Supplemental Material to "Scale-Invariant Nature of Space Charge Oscillations in Electron-Beam Driven Diodes"

The supplemental files include two simulation videos in .gif format. (a) The video shows the temporal evolution of electric potential distribution, which demonstrates the oscillating virtual cathode periodically passing and reflecting electrons. (b) The video shows the temporal evolution of electron velocity phase space with and without gap distance scaled, which visually reveals the scale-invariant natures across the gap.