Single-Shot Diagnostics of Microbunched Electrons in Laser-Driven Plasma Accelerators and Free-Electron Lasers

Conference · Sun Sep 01 04:00:00 EDT 2019

OSTI ID:1571790

Lumpkin, A. H. ^[1]; Rule, D. W.

---

1. Fermilab

aThe need for single-shot diagnostics of the periodic longitudinal density modulation of relativistic electrons at the resonant wavelength (microbunching) in a free-electron laser (FEL) or at broadband visible wavelengths as in a laser-driven plasma accelerator (LPA) has been reaffirmed. In the self-amplified spontaneous emission (SASE) FEL case, statistical fluctuations in the microbunching occur in the startup- from-noise process. In the LPA, the plasma itself is chaotic and varies shot to shot. Fortunately, we have shown that coherent optical transition radiation (COTR) techniques, can assess beam size, divergence, spectral evolution, and z-dependent gain (100,000) of microbunched electrons in a past SASE FEL experiment at 530 nm*. Recently, the application to LPAs has been demonstrated with single-shot near-field (NF) and far-field (FF) COTR imaging done at the exit of an LPA for the first time**. In this case few-micron beam sizes and extensive fringes due to su b-mrad divergences were measured based on point-spread-function effects and an analytical model for COTR interferometry (COTRI), respectively. A new COTR-based diagnostics application to pre-bunched electron beams formed by co-propagating a laser pulse and the electron pulse in a short undulator (modulator) is also described.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1571790
• Report Number(s): FERMILAB-POSTER-19-115-AD; oai:inspirehep.net:1761031
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS