Onset of space charge limited current for field emission from a single sharp tip
Ang, Ricky Lay Kee
Date of Issue2012
School of Electrical and Electronic Engineering
A protrusive model of the Child-Langmuir (CL) law is proposed for non-uniform electron field emission from a sharp tip of either Lorentzian or hyperboloid shape. The model is expressed as Jc = μ×J1D at large electric field higher than a critical value Ec, and J1D is the classical one-dimensional CL law. It is found that the enhancement μ over the 1D CL law depends only on the calculated field enhancement factor (β) of the emitter and is independent of the work function and gap spacing. In particular, μ increases with β and it converges to a constant at β≫ 1 for a very sharp tip with small emission area.
DRNTU::Engineering::Electrical and electronic engineering
Physics of plasmas
© 2012 American Institute of Physics. This paper was published in Physics of Plasmas and is made available as an electronic reprint (preprint) with permission of American Institute of Physics. The paper can be found at the following official DOI: [http://dx.doi.org/10.1063/1.3695090]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.