Related papers: Self-modulated laser wakefield accelerators as x-r…
Experimental results, supported by precise modelling, demonstrate optimisation of a plasma-based injector with intermediate laser pulse energy ($<1$ J), corresponding to a normalised vector potential $a_0 = 2.15$, using ionisation injection…
We study electron acceleration within a sub-critical plasma channel irradiated by an ultra-intense laser pulse ($a_0>100$ or $I>10^{22}~\mathrm{W/cm^2}$). In this regime, radiation reaction significantly alters the electron dynamics. This…
We revisit the matching conditions for self-guided laser pulse propagation in plasma and refine their formulation to maximize the energy of electrons produced via laser wakefield acceleration. Bayesian optimization, combined with…
In the cavitation regime of plasma-based accelerators, a population of high-energy electrons tailing the driver can undergo betatron motion. The motion results in X-ray emission, but the brilliance and photon energy are limited by the…
Single-shot absorption measurements have been performed using the multi-keV X-rays generated by a laser wakefield accelerator. A 200 TW laser was used to drive a laser wakefield accelerator in a mode which produced broadband electron beams…
In this dissertation, a fully object-oriented, fully relativistic, multi-dimensional Particle-In-Cell code was developed and applied to answer key questions in plasma-based accelerator research. The simulations increase the understanding of…
We propose to use a frequency doubled pulse colliding with the driving pulse at an acute angle to trigger ionization injection in a laser wakefield accelerator. This scheme effectively reduces the duration that injection occurs, thus high…
A long laser beam propagating through an underdense plasma produces a positively charged ion channel by expelling plasma electrons in the transverse direction. We consider the dynamics of a test electron in a resulting two-dimensional…
X-ray free-electron lasers are large and complex machines, limited by electron beam brightness. Here we show through start-to-end simulations how to realise compact, robust and tunable X-ray lasers in the water window, based on ultra-bright…
The quality of electron beams produced from plasma-based accelerators, i.e., normalized brightness and energy spread, has made transformative progress in the past several decades in both simulation and experiment. Recently, full-scale…
Positron acceleration in plasma wakefield faces significant challenges since the positron beam must be pre-generated and precisely coupled into the wakefield, and most critically, suffers from defocusing issues. Here we propose a scheme…
Petawatt-class lasers can produce multi-GeV electron beams through laser wakefield electron acceleration. As a by-product, the accelerated electron beams can generate broad synchrotron-like radiation known as betatron radiation. In the…
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…
Direct Laser Acceleration (DLA) of electrons during a high-energy, picosecond laser interaction with an underdense plasma has been demonstrated to be substantially enhanced by controlling the laser focusing geometry. Experiments using the…
We investigate the extension of self-injecting laser wakefield experiments to the regime that will be accessible with the next generation of petawatt class ultra-short pulse laser systems. Using linear scalings, current experimental trends…
Laser wakefield acceleration of electrons represents a basis for several types of novel X-ray sources based on Thomson scattering or betatron radiation. The latter provides a high photon flux and a small source size, both being…
The irradiation of few nm thick targets by a finite-contrast high-intensity short-pulse laser results in a strong pre-expansion of these targets at the arrival time of the main pulse. The targets decompress to near and lower than critical…
The dynamics of electron injection in the direct laser acceleration (DLA) regime was investigated by means of three-dimensional particle-in-cell simulations and theoretical analysis. It is shown that when an ultra-intense laser pulse…
We report on experimental measurements of energy transfer efficiencies in a GeV-class laser wakefield accelerator. Both the transfer of energy from the laser to the plasma wakefield, and from the plasma to the accelerated electron beam were…
We report a laser wakefield acceleration of electron beams up to 130 MeV from laser-driven 4-mm long nitrogen gas jet. By using a moderate laser intensity (3.5*10^18 W.cm^(-2)) and relatively low plasma densities (0.8*10^18 cm^(-3) to…