Explosive field emission and plasma expansion of carbon nanotube cathodes

Abstract

Articles you may be interested inHigh intensity, plasma-induced electron emission from large area carbon nanotube array cathodes Appl. Phys. Lett. 96, 073109 (2010); 10.1063/1.3313944Field emission properties of plasma treated multiwalled carbon nanotube cathode layers Relationship between field emission property and composition of carbon nanotube paste for large area cold cathode J.High intensity electron emission cathodes based on carbon nanotube films have been successfully fabricated. An investigation of the explosive field emission properties of the carbon nanotube cathode in a double-pulse mode was presented and a high emission current density of 309 A / cm 2 was obtained. The time-and-space resolution of the electron-beam flow from the cathode was investigated. The formation of the cathode plasma layer was proven and the plasma expanded at a velocity of ϳ7.8 cm/ s toward the anode. The formation of cathode plasma has no preferential position and the local enhancement of electron beams is random.

Intense pulsed field emission of carbon nanotube film grown on electroless plated nickel substrate by pyrolysis

“…To the fluctuation in the voltage curves, we think it was caused by the cathode plasma forming in the emission procedure. This opinion can be proved by the results reported in references [12,13]. The difference with their results is that the plasma-induced emission behavior of our sample is not the dominant mechanism.…”

“…The focus on field emission and its applications of most current research work was taken to direct current (DC) emission mode. Recently, the emission characteristics from transplanted CNT Films in intense pulsed emission mode were reported [12,13]. However, the report about the intense pulsed emission characteristics from directly grown CNT films has not been found yet.…”

Plasma-induced field emission study of carbon nanotube cathode

“…The cathode current I k is measured by a sampling resistor inside cathode, and the anode current I a is collected by a Faraday cup in the anode hole. Multiwalled CNTs, synthesized by the thermal chemical vapor deposited process [22], are used as the field emission cathode. The cathode of the 2 MeV LIA injector diode and CNT cathode are shown in Fig.…”

“…The field emission current density only reached A=cm 2 $ mA=cm 2 . Some studies were focused on intense current field emission properties of CNTs for application in linear induction accelerators (LIAs) [15][16][17] and high power microwave tubes [18,19]. The field emission current density can reach hundreds of A=cm 2 .…”

Propagation of individual plasma spots on cathode surface by high-current discharge process

“…These cathodes include carbon fiber cathodes, carbon velvet cathodes with or without CsI coating, and graphite cathodes [4][5][6][7][8]. Since the quite large fields are required for delivering enough energy to electrons to enable their escape of the binding forces into the vacuum, researcher often employ cathodes consisting of long slender structures with a large aspect ratio, of which carbon nanotube cathodes are the most extreme [9]. Carbon fiber cathode is an appropriate choice for generating high-current electron beam, mainly due to its nanosecond timescale turn-on, relatively good vacuum compatibility, and long lifetime [10][11][12].…”