Attosecond electron bunch compression scheme based on transverse gradient undulator

Liu Yinghan; Gu Duan

doi:10.11884/HPLPB202638.250413

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Article Navigation > High Power Laser and Particle Beams > 2026 > Accepted Manuscript

Liu Yinghan, Gu Duan. Attosecond electron bunch compression scheme based on transverse gradient undulator[J]. High Power Laser and Particle Beams. doi: 10.11884/HPLPB202638.250413

Citation:

Liu Yinghan, Gu Duan. Attosecond electron bunch compression scheme based on transverse gradient undulator[J]. High Power Laser and Particle Beams. doi: 10.11884/HPLPB202638.250413

Liu Yinghan, Gu Duan. Attosecond electron bunch compression scheme based on transverse gradient undulator[J]. High Power Laser and Particle Beams. doi: 10.11884/HPLPB202638.250413

Citation:

Liu Yinghan, Gu Duan. Attosecond electron bunch compression scheme based on transverse gradient undulator[J]. High Power Laser and Particle Beams. doi: 10.11884/HPLPB202638.250413

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Attosecond electron bunch compression scheme based on transverse gradient undulator

doi: 10.11884/HPLPB202638.250413

Liu Yinghan^{1, 3
,},
Gu Duan^{2
,
,}

1.
Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
2.
Shanghai Advance Research Institute, Chinese Academy of Sciences, Shanghai 201210, China
3.
University of Chinese Academy of Sciences, Beijing 100049, China

Funds: Supported by Shanghai Action Plan for Science, Technology and Innovation (24JD1402800), National Key Research and Development Program of China (2024YFA1612201), National Natural Science Foundation of China (12575162)

More Information

Author Bio:
Liu Yinghan, liuyinghan@sinap.ac.cn
Corresponding author: Gu Duan, gud@sari.ac.cn
Received Date: 2025-11-19
Accepted Date: 2026-04-13
Rev Recd Date: 2026-04-15

Available Online: 2026-05-06

Abstract

Abstract

Background
Sub-femtosecond electron beams offer enormous promise for furthering ultrafast research, including ultrafast electron diffraction and free-electron lasers. However, traditional compression techniques are essentially constrained by slice energy spread and cannot stably produce sub-femtosecond electron beams.
Purpose
This work proposes a unique compression strategy based on a Transverse Gradient Undulator (TGU). The slice energy spread is actively reduced by taking advantage of the link between transverse position and energy modulation in the TGU, hence breaking the compression limit.
Methods
Theoretical proof has been provided of the suppression effect of TGU on slice energy spread, with confirmation of the relevant parameters influencing this effect. A complete compression beamline has been designed, and numerical simulations conducted.
Results
Numerical simulations show that the proposed approach may compress the electron beam from 50 fs to less than 1 fs, with a compression factor over 52.09. Although phase jitter in the electron gun’s electric field affects the final compression pulse length, adjusting the modulation laser parameters of the TGU can effectively improve the compression results.
Conclusions
This study confirms that the TGU with flexible tunability and suppression of slice energy dispersion can be explored to be applied in ultrafast science research.
- attosecond electron bunch,
- bunch compression,
- transverse gradient undulator,
- slice energy spread,
- ultrafast electron diffraction

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References(31)

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