Nanosecond field emitted and photo-field emitted current pulses from ZrC tips

Ganter, R.; Bakker, R.J.; Gough, C.; Paraliev, M.; Pedrozzi, M.; Pimpec, F. Le; Rivkin, L.; Wrulich, A.

doi:10.1016/j.nima.2006.06.054

Cited by 28 publications

(14 citation statements)

References 21 publications

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“…[9][10][11][12][13] Their operation can be affected by the fields from the charges they emit if those fields reduce the extraction field at the emission sites, and such consequences are termed "space charge effects." Such effects can induce undesirable growth in the dimensions of the beam as it propagates, as commonly accounted for in the beam envelope equation; 14 a related metric of beam quality in that equation is called "emittance" and refers to the tendency of a beam to spread as it propagates due to transverse velocity components in the electron distribution function.…”

Section: Introductionmentioning

confidence: 99%

Space charge effects in field emission: Three dimensional theory

Jensen

2010

Journal of Applied Physics

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Field emitters rely on high gradients on microfabricated structures to enable substantial levels of emitted current, which can in turn act to reduce the field at the emission site of a single emitter. An account of that effect is obtained in the following steps: a model of the emitter geometry based on the point charge model that allows for the determination of the apex radius and field enhancement factor for arbitrarily sharp emitter structures is given, followed by an analytical formula for the calculation of total current from such a structure and then by a model of the effect of emitted current in suppressing the field at the emission site. Predictions of the impact of space charge on the emitted current are made and compared to findings of Barbour et al. [Phys. Rev. 92, 45 (1953)] for sharpened structures with varying work function. A discussion is given of the method to combine single tip three-dimensional results with a study of space charge on field emission in one dimension.

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Section: Introductionmentioning

confidence: 99%

Space charge effects in field emission: Three dimensional theory

Jensen

2010

Journal of Applied Physics

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“…Such features, in fact, could improve the photoemission performances of the cathode by the field emission effect [27][28][29] but the formation of large voids and holes on the film surface limits the application of such a device as a cathode. Further studies will be required in the future to improve the morphology of cathodes based on nanostructured Pb thin film.…”

Section: B Pb Film Deposited On Nb Substratementioning

confidence: 99%

Characterisation of Pb thin films prepared by the nanosecond pulsed laser deposition technique for photocathode application

Lorusso¹,

Gontad²,

Broitman³

et al. 2015

Thin Solid Films

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Pb thin films were prepared by the ns pulsed laser deposition technique on Si (100) and polycrystalline Nb substrates for photocathode application. As the photoemission performances of a cathode are strongly affected by its surface characteristics, the Pb films were grown at different substrate temperatures with the aim of modifying the morphology and structure of thin films. Atomic force microscopy and scanning electron microscopy analyses showed a strong morphological change in the deposited films with the substrate temperature, and the formation of spherical grains at higher temperatures with the nucleation of large voids on the film surface. X-ray diffraction measurements showed that a preferred orientation of Pb (111)

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“…The maximum extractable FE current density was reported to be above thermionic and photoemission [1]. FE potentially yields lowest emittance at the source compared to all other electron emission schemes, thanks to the small area of emission [6]. Among FE-based electron sources, different technological approaches have been explored in view of compact FELs, e.g., SwissFEL [7].…”

Section: Introductionmentioning

confidence: 99%

“…Gated FEAs could in principle deliver the required low emittance but the technology suffers from very low charge extraction, cumbersome preparation, and inhomogeneous electron beam profiles. This makes them still inappropriate as reliable electron sources for large scale facilities [2,6,[9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Towards high brightness electron beams from multifilamentaryNb3Snwire photocathode

Ardana-Lamas

Pimpec

Anghel

et al. 2013

Phys. Rev. ST Accel. Beams

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In order to find electron sources of low emittance and high quantum efficiency, single tip cathodes with a microstructured surface are investigated. Emission currents up to 310 A were obtained, by combining a 2 ns, 50 kV accelerating voltage pulse with a 266 nm wavelength, picosecond ( t ¼ 6:2 ps) laser delivering a few J pulse energy. The multifilamentary cylindric Nb 3 Sn tip with a typical diameter of 0.8 mm provides quantum efficiencies up to 0.5%. The microstructured needle has also been tested in a combined diode-rf electron gun with 500 kV, 250 ns pulsed bias voltage as a first step towards reducing emittance-spoiling space-charge forces.

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Nanosecond field emitted and photo-field emitted current pulses from ZrC tips

Cited by 28 publications

References 21 publications

Space charge effects in field emission: Three dimensional theory

Space charge effects in field emission: Three dimensional theory

Characterisation of Pb thin films prepared by the nanosecond pulsed laser deposition technique for photocathode application

Towards high brightness electron beams from multifilamentaryNb3Snwire photocathode

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