Reduction of field emission dark current for high-field gradient electron gun by using a molybdenum cathode and titanium anode

Furuta, F.; Nakanishi, Toru; Okumi, Shoji; Gotou, T.; Yamamoto, Manabu; Miyamoto, Masashi; Kuwahara, Makoto; Yamamoto, Norimasa; Naniwa, K.; Yasui, K.; Matsumoto, Hiroshi; Yoshioka, M.; Togawa, Kazuaki

doi:10.1016/j.nima.2004.08.131

Cited by 41 publications

(25 citation statements)

References 10 publications

(8 reference statements)

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“…This enhancement factor can be related to the detailed shape and/or the rugosity of the surface, and there is experimental evidence that smoothing the surface decreases emission. Typically, b values of several hundreds have been obtained for an unpolished stainless steel 24 or copper 25 surfaces, whereas b of several tens have been measured for titanium, molybdenium, 26 and niobium, 27 for rugosities of the Published by AIP Publishing. 120, 085105-1 order of ten nanometers or more.…”

Section: Introductionmentioning

confidence: 99%

Static electric field enhancement in nanoscale structures

Lepetit

Lemoine

Márquez-Mijares

2016

Journal of Applied Physics

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We study the effect of local atomic-and nano-scale protrusions on field emission and, in particular, on the local field enhancement which plays a key role as known from the Fowler-Nordheim model of electronic emission. We study atomic size defects which consist of right angle steps forming an infinite length staircase on a tungsten surface. This structure is embedded in a 1 GV/m ambient electrostatic field. We perform calculations based upon density functional theory in order to characterize the total and induced electronic densities as well as the local electrostatic fields taking into account the detailed atomic structure of the metal. We show how the results must be processed to become comparable with those of a simple homogeneous tungsten sheet electrostatic model. We also describe an innovative procedure to extrapolate our results to nanoscale defects of larger sizes, which relies on the microscopic findings to guide, tune, and improve the homogeneous metal model, thus gaining predictive power. Furthermore, we evidence analytical power laws for the field enhancement characterization. The main physics-wise outcome of this analysis is that limited field enhancement is to be expected from atomic-and nano-scale defects. Published by AIP Publishing.

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Section: Introductionmentioning

confidence: 99%

Static electric field enhancement in nanoscale structures

Lepetit

Lemoine

Márquez-Mijares

2016

Journal of Applied Physics

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“…Before presenting results obtained with our electrodes, it is of importance to bear in mind results obtained by Furuta et al [26,27] and Diamond [25,28]. According to Furuta's publication, the design of their electrodes are equivalent to ours.…”

Section: Resultsmentioning

confidence: 88%

“…Once the electrodes are installed under vacuum, our intention is to use plasma glow discharge (PGD), known to be an efficient way of cleaning surfaces and removing the contamination which can promote field emission. We do not think the exceptional surface preparation achieved by the procedure in [26] will survive an aggressive PGD.…”

Section: Electrode Preparation and Testingmentioning

confidence: 93%

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Field emission dark current of technical metallic electrodes

Pimpec

Ganter

Betemps

2007

Nuclear Instruments and Methods in Physics Research Section A:

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In the framework of the Low Emittance Gun (LEG) project, high gradient acceleration of a low emittance electron beam will be necessary. In order to achieve this acceleration, a -500 kV, 250 ns FWHM, pulse will be applied between two electrodes. Those electrodes should sustain the pulsed field without arcing, must not outgas and must not emit electrons. Ion back bombardment, and dark current will be damaging to the electron source as well as for the low emittance beam. Electrodes of commercially available OFE copper, aluminium, stainless steel, titanium and molybdenum were tested, following different procedures including plasma glow discharge cleaning.

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“…However, even a modest increase in operating voltage will greatly improve the capture efficiency of the injector system. Several methods have been successfully used to decrease or at least limit the dark current, including increasing the pumping speed near the cathode [4], careful cleaning of the electrode material(s), optimizing the shape of the cathode electrode [5], and use of Mo and Ti for the cathode and anode electrode materials respectively [6]. In addition, a dramatic decrease in dark current has been reported for implantation of stainless-steel with N 2 ions [7].…”

Section: Polarized Gun Developmentmentioning

confidence: 99%

The ILC Polarized Electron Source

Brachmann

Clendenin

Garwin

et al.

Proceedings of the 2005 Particle Accelerator Conference

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The SLC polarized electron source (PES) can meet the expected requirements of the International Linear Collider (ILC) for polarization, charge and lifetime. However, experience with newer and successful PES designs at JLAB, Mainz, Nagoya and elsewhere can be incorporated into a first-generation ILC source that will emphasize reliability and stability without compromising the photocathode performance. The long pulse train for the ILC may introduce new challenges for the PES, and in addition more reliable and stable operation of the PES may be achievable if appropriate R&D is carried out for higher voltage operation and for a simpler load-lock system. The outline of the R&D program currently taking shape at SLAC and elsewhere is discussed. The principal components of the proposed ILC PES, including the laser system necessary for operational tests, are described.

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Reduction of field emission dark current for high-field gradient electron gun by using a molybdenum cathode and titanium anode

Cited by 41 publications

References 10 publications

Static electric field enhancement in nanoscale structures

Static electric field enhancement in nanoscale structures

Field emission dark current of technical metallic electrodes

The ILC Polarized Electron Source

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