Thermionic Energy Converter (2D)

Heat a metal surface hot enough and electrons boil off it — the Richardson-Dushman effect. Face that hot emitter across a narrow vacuum gap at a cooler collector and those electrons condense into a current with no turbine, no fluid, and no moving parts. This 2D top-down cross-section renders the emitter, the collector and the electron stream crossing the gap, driven by the actual Richardson-Dushman emission equation and the Child-Langmuir space-charge law that caps how much of that current a given gap width can actually carry. Four controls — emitter and collector temperature, emitter work function, and vacuum gap — feed live readouts for current density, barrier voltage, output power density and efficiency relative to the Carnot limit, and the electron stream's own crossing rate and spacing visibly change the moment the device crosses from temperature-limited into space-charge-limited operation.