Single mineral particle makes an electron point source

Salançon, Evelyne; Daineche, Rachid; Grauby, Olivier; Morin, Roger

doi:10.1116/1.4916237

Cited by 6 publications

(10 citation statements)

References 32 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Note that the Fowler-Nordheim curve for these intensity measurements plotted in Fig.4c confirms the process involved here as field electron emission. For the highest intensities 1 µA), the plot changes and shows a level of saturation previously observed for this kind of source 35 . Field emission is observed for more than 10 orders of magnitude.…”

Section: B Measurements Over a Large Voltage Rangesupporting

confidence: 53%

See 1 more Smart Citation

From measuring electron charge to exploring particle-wave duality: A new didactic experimental approach

Salançon

Degiovanni

Lapena

et al. 2019

American Journal of Physics

Self Cite

View full text Add to dashboard Cite

This paper points out the strong didactic potential of an experiment originally intended for electron source research. Using a dual stage micro-channel plate in a low-energy electron point projection microscope, electrons are spatially detected one by one. Field electron emission affords wide-ranging intensity, enabling the electron charge to be determined by comparing counting and analog measurements. The same setup is used to illustrate the buildup of an interference pattern from separate low-energy electron detection, thereby enabling the Planck constant to be determined. Both granular and continuous signals are directly observable in this educational approach.

show abstract

Section: B Measurements Over a Large Voltage Rangesupporting

confidence: 53%

“…Here, the electron source relies on a field emission process. The source consists of a celadonite insulating crystal placed at the apex of a carbon wire 35 . The intensity is measured using a picoammeter (Keithley 485) floating between the power supply and the source.…”

Section: Methodsmentioning

confidence: 99%

From measuring electron charge to exploring particle-wave duality: A new didactic experimental approach

Salançon

Degiovanni

Lapena

et al. 2019

American Journal of Physics

Self Cite

View full text Add to dashboard Cite

show abstract

“…Yet the applied electric field is only some V/µm. Since field emission requires an electric field of some V/nm this means that there is an electric field enhancement at the metal/insulator interface [15].…”

Section: -Experimental Setupmentioning

confidence: 99%

“…For ultra-sharp tips, the source-to-object distance can be decreased down to sub-micrometer level while retaining point-source behavior and large enough magnifications, without running the risk of the tip crashing into the object. We recently introduced an electron source [13,14,15] based on emissions from a single insulator crystal of celadonite deposited at the apex of a 10µm-diameter carbon fiber. In terms of the wave, this provides a point-source although, physically-speaking, the source is wide.…”

mentioning

confidence: 99%

A low-energy electron point-source projection microscope not using a sharp metal tip performs well in long-range imaging

et al. 2019

Self Cite

View full text Add to dashboard Cite

A low-energy electron point-source projection microscope that uses a metal/insulator structure as source instead of a sharp metal needle is presented. By combining this source with an electron optical lens and a high spatial resolution image detector, performances comparable to those of a normal electron projection microscope are easily accessible and presented here. The accessible electron energy range extends from 100eV to 1000eV. In the example presented here, instead of the usual near-field source-object distance, long-range imaging at a distance of about 600µm is achieved. 1-Introduction The normal low-energy electron point-source projection microscope [1,2,3,4] is a lensless system where an electron point source illuminates a perforated object, and the "physical shadow" of the object is recorded on a more distant fluorescent screen. The so-called physical shadow corresponds to the interference between the reference wave that comes directly from the source and the object wave that results from object scattering. This Fresnel interference pattern is an electronic hologram of the object. Numerical reconstruction yields an image of the object in its position during the recording [5,6,7].The projection microscope is known to reach a magnification of about 10 5 with an experimental spatial resolution of about 1nm [8,9,10]. These

show abstract

“…The resulting source is a coaxial point-source allowing good alignment between the source, the object and the electron optical system [10]. Because its 10µm diameter is still wider than ultrasharp tips the source-to-object distance is limited to some tens of micrometers.…”

Section: Introductionmentioning

confidence: 99%

Preparing a Celadonite Electron Source and Estimating Its Brightness

Salançon

Degiovanni

Lapena

et al. 2019

JoVE

Self Cite

View full text Add to dashboard Cite

The electron celadonite source described in this article performs well in a low-energy electron point-source projection microscope in long-range imaging. It presents major advantages compared to sharp metal tips. Its robustness affords a lifetime of months and it can be used under relatively high pressure. The celadonite crystal is deposited at the apex of a carbon fiber, maintained itself in a coaxial structure ensuring a spherical beam shape and easy mechanical positioning to align the source, the object and the electron-optical system axis. There is a single crystal deposition via generation of celadonite-containing water droplets with a micropipette. Scanning electron microscopy observation can be performed to verify the deposition. However, this adds steps and therefore increases the risk of damaging the source. Thus, after preparation, the source is usually inserted directly under vacuum in the projection microscope. A first high voltage supply provides the kick-off needed to start the electron emission. The field emission process involved is then measured: it has already been observed for dozens of electron sources prepared in this way. The brightness is underestimated through an overestimation of source size, intensity at one energy and cone angle measured in a projection system.

show abstract

Single mineral particle makes an electron point source

Cited by 6 publications

References 32 publications

From measuring electron charge to exploring particle-wave duality: A new didactic experimental approach

From measuring electron charge to exploring particle-wave duality: A new didactic experimental approach

A low-energy electron point-source projection microscope not using a sharp metal tip performs well in long-range imaging

Preparing a Celadonite Electron Source and Estimating Its Brightness

Contact Info

Product

Resources

About