Electrostatic Orbitron Fusion Reactor: First-Order Power Balance Estimates

In this paper, we explore from a first-principles basis ion and electron Coulomb collisions and momentum transfer in a potential well with an axial magnetic field. This unique configuration of plasma confinement is referred to as an “Orbitron” type configuration. The Orbitron is a “crossed-field” device that attempts to achieve a useful fusion plasma triple product (time, density, energy) by confining high-energy ions electrostatically for long duration orbits around a cathode, as is the case in an Orbitrap [1], while confining electrons in an E×B weak magnetic field, like a Magnetron. The confined electrons mitigates electrostatic ion space-charge density constraints, enabling a high density of ions orbiting with trajectories and energies sufficient for ion-ion fusion. The concept of colliding ion beams for fusion has some similarities to the work of Rostoker, Binderbauer, and Monkhorst [2]. A key difference in the present work is the use of electrostatic orbital ion confinement instead of magnetic ion confinement with a field-reversed configuration FRC device, which significantly changes the ion confinement physics. In addition, electrons in the present work are confined in an E×B field instead of a magnetic FRC. Using the collisional frequencies derived from the Naval Research Laboratory (NRL) Plasma Formulary [3] we applied an analytical first order approach [4] to the Orbitron fusion concept taking into account the unique physics of ions and electrons up and down scattering in a potential well. We found that for D-T fuels, taking into account Coulomb collisions and Bremsstrahlung X-ray losses, a plasma Q > 1 (Power Out / Power) may be possible.