Emission characteristics of planar field electron emitters containing carbon nanotubes operating in the high current density mode

Izrael’yants, K. R.; Musatov, A. L.; Ormont, A. B.; Chirkova, E. G.; Kukovitsky, E. F.

doi:10.1016/j.carbon.2010.01.033

Cited by 7 publications

(2 citation statements)

References 25 publications

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“…To further investigate the emission stability of SiO 2 -wrapped CNTs, emission stability tests are carried out on free-standing and SiO 2 wrapped CNTs, as shown in figure 9. The stability test is carried out over a duration of 4000 s, similar to the reported studies [22,47]. At the beginning of this emission stability test, the applied electric field on free-standing and SiO 2 -wrapped CNTs is tuned to 5.5 and 8.5 V μm −1 , respectively, to obtain similar ∼22 mA cm −2 current density for both CNTs as obtained in the earlier FE measurements (figure 8).…”

Section: Electric Field Simulation Of Freestanding and Sio 2 -Wrapped...mentioning

confidence: 80%

Field emission properties of SiO₂-wrapped CNT field emitter

Lim

Xia

et al. 2017

Nanotechnology

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Carbon nanotubes (CNTs) exhibit unstable field emission (FE) behavior with low reliability due to uneven heights of as-grown CNTs. It has been reported that a mechanically polished SiO-wrapped CNT field emitter gives consistent FE performance due to its uniform CNT heights. However, there are still a lack of studies on the comparison between the FE properties of freestanding and SiO-wrapped CNTs. In this study, we have performed a comparative study on the FE properties of freestanding and SiO-wrapped CNT field emitters. From the FE measurements, freestanding CNT field emitter requires lower applied voltage of 5.5 V μm to achieve FE current density of 22 mA cm; whereas SiO-wrapped field emitter requires 8.5 V μm to achieve the same current density. This can be attributed to the lower CNT tip electric field of CNTs embedded in SiO, as obtained from the electric field simulation. Nevertheless, SiO-wrapped CNTs show higher consistency in FE current than freestanding CNTs. Under repeated FE measurement, SiO-wrapped CNT field emitter achieves consistent FE behavior from the 1st voltage sweep, whereas freestanding field emitter only achieved consistent FE performance after 3rd voltage sweep. At the same time, SiO-wrapped CNTs exhibit better emission stability than freestanding CNTs over 4000 s continuous emission.

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Section: Electric Field Simulation Of Freestanding and Sio 2 -Wrapped...mentioning

confidence: 80%

Field emission properties of SiO₂-wrapped CNT field emitter

Lim

Xia

et al. 2017

Nanotechnology

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“…7 Experimental measurements of ␤ in different CNT array configurations have shown orders of magnitude variations 100Ͻ ␤ Ͻ 20 000 from one array to another [16][17][18] 7 Experimental measurements of ␤ in different CNT array configurations have shown orders of magnitude variations 100Ͻ ␤ Ͻ 20 000 from one array to another [16][17][18] …”

Section: B Acceleration Regionmentioning

confidence: 99%

Field emission cathode with electron optics for use in Hall thrusters

Kronhaus¹,

Kapulkin²,

Guelman³

2010

Journal of Applied Physics

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Investigation of a microtriode with a planar field emitter-extractor source fabricated by direct-write nanolithography using electron beam induced deposition A compact electron energy analyzer for measuring field emission energy distributions Rev. Sci. Instrum. 70, 3299 (1999); 10.1063/1.1149907 Electron field emission from a patterned diamondlike carbon flat cathode This paper is devoted to the development and numerical modeling of a field emission cathode for low power Hall thrusters ͑100-300 W͒. Generally, Hall thrusters use hollow cathodes, which require a relatively large mass flow rate of xenon-gas to operate. For lower emission currents the cathode gas consumption is still substantial, which contributes to the drop in efficiency when operating a Hall thruster in a low power regime. Conventional field emission cathodes, which are considered as an alternative, do not provide the required low power consumption with an acceptable lifetime. In order to increase the efficiency of the field emission cathode while retaining an acceptable lifetime, an acceleration-deceleration electron optics is proposed. This system is used for the extraction of electrons from carbon nanotubes and the formation of the electron beam. Numerical modeling of the processes in the proposed cathode was carried out using a particle-in-cell approach. It has been shown that ͑1͒ it is possible to provide adequate transmission of the electron beam at the required deceleration voltage; ͑2͒ injecting xenon-gas at the outlet of the cathode for the creation of a "plasma-bridge" between the cathode and ion beam does not lead to significant population of ions near the emitter surface. A cathode with electron current of 1 A was modeled using a particle-in-cell simulation. The cathode requires only ϳ15 W of power and 0.11 mg/s of xenon mass flow rate. For the given current, these parameters are quite reasonable.

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