Electron Gun Technologies for High Resolution Electron Microscopes

What Are the Resolution Limits in Electron Microscopes?

The last decade has seen unprecedented strides to everimproving resolutions in electron microscopes. To focus the electrons, these microscopes use round electromagnetic lenses that, unlike glass lenses in optical microscopes, have a positive spherical aberration [1]. Because of this electrons traveling at larger angles away from the incident beam direction are focused more strongly than those t...

High-resolution electron microscopy and electron tomography: resolution versus precision.

The performance of high-resolution electron microscopy and electron tomography is usually discussed in terms of two-point resolution, expressing the possibility of perceiving separately two image points of an object. However, the concept resolution obtains another meaning if one uses prior knowledge about the object and the imaging procedure in the form of a parametric model describing the expe...

High Resolution Backscatter Electron ( Bse ) Imaging of Immunogold with in - Lens and below - the - Lens Field Emission Scanning Electron Microscopes

High resolution backscatter electron (BSE) imaging of colloidal gold with field emission scanning electron microscopy (FESEM) depends upon selection of accelerating voltage, beam current, working distance between specimen and backscatter detector, type of backscatter detector, plus the nature and thickness of the metal coating used to improve conductivity and signal collection. BSE imaging of a...

Proposal for Hollow Cathode Electron Gun for Electron Cooling*

If we put a voltage between the magnetic shunt and two conducting plates perpendicular to the z-axis in a symmetric fashion, we would obtain the same shape of the electric field, because both E and B may be derived as gradient of a potential. We propose to explore this simple physical system, in which E and B are everywhere parallel, to obtain low temperature, magnetically confined electron beams.

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