Electron excursion versus scattering mechanism in a cross-field diode

Summary form only given. The operation of high-power microwave sources in relativistic magnetrons, magnetically insulated transmission lines for pulsed power systems, and Hull thrusters for space propulsion all rely on cross-field diodes. Electron migration from the cathode to the anode should be eliminated due to magnetic insulation, however, many electrons still transit the gap. This leads to the excitation of undesired modes and/or pulse shortening. Previous work has shown that not only does the presence of ions in a crossed-field gap increase the electron excursion toward the anode region¹, but electron scattering and ionization of the background species exacerbate this crossed-field migration.² We have also shown that the farther into the gap the scattering or ionization occurs, the greater the maximum excursion of the scattered or created electron.³ In this work, we will break down the scattering problem further by looking at the scattering due to elastic collisions and excitation events separately. We will use a 1D PIC code⁴ to compare the electron excursions based on scattering mechanism and scattering site. We will further compare the collision type with the expected energy change due to the collision mechanism.