https://doi.org/10.1140/epjp/s13360-025-06493-9
Regular Article
An autofocusing system for nuclear microprobes—based on real-time image processing and numerical optimization
1
Department of Physics and Astronomy, Uppsala University, Lägerhyddsvägen 1, 75120, Uppsala, Sweden
2
The Tandem Laboratory, Uppsala University, Lägerhyddsvägen 1, 75121, Uppsala, Sweden
Received:
17
December
2024
Accepted:
28
May
2025
Published online:
25
June
2025
Ion beam focusing for a nuclear microprobe is typically achieved by an operator adjusting the currents supplied to a series of quadrupole magnets, while observing the resulting changes in size and shape of the beam spot via an optical microscope image. This process requires an experienced operator to implement in a reasonable time frame. The present work demonstrates an automated, software-based solution to ion beam focusing. The software determines parameters describing the size and shape of the beam spot in real time, by processing images captured from the microscope. These parameters then provide feedback to a minimisation routine based on the downhill simplex algorithm, which controls the currents supplied to the quadrupole focusing magnets. The minimal beam spot size is achieved in less than three minutes, regardless of the experience of the human operator. The physical microprobe system, on which the software is demonstrated, is not presently capable of achieving spot sizes much below 3 µm, and thus the performance of the software below this limit is still to be determined. Within the limits tested, however, the software demonstrates consistent performance, and greatly enhances the accessibility of the microprobe for less experienced users.
© The Author(s) 2025
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
