LINAC2026 - 33rd Linear Accelerator Conference

Using Stretching-Modulation-Compression Effect to Generate Femtosecond MeV Electron Bunches

Not scheduled

2h

Daejeon Convention Center

Poster Presentation MC1.A01: Beam Dynamics, beam simulations, beam transport Poster Session

Speaker

Qiao Luo (Huazhong University of Science and Technology)

Description

We propose a scheme for generating femtosecond to sub-femtosecond ultrafast electron bunches by combining undulator technology with terahertz (THz) modulation. A theoretical model has been developed to describe the transport dynamics of relativistic electrons interacting with THz modulation fields and longitudinal space charge effects within the bunch. The proposed scheme successfully produces isolated ultrafast electron bunches with kinetic energy ~3 MeV, bunch length ~6 fs (rms), and charge up to 0.1 pC, as well as microbunch trains with ~800 as length, ~2 fC charge, and tunable ~200 um spacing. By adjusting upstream and downstream longitudinal dispersion, the bunch structure and microbunch length can be effectively controlled. We provide scaling relations for key parameters with respect to initial bunch charge and analyze the influence of various physical quantities on final bunch length and arrival time. This theoretical model and scheme may offer valuable insights for generating few-femtosecond or attosecond electron bunches in accelerator-based ultrafast facilities.

Funding Agency

This work is supported by the Fundamental Research Funds for the Central Universities (HUST) under Project No. 2021GCRC006 and National Natural Science Foundation of China under Project No. 12275094.