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Electron-optical systems with a cathode lens in telescopic mode
A A Trubitsyn1, E Yu Grachev1, E G Kochergin1
1Ryazan State Radio Engineering University named after V.F. Utkin, Gagarina st. 59/1, Ryazan, 390005, Russia.
Ultramicroscopy
|August 10, 2026
Summary
A new method models cathode lenses, revealing telescopic mode in small cathodes for the first time. This advances electron gun design for high-brightness applications.
Area of Science:
- Physics
- Applied Mathematics
- Electrical Engineering
Background:
- Modeling cathode lenses is crucial for electron optics.
- Existing methods may lack flexibility for arbitrary electrode configurations.
- Understanding telescopic mode is key for optimizing electron beam behavior.
Purpose of the Study:
- To develop a flexible modeling approach for cathode lenses.
- To establish criteria for telescopic mode in cathode lenses.
- To investigate electron guns for high-brightness applications.
Main Methods:
- Developed a boundary element method (BEM) for calculating electric fields on the axis.
- Determined criteria for telescopic mode in idealized and real cathode lenses.
- Optimized numerical modeling algorithms for cathode lenses.
Main Results:
- Successfully modeled cathode lenses with arbitrary electrode configurations.
- Observed telescopic mode for the first time in a lens with a small-diameter cathode.
- Numerically studied a lens with a small-diameter cathode.
Conclusions:
- The developed BEM approach enables effective modeling of complex cathode lenses.
- The findings on telescopic mode offer new insights for electron optics.
- A proposed electron gun design with a thermionic cathode achieves high brightness.
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