Space charge limited current emission for a sharp tip

Journal Article · Fri May 15 00:00:00 EDT 2015 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4919936· OSTI ID:22410286

Zhu, Y. B., E-mail: [e-mail]; Ang, L. K., E-mail: [e-mail] ^[1]

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1. Engineering Product Development, Singapore University of Technology and Design, Singapore 487372 (Singapore)

In this paper, we formulate a self-consistent model to study the space charge limited current emission from a sharp tip in a dc gap. The tip is assumed to have a radius in the order of 10s nanometer. The electrons are emitted from the tip due to field emission process. It is found that the localized current density J at the apex of the tip can be much higher than the classical Child Langmuir law (flat surface). A scaling of J ∝ V{sub g}{sup 3/2}/D{sup m}, where V{sub g} is the gap bias, D is the gap size, and m = 1.1–1.2 (depending on the emission area or radius) is proposed. The effects of non-uniform emission and the spatial dependence of work function are presented.

• OSTI ID: 22410286
• Journal Information: Physics of Plasmas, Vol. 22, Issue 5; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CURRENT DENSITY
ELECTRONS
FIELD EMISSION
SPACE CHARGE
SPACE DEPENDENCE
WORK FUNCTIONS