Design and Simulation of a Multi-Sheet Beam Terahertz Radiation Source Based on Carbon-Nanotube Cold Cathode

Abstract

Carbon nanotube (CNT) cold cathodes are proving to be compelling candidates for miniaturized terahertz (THz) vacuum electronic devices (VEDs) owning to their superior field-emission (FE) characteristics. Here, we report on the development of a multi-sheet beam CNT cold cathode electron optical system with concurrently high beam current and high current density. The microscopic FE characteristics of the CNT film emitter is captured through the development of an empirically derived macroscopic simulation model which is used to provide representative emission performance. Through parametrically optimized macroscale simulations, a five-sheet-beam triode electron gun has been designed, and has been shown to emit up to 95 mA at 3.2 kV. Through careful engineering of the electron gun geometric parameters, a low-voltage compact THz radiation source operating in high-order TM 5 , 1 mode is investigated to improve output power and suppress mode competition. Particle in cell (PIC) simulations show the average output power is 33 W at 0.1 THz, and the beam–wave interaction efficiency is approximately 10%.

Structural Inhomogeneities and Nonlinear Phenomena in Charge Transfer under Cold Field Emission in Individual Closed Carbon Nanotubes

“…CFE from CNTs is also of great practical interest, since high-efficiency cathodes can be created on the basis of CNTs, which open up the possibility of developing a new generation of the microwave and THz components for micro-and nano-solid state and vacuum electronics, including generators, detectors etc. [7,8,[14][15][16][17][18][19] and also the review [20]. The emission of single electrons from individual CNTs makes it possible to create the single-electron devices, which are necessary for quantum technologies [21].…”

Structural Inhomogeneities and Nonlinear Phenomena in Charge Transfer under Cold Field Emission in Individual Closed Carbon Nanotubes

“…CFE from CNTs is also of great practical interest, since high-efficiency cathodes can be created on the basis of CNTs, which open up the possibility of developing a new generation of microwave and THz components for micro-and nano-solid state and vacuum electronics, Micro 2023, 3 942 including generators, detectors, etc. [7,8,[14][15][16][17][18][19][20]. The emission of single electrons from individual CNTs makes it possible to create single-electron devices, which are necessary for quantum technologies [21][22][23].…”

A High-Current-Density Terahertz Electron-Optical System Based on Carbon Nanotube Cold Cathode

“…Conversely, field electron emission cold cathodes support almost instantaneous turn-on, the ability to create ultra-compact designs, tolerance towards small working volumes which relaxes system evacuation requirements, and the ability to operate at near-room-temperature. As a result, field electron emission cold cathodes are coming to the fore as a leading alternative electron emission technology in a new generation of VERS [21][22] variety of electron emission systems, including display devices, microwave sources and X-ray tubes [23][24][25][26][27][28][29].…”