multipurpose bright electron source

Multipurpose bright electron source

The current electron sources in a Transmission Electron Microscope face limitations regarding the quality of the emitted beam and the possibility to manipulate the beam, which reduce the performance of the TEM.

The aim of WP3 is to design and develop an advanced electron source that overcomes these limitations and allows the exploration of novel concepts in electron microscopy. This source will seamlessly integrate with various microscopy setups as well as other instruments. The enhancement of the performance characteristics of the electron source, such as brightness, emittance, and flexibility, will facilitate significantly improved and more versatile imaging and spectroscopy.

This innovative electron source will make advanced microscopy more accessible and effective for researchers, without requiring costly upgrades or complex modifications.


To design an electron emission gun with a superimposed magnetic field

An innovative magnetic-field emission gun (MFEG) will be developed. The use of a magnetic field in conjunction with a cold field emission gun reduces the distance to the optical axis of the trajectories of emitted electrons.

This will significantly mitigate spherical aberration and enhance the optical performance of microscopes in various ways, e.g. spectroscopy.


To develop a compact aberration corrector for the electron emission gun

A compact aberration correction device will be designed based on the quadrupole-octupole principle. The quadrupole consists of four electrostatic poles, which focus and shape the electron beam, while also producing octupole stray fields induced by round electrodes placed in front and behind the quadrupole.

By adjusting the strength and configuration of the electrode assembly, these elements manipulate the trajectories of electrons and effectively compensate for aberrations in the electron beam. This electrostatic self-aligned corrector provides substantial improvement over other corrector designs in terms of compactness, number of adjustable elements, and hence compatibility with existing gun technology.


To design a set of devices for temporal modulation of the electron beam

Innovative devices to modulate the electron beam within the time domain will be developed, comprising precision-engineered structures such as lenses, cavities, apertures and magnetic assemblies. These components control the trajectory and timing of electrons for sub-nanosecond temporal resolution.

Pushing temporal boundaries, this modulation enables advanced applications beyond current sources, including studying dynamic material and device properties such as magnetic memory switching, or detecting critical events like cell division.


To develop a software that simulates the electron optics

An advanced computation framework will be developed to simulate the behavior of fast charged particles, such as electrons in a TEM. This framework will facilitate the automatic optimization of key design parameters, like the shape, size and distance of lenses and multipoles of a TEM. Optimizing these parameters will assist in crafting innovative electron optics which are not currently available commercially.

This advancement has broad applications, offering detailed insights into cutting-edge research, material science, biological processes, diagnostic capabilities and technological innovations.

Axel Lubk

WP3 Team Leader