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arXiv · 1705.01181

High Flux Femtosecond X-ray Emission from the Electron-Hose Instability in Laser Wakefield Accelerators

Chuanfei Dong·T. Z. Zhao·K. Behm·P. G. Cummings·J. Nees·A. Maksimchuk·V. Yanovsky·K. Krushelnick·A. G. R. Thomas
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Abstract

Bright and ultrashort duration X-ray pulses can be produced by through betatron oscillations of electrons during Laser Wakefield Acceleration (LWFA). Our experimental measurements using the \textsc{Hercules} laser system demonstrate a dramatic increase in X-ray flux for interaction distances beyond the depletion/dephasing lengths, where the initial electron bunch injected into the first wake bucket catches up with the laser pulse front and the laser pulse depletes. A transition from an LWFA regime to a beam-driven plasma wakefield acceleration (PWFA) regime consequently occurs. The drive electron bunch is susceptible to the electron-hose instability and rapidly develops large amplitude oscillations in its tail, which leads to greatly enhanced X-ray radiation emission. We measure the X-ray flux as a function of acceleration length using a variable length gas cell. 3D particle-in-cell (PIC) simulations using a Monte Carlo synchrotron X-ray emission algorithm elucidate the time-dependent variations in the radiation emission processes.

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Chuanfei Dong, T. Z. Zhao, K. Behm, P. G. Cummings, J. Nees, A. Maksimchuk, V. Yanovsky, K. Krushelnick, A. G. R. Thomas. 2017-05-02. High Flux Femtosecond X-ray Emission from the Electron-Hose Instability in Laser Wakefield Accelerators. https://doi.org/10.1103/physrevaccelbeams.21.041303

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