Characterization of a Duo-emitter Thermionic Diode

The current-voltage (IV) curve and plasma dynam-ics of a vacuum diode, with a low vapor pressure of cesium, are investigated, in which electrons are thermionically emitted from the cathode and cesium ions are emitted from the anode via surface ionization. Two stable branches on the IV-curve were demonstrated experimentally and computationally using particle-in-cell simulations. Contrary to historical claims both branches were found at voltages above and below the electrodes' contact potential. Simulations indicate that ion-neutral scattering could lead to this observed behavior.