Speaker
Description
Narrow energy spread beams with high spectral density and minimal dark current are critical for a wide range of applications. We report results from both experiments and simulations aimed at optimising these key parameters using laser wakefield accelerators. A fully automated experiment using Bayesian optimisation, controlling only the laser focal position and spectral phase, was used to achieve low energy spread electron beams with minimal dark current above 20 MeV. High fidelity simulations that closely match the experiment reveal the key role played by spectral phase terms in optimising accelerator performance. In particular, third-order dispersion plays a vital role in maximising beam charge, with a slight positive skew increasing the wake amplitude at the moment of injection. Simulations are further used to explore optimal trade-offs between beam parameters for the experimentally studied case and for next generation laser wakefield acceleration systems.
