A5050858120- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Magnetic confinement fusion research
- Laser Design and Applications
- Atomic and Molecular Physics
- High-pressure geophysics and materials
- Orbital Angular Momentum in Optics
- Plasma Diagnostics and Applications
- Solar and Space Plasma Dynamics
- Advanced Fiber Laser Technologies
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Particle physics theoretical and experimental studies
- Pulsed Power Technology Applications
- Gamma-ray bursts and supernovae
- Advanced X-ray Imaging Techniques
- Gyrotron and Vacuum Electronics Research
- Ionosphere and magnetosphere dynamics
- Advanced Surface Polishing Techniques
- Radiation Therapy and Dosimetry
- Dark Matter and Cosmic Phenomena
- Space Satellite Systems and Control
University of Lisbon
2015-2024
Beaumont Hospital
2024
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2024
Instituto Politécnico de Lisboa
2012-2023
Instituto Superior Técnico
2009-2023
Campbell Collaboration
2020-2022
Instituto Superior de Tecnologias Avançadas
2007-2020
Energetics (United States)
2019
University of Rochester
2019
Google (United States)
2019
The extraordinary ability of space-charge waves in plasmas to accelerate charged particles at gradients that are orders magnitude greater than current accelerators has been well documented. We develop a phenomenological framework for laser wakefield acceleration (LWFA) the 3D nonlinear regime, which plasma electrons expelled by radiation pressure short pulse laser, leading nearly complete blowout. Our theory provides recipe designing LWFA given and parameters estimates number energy...
Abstract Electron–positron pair plasmas represent a unique state of matter, whereby there exists an intrinsic and complete symmetry between negatively charged (matter) positively (antimatter) particles. These play fundamental role in the dynamics ultra-massive astrophysical objects are believed to be associated with emission ultra-bright gamma-ray bursts. Despite extensive theoretical modelling, our knowledge this matter is still speculative, owing extreme difficulty recreating neutral...
High energy particle accelerators have been crucial in providing a deeper understanding of fundamental particles and the forces that govern their interactions. In order to increase or reduce size accelerator, new acceleration schemes need be developed. Plasma wakefield acceleration, which electrons plasma are excited, leading strong electric fields, is one such promising novel technique. Pioneering experiments shown an intense laser pulse electron bunch traversing plasma, drives fields 10s...
We show analytically and through three-dimensional particle-in-cell simulations that non-linear wakefields driven by Laguerre-Gaussian laser pulses can lead to hollow electron self-injection positron acceleration. find higher order lasers drive donut shaped blowout with strong accelerating gradients comparable those of a spherical bubble. Corresponding focusing forces be more than an magnitude stronger in Required intensities energies reach the are within state-of-the-art experimental conditions.
Abstract Twisted Laguerre–Gaussian lasers, with orbital angular momentum and characterized by doughnut-shaped intensity profiles, provide a transformative set of tools research directions in growing range fields applications, from super-resolution microcopy ultra-fast optical communications to quantum computing astrophysics. The impact twisted light is widening as recent numerical calculations provided solutions long-standing challenges plasma-based acceleration allowing for high-gradient...
The acceleration of electrons to approximately 0.8 GeV has been observed in a self-injecting laser wakefield accelerator driven at plasma density 5.5x10(18) cm(-3) by 10 J, 55 fs, 800 nm pulse the blowout regime. is found be self-guided for 1 cm (>10zR), measurement single filament containing >30% initial energy this distance. Three-dimensional particle cell simulations show that intensity within guided amplified beyond its focused value normalized vector potential a0>6, thus driving highly...
A theory that describes how to load negative charge into a nonlinear, three-dimensional plasma wakefield is presented. In this regime, laser or an electron beam blows out the electrons and creates nearly spherical ion channel, which modified by presence of load. Analytical solutions for fields shape channel are derived. It shown very high beam-loading efficiency can be achieved, while energy spread bunch conserved. The theoretical results verified with Particle-In-Cell code OSIRIS.
The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment CERN the world׳s first experiment. AWAKE will be installed in former CNGS facility uses 400 GeV/c beam bunches from SPS. experiments focus on self-modulation instability of long (rms ~12 cm) bunch plasma. These are planned for end 2016. Later, 2017/2018, low energy (~15 MeV)...
The achievable energy and the stability of accelerated electron beams have been most critical issues in laser wakefield acceleration. As propagation, plasma wave formation acceleration are highly nonlinear processes, (LWFA) is extremely sensitive to initial experimental conditions. We propose a simple elegant waveform control method for LWFA process enhance performance accelerator by applying fully optical programmable technique chirp PW pulses. found dependence on spectral phase pulses...
We propose a twisted plasma accelerator capable of generating relativistic electron vortex beams with helical current profiles. The angular momentum these bunches is quantized, dominates their transverse motion, and results in spiraling particle trajectories around the wakefield. focus on laser wakefield acceleration scenario, driven by beam spatiotemporal intensity profile, also known as light spring. find that springs can rotate they excite wakefield, providing new mechanism to control...
We investigate the influence of a tilted laser-pulse-intensity front on laser-wakefield acceleration. Such asymmetric light pulses may be exploited to obtain control over electron-bunch-pointing direction and in our case allowed for reproducible electron-beam steering an all-optical way within 8 mrad opening window with respect initial laser axis. also discovered evidence collective electron-betatron oscillations due off-axis electron injection into wakefield induced by pulse-front tilt....
An analytical theory for the interaction of an electron bunch with a nonlinear plasma wave is developed to make it possible design efficient laser- and/or beam-driven accelerators that generate high quality monoenergetic beams. This shows how choose charge, shape, and placing so conversion efficiency from fields bubble accelerating electrons reaches nearly 100% beam optimized. For intense drivers wake described by shape loading arises when radial space-charge force acts back on sheath...
In this article we review the prospects of laser wakefield accelerators as next generation light sources for applications. This work arose a result discussions held at 2013 Laser Plasma Accelerators Workshop. X-ray phase contrast imaging, x-ray absorption spectroscopy, and nuclear resonance fluorescence are highlighted potential applications laser–plasma based sources. We discuss ongoing future efforts to improve properties radiation from plasma betatron emission Compton scattering using...
Using full-scale 3D particle-in-cell simulations we show that the radiation reaction dominated regime can be reached in an all optical configuration through collision of a $\sim$1 GeV laser wakefield accelerated (LWFA) electron bunch with counter propagating pulse. In this significantly reduces energy particle bunch, thus providing clear experimental signatures for process currently available lasers. We also transition between classical and quantum could investigated same intensities...
New acceleration technology is mandatory for the future elucidation of fundamental particles and their interactions. A promising approach to exploit properties plasmas. Past research has focused on creating large-amplitude plasma waves by injecting an intense laser pulse or electron bunch into plasma. However, maximum energy gain electrons accelerated in a single stage limited driver. Proton bunches are most drivers wakefields accelerate TeV scale stage. An experimental program at CERN—the...
A new generation of laser wakefield accelerators, supported by the extreme accelerating fields generated in interaction PW-Class lasers and underdense targets, promises production high quality electron beams short distances for multiple applications.Achieving this goal will rely heavily on numerical modeling further understanding underlying physics identification optimal regimes, but large scale these scenarios is computationally heavy requires efficient use state-of-the-art Petascale...
We present a new magnetic field generation mechanism in underdense plasmas driven by the beating of two, co-propagating, Laguerre-Gaussian (LG) orbital angular momentum (OAM) laser pulses with different frequencies and also twist indices. The resulting twisted ponderomotive force drives up an electron plasma wave helical rotating structure. To second order, there is nonlinear current leading to onset intense, static axial field, which persists over long time (ps scale) after have passed by....
We identify and explore a high orbital angular momentum (OAM) harmonics generation amplification mechanism that manipulates the OAM independently of any other laser property, by preserving initial wavelength, through stimulated Raman backscattering in plasma. The spectra can extend at least up to limiting value imposed paraxial approximation. show with theory particle-in-cell simulations orders be tuned according selection rule depends on interacting waves. illustrate plasma using several...
Current models predict the hose instability to crucially limit applicability of plasma-wakefield accelerators. By developing an analytical model which incorporates evolution over long propagation distances, this work demonstrates that inherent drive-beam energy loss, along with initial beam spread detune betatron oscillations electrons, and thereby mitigate instability. It is also shown tapered plasma profiles can strongly reduce hosing seeds. Hence, we demonstrate a drive be stabilized...
Spatiotemporal control refers to a class of optical techniques for structuring laser pulse with coupled spacetime-dependent properties, including moving focal points, dynamic spot sizes, and evolving orbital angular momenta. Here we introduce the concept arbitrarily structured (ASTRL) pulses, which generalizes these techniques. The ASTRL formalism employs superposition prescribed pulses create desired electromagnetic field structure. Several examples illustrate versatility address broad...
A laser beam's peak intensity may be programmed to move at an arbitrary velocity by adjusting the focal time and location of its frequencies, temporal slices, or annuli. Such ``flying focus'' beams show promise in enabling new laser-matter applications. To assess these possibilities, authors analytically describe electromagnetic fields flying-focus pulses with polarization orbital angular momentum.
We show in experiments that a long, underdense, relativistic proton bunch propagating plasma undergoes the oblique instability, which we observe as filamentation. determine threshold value for ratio between transverse size and skin depth instability to occur. At threshold, outcome of experiment alternates filamentation self-modulation (evidenced by longitudinal modulation into microbunches). Time-resolved images density distribution reveal grows an observable level late along bunch,...
Photon acceleration is the phenomenon whereby a light wave changes color when propagating through medium whose index of refraction in time. This concept can be used to describe spectral experienced by electromagnetic waves they propagate spatially and temporally varying plasmas. In this paper detection large-amplitude laser-driven wake field reported for first time, demonstrating photon acceleration. Several features characteristic fields, such as splitting main peak asymmetries between...
In 2004, using a 3D particle-in-cell (PIC) model [F. S. Tsung et al., Phys. Rev. Lett. 93, 185004 (2004)], it was predicted that 16.5TW, 50fs laser propagating through nearly 0.5cm of 3×1018cm−3 preformed plasma channel would generate monoenergetic bunch electrons with central energy 240MeV after propagation. addition, out to 840MeV were seen if the propagated 0.8cm same plasma. The simulations showed self-injection occurs intensity increases due combination photon deceleration, group...