Passive Ballistic Microbunching of Non-Ultrarelativistic Electron Bunches using Electromagnetic Wakefields in Dielectric-Lined Waveguides
- Resource Type
- Working Paper
- Authors
- Lemery, Francois; Piot, Philippe; Amatuni, Gayane; Boonpornprasert, Prach; Chen, Ye Lining; Good, James David; Grigoryan, Bagrat; Gross, Matthias; Krasilnikov, Mikhail; Lishilin, Osip; Loisch, Gregor; Oppelt, Anne; Philipp, Sebastian; Qian, Houjun; Renier, Yves; Stephan, Frank; Zagorodnov, Igor
- Source
- Phys. Rev. Lett. 122, 044801 (2019)
- Subject
- Physics - Accelerator Physics
- Language
Temporally-modulated electron beams have a wide array of applications ranging from the generation of coherently-enhanced electromagnetic radiation to the resonant excitation of electromagnetic wakefields in advanced-accelerator concepts. Likewise producing low-energy ultrashort microbunches could be useful for ultra-fast electron diffraction and new accelerator-based light-source concepts. In this Letter we propose and experimentally demonstrate a passive microbunching technique capable of forming a picosecond bunch train at $\sim 6$~MeV. The method relies on the excitation of electromagnetic wakefields as the beam propagates through a dielectric-lined waveguide. Owing to the non-ultrarelativistic nature of the beam, the induced energy modulation eventually converts into a density modulation as the beam travels in a following free-space drift. The modulated beam is further accelerated to $\sim20$~MeV while preserving the imparted density modulation.