Observations on Microbunching of Electrons in Laser-Driven Plasma Accelerators and Free-Electron Lasers

Technical Report · Thu Jan 30 04:00:00 EST 2020

DOI:https://doi.org/10.2172/1596020· OSTI ID:1596020

Lumpkin, A. H. ^[1]; Rule, D. W. ^[2]; LaBerge, M. ^[3]; Downer, M. C. ^[3]

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1. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
2. Silver Spring, MD (United States)
3. Univ. of Texas, Austin, TX (United States)

The periodic longitudinal density modulation of relativistic electrons at the resonant wavelength (microbunching) is a fundamental aspect of free-electron lasers (FELs). In one case, microbunching fractions reached 20% at saturation of a self-amplified spontaneous emission (SASE) FEL resulting in gains of 1 million at 530 nm. In that experiment the $$\textit{z}$$-dependent gain of coherent optical transition radiation (COTR) was also measured. In laser-driven plasma accelerators (LPAs), microbunching at visible wavelengths has also been recently reported as evidenced by significant COTR enhancements measured in near-field and far-field images on a single shot for the first time. An analytical model for COTR interferometry (COTRI) addresses both cases. The broadband microbunching observed in the LPA case could act as a seed for a SASE FEL experiment with tunability in principle over the visible regime.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1596020
• Report Number(s): FERMILAB-POSTER--19-111-AD; oai:inspirehep.net:1777869
• Country of Publication: United States
• Language: English

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