Sep 15 – 21, 2019
Hotel Hermitage, La Biodola Bay, Isola d'Elba, Italy
Europe/Rome timezone

High Flux X-ray Emission from a Large Radius Electron Bunch that was Injected after Significant Pulse Compression in a Laser Wakefield Accelerator

Sep 19, 2019, 6:00 PM
SE (Hotel Hermitage)


Hotel Hermitage

talk WG4-WG6 Joint Session WG4-WG6


Jonathan Wood (Imperial College London)


A Laser Wakefield Accelerator producing two distinct electron populations: a 2 GeV component that was self-injected early in the interaction, and a sub-GeV component injected close to the laser depletion length, was shown to be an intense source of betatron x-rays. The x-rays were predominantly generated by the sub-GeV bunch.
Simultaneous measurements of the electron and x-ray spectra demonstrated that the larger oscillation radius of the sub-GeV beam was the main driver of the increased flux of emitted radiation, while the lower energy gain ensured moderate photon energies of 10-20 keV.
As many as $5 \times 10^{10}$ x-ray photons with energies > 1 keV were recorded per laser shot, which has led to a significant improvement in the signal to noise ratio of betatron radiography images.
3D particle-in-cell simulations demonstrate that the first bunch was injected after the initially oversized laser spot underwent rapid self-focussing to the matched spot size. Continuous temporal compression and power amplification of the drive pulse in the wakefield increased the width and length of the wakefield bubble through increased $a_0$, leading to the injection of a second electron bunch with higher transverse momentum.

Primary authors

Jonathan Wood (Imperial College London) Kristjan Poder (DESY) Dr Nelson Lopes (Instituto Superior Técnico) Jason Cole (Imperial College London) Dr Saleh Alatabi (Imperial College London) Dr Peta Foster (STFC Rutherford Appleton Laboratory) CHRISTOS KAMPERIDIS (ELI-ALPS, HU) Lena Kononenko (Ecole Polytechnique) Stuart Mangles (Imperial College London) Charlotte Palmer (Lancaster University/Cockcroft Institute) Dr Dean Rusby (STFC Rutherford Appleton Laboratory) Gianluca Sarri (Queen's University Belfast) Dr Matthew Streeter (Imperial College London) Daniel Symes (Rutherford Appleton Laboratory) J Warwick (Queen's University Belfast) Zulfikar Najmudin (Imperial College London)

Presentation materials