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arXiv · 1907.05078

Interferometric optical signature of electron microbunching in laser-driven plasma accelerators

A. H. Lumpkin·M. LaBerge·D. W. Rule·R. Zgadzaj·A. Hannasch·O. Zarini·B. Bowers·A. Irman·J. P. Couperus-Cabadag·A. Debus·A. Köhler·U. Schramm·M. C. Downer
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Abstract

We report observations of coherent optical transition radiation interferometry (COTRI) patterns generated by microbunched ~200-MeV electrons as they emerge from a laser-plasma accelerator. The divergence of the microbunched portion of electrons, deduced by comparison to an analytical COTRI model, is ~6x smaller than the ~3 mrad ensemble beam divergence, while the radius of the microbunched beam, obtained from COTR images on the same shot, is < 3 microns. The combined results show that the microbunched distribution has estimated transverse normalized emittance ~0.5 mm mrad.

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A. H. Lumpkin, M. LaBerge, D. W. Rule, R. Zgadzaj, A. Hannasch, O. Zarini, B. Bowers, A. Irman, J. P. Couperus-Cabadag, A. Debus, A. Köhler, U. Schramm, M. C. Downer. 2019-07-11. Interferometric optical signature of electron microbunching in laser-driven plasma accelerators. https://doi.org/10.1103/physrevlett.125.014801

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