Háskólinn í ReykjavíkReykjavik UniversityÁrnason, Hákon ÖrnTorfason, KristinnManolescu, AndreiValfells, Ágúst2024-02-142024-02-1420240018-93831557-9646https://hdl.handle.net/20.500.11815/4716Molecular dynamics simulations, with full Coulomb interaction, are used to model short-pulse photoemission from a finite area in a microdiode. We demonstrate three emission regimes, source-limited emission, space-charge-limited emission for short pulses, and space-charge-limited emission for the steady state. We show that beam brightness is at a maximum during the transition from the source-limited emission regime to the space-charge-limited emission regime for short pulses. From our simulations, it is apparent that the emitter spot size is an important factor when estimating the critical charge density for short-pulse electron emission and that simple capacitive models may considerably underestimate the total charge emitted.1-8eninfo:eu-repo/semantics/openAccessElectrical and Electronic EngineeringElectronic, Optical and Magnetic MaterialsRafmagnsverkfræðiRafeindaverkfræðiRafsegulfræðiEðlisfræðiinfo:eu-repo/semantics/articleIEEE Transactions on Electron Devices10.1109/TED.2024.3351096