Design and Simulation of Electron Gun for Terahertz Region

An electron gun design optimized for operating in the terahertz (THz) region is proposed, employing a high-brightness electron beam with low emittance. This electron gun is designed to generate a well-focused, high-current electron beam. To improve beam quality and minimize divergence, a periodic cusped magnetic (PCM) system is incorporated to collimate the emitted electron beam. The electron beam dynamics are analyzed, and the collimation efficiency of the PCM system is evaluated to ensure minimal energy spread and maximum beam transport stability. Simulation studies demonstrate that the designed electron gun can generate an electron beam with an energy of 25 keV and a current of 22.5 mA, which is effectively collimated by a 0.2 T PCM system. Analysis of the electron gun with PCM collimation indicates a significant enhancement in beam quality. These results suggest that the proposed electron gun and PCM-based collimation system are highly promising for advancing high-power, frequency-tunable THz sources.