Electron field emission is the process by which electrons tunnel from a cathode to an anode, usually through vacuum, by the application of a large voltage bias. Field-emission devices find applications in flat panel displays, electrical circuit breakers, and power diodes. A significant amount of heat can be transferred to the anode from high-energy electrons as they impact the anode surface. This study investigates the heating of a thin, disc-shaped steel anode by field-emitted electrons from a single carbon nanotube. Experiments have demonstrated a temperature rise of more than 11.0 C at the anode center at an energy deposition rate of 16 mW. A finite-difference model is employed to predict the steady-state anode temperature profile resulting from electron field emission, and this profile is compared to that obtained from measurements taken with an infrared camera. The comparison yields information regarding the diameter of the electron beam as it strikes the anode. The paper also discusses significant experimental challenges, which include attaching individual nanotubes on a tungsten needle to withstand the applied electric field and obtaining consistent results during repeated testing.
Electron field emission from a single carbon nanotube: effects of anode location
