite of diagnostics to measure critical parameters such as plasma density, particle energy, and fusion rate for high-energy, non-thermal plasma conditions have been developed. We report on the current state of the experiments as well as the theoretical and computational work investigating the co-confined behavior of quasi-neutral plasmas at very high energies >1 keV.