Spectral phase control for optimized ionization injection in laser wakefield acceleration
Year: 2025
Type: article
Abstract: Generating narrow energy spread beams from laser wakefield accelerators with minimal dark current is important for many applications. We present an automated experiment using Bayesian optimization to control the laser spectral phase and focal position, achieving significant enhancement of the beam quality. Starting from a broadband spectrum, the optimized configuration achieved low-energy spread with negligible dark current above 20 MeV. Particle-in-cell simulations reveal that fine control over the laser spectral phase, particularly third-order dispersion, directly impacts the timing and localization of ionization injection due to its effect on the initial laser intensity envelope and its subsequent evolution. A positively skewed temporal profile enhances the plasma potential depth at the right location, enabling localized injection and reducing the energy spread and dark current. These findings highlight the impact of algorithmic optimization and the powerful, underutilized role of temporal shaping in beam quality control.
DOI: 10.1103/9gjq-htzn
Institutions: Imperial College London, University of Strathclyde, Laboratoire de Physiologie et Génomique des Poissons, University of York, National Agency for New Technologies, Energy and Sustainable Economic Development, Lund University, Queen's University Belfast, Deutsches Elektronen-Synchrotron DESY, Central Laser Facility, Laboratoire Interactions, Dynamiques et Lasers
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
Funders: Royal Society, European Commission, Knut och Alice Wallenbergs Stiftelse, Vetenskapsrådet, Centre National de la Recherche Scientifique, Defence Science and Technology Laboratory, Horizon 2020 Framework Programme, Engineering and Physical Sciences Research Council, Science and Technology Facilities Council
Awards: The John Adams Institute for Accelerator Science, G2214510774, Fundamental studies and applications of laser-based accelerators, G2898032196, G2975900969, G4077823627, G434337789, The John Adams Institute for Accelerator Science, G5091866801, G5211475403, Industrial CASE Account - Imperial College 2018, G6907965553, Accelerator Research and Innovation for European Science and Society, The John Adams Institute for Accelerator Science, Fundamental studies and applications of laser-based accelerators, G988628021
OpenAlex ID: W4416935806