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Proceedings Paper

Betatron x-ray radiation in the self-modulated wakefield acceleration regime (Conference Presentation)
Author(s): Felicie Albert

Paper Abstract

Betatron x-ray radiation, driven by electrons from laser-wakefield acceleration, has unique properties to probe high energy density (HED) plasmas and warm dense matter. Betatron radiation is produced when relativistic electrons oscillate in the plasma wake of a laser pulse. Its properties are similar to those of synchrotron radiation, with a 1000 fold shorter pulse. This presentation will focus on the experimental challenges and results related to the development of betatron radiation in the self modulated regime of laser wakefield acceleration. We observed multi keV Betatron x-rays from a self-modulated laser wakefield accelerator. The experiment was performed at the Jupiter Laser Facility, LLNL, by focusing the Titan short pulse beam (4-150 J, 1 ps) onto the edge of a Helium gas jet at electronic densities around 1019 cm-3. For the first time on this laser system, we used a long focal length optic, which produced a laser normalized potential a0 in the range 1-3. Under these conditions, electrons are accelerated by the plasma wave created in the wake of the light pulse. As a result, intense Raman satellites, which measured shifts depend on the electron plasma density, were observed on the laser spectrum transmitted through the target. Electrons with energies up to 200 MeV, as well as Betatron x-rays with critical energies around 20 keV, were measured. OSIRIS 2D PIC simulations confirm that the electrons gain energy both from the plasma wave and from their interaction with the laser field.

Paper Details

Date Published: 21 June 2017
PDF: 1 pages
Proc. SPIE 10234, Relativistic Plasma Waves and Particle Beams as Coherent and Incoherent Radiation Sources II, 1023402 (21 June 2017); doi: 10.1117/12.2265936
Show Author Affiliations
Felicie Albert, Lawrence Livermore National Lab. (United States)

Published in SPIE Proceedings Vol. 10234:
Relativistic Plasma Waves and Particle Beams as Coherent and Incoherent Radiation Sources II
Dino A. Jaroszynski, Editor(s)

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