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Simulation Study of the Field Emission Characteristics of a Groove-Filled Emitter in a CNT-based X-ray Source
New Phys.: Sae Mulli 2019; 69: 240~246
Published online March 29, 2019;
© 2019 New Physics: Sae Mulli.

Seong-Ryong RYU, Tae Dong LEE*

Department of Optical Engineering, Kumoh National Institute of Technology, Gumi 39177, Korea
Correspondence to:
Received December 13, 2018; Revised January 17, 2019; Accepted January 25, 2019.
cc This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
In a CNT-based X-ray tube, minimizing the leakage current to the gate is crucial and having a uniform current emission across the emitter area is desirable. To find potentially effective structures, we performed electron optics simulations using a model in which the area of the CNT emitter was smaller than the gate opening. On the directly deposited emitter, the current was concentrated at the stepped edge and the most of the current became gate leakage. In contrast, the groove-filled emitter showed no gate leakage current and has a more uniform electric field and current distribution. The current distribution was more uniform for a narrower emitter and for a larger gate-emitter distance. The total emission current increased as the emitter width was decreased and the gate height was increased.
PACS numbers: 79.70.+q, 85.35.Kt, 61.48.De
Keywords: CNT X-ray source, Field emission, Simulation

March 2019, 69 (3)
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