A. Martínez de la Ossa
A5043392383- Laser-Plasma Interactions and Diagnostics
- Particle Accelerators and Free-Electron Lasers
- Particle physics theoretical and experimental studies
- Particle accelerators and beam dynamics
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Laser-induced spectroscopy and plasma
- Magnetic confinement fusion research
- Laser-Matter Interactions and Applications
- Pulsed Power Technology Applications
- Dark Matter and Cosmic Phenomena
- Plasma Diagnostics and Applications
- Neutrino Physics Research
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Atomic and Molecular Physics
- High-pressure geophysics and materials
- Advanced Surface Polishing Techniques
- Particle Detector Development and Performance
- Nuclear Physics and Applications
- Astrophysics and Cosmic Phenomena
- Laser Material Processing Techniques
- Laser Design and Applications
- Ion-surface interactions and analysis
- Parkinson's Disease Mechanisms and Treatments
Deutsches Elektronen-Synchrotron DESY
2015-2025
Corporación Universitaria Comfacauca - Unicomfacauca
2024
Universität Hamburg
2013-2019
Vall d'Hebron Institut de Recerca
2016
Universitat Autònoma de Barcelona
2013-2016
University of Colorado Boulder
2009-2015
Hamburg Institut (Germany)
2011-2015
Argonne National Laboratory
2013
Friedrich-Alexander-Universität Erlangen-Nürnberg
2011
Peking University
2010
Azimuthal single-spin asymmetries of lepto-produced pions and charged kaons were measured on a transversely polarized hydrogen target. Evidence for naive-T-odd, transverse-momentum-dependent parton distribution function is deduced from non-vanishing Sivers effects pi+, pi0, K+, K-, as well in the difference pi+ pi- cross sections.
Single-spin asymmetries for pions and charged kaons are measured in semi-inclusive deep-inelastic scattering of positrons electrons off a transversely nuclear-polarized hydrogen target. The dependence the cross section on azimuthal angles target polarization (phi_S)and produced hadron (phi) is found to have substantial sin(phi+phi_S) modulation production pi+, pi- K+. This Fourier component can be interpreted terms non-zero transversity distribution functions favored disfavored Collins...
Multiplicities in semi-inclusive deep-inelastic scattering are presented for each charge state of ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}$ and ${\mathrm{K}}^{\ifmmode\pm\else\textpm\fi{}}$ mesons. The data were collected by the HERMES experiment at HERA storage ring using 27.6 GeV electron positron beams incident on a hydrogen or deuterium gas target. results as function kinematic quantities ${x}_{\mathrm{B}}$, ${Q}^{2}$, $z$, ${P}_{h\ensuremath{\perp}}$. They represent unique set...
Abstract Radio-frequency (RF) accelerators providing high-quality relativistic electron beams are an important resource enabling many areas of science, as well industrial and medical applications. Two decades ago, laser-plasma 1 that support orders magnitude higher electric fields than those provided by modern RF cavities produced quasi-monoenergetic for the first time 2–4 . Since then, high-brightness at gigaelectronvolt (GeV) beam energy competitive properties have been demonstrated from...
The azimuthal cos{\phi} and cos2{\phi} modulations of the distribution hadrons produced in unpolarized semi-inclusive deep-inelastic scattering electrons positrons off hydrogen deuterium targets have been measured HERMES experiment. For first time these were determined a four-dimensional kinematic space for positively negatively charged pions kaons separately, as well unidentified hadrons. These dependences are sensitive to transverse motion polarization quarks within nucleon via, e.g.,...
Beam-helicity and beam-charge asymmetries in the hard exclusive leptoproduction of real photons from an unpolarised hydrogen target by a 27.6 GeV lepton beam are extracted HERMES data set 2006-2007 using missing-mass event selection technique. The asymmetry amplitudes this more precise than those earlier 1996-2005 previously analysed same manner HERMES. results two sets compatible with each other. Results these combined constitute most amplitude measurements made kinematic region
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...
A tunable plasma-based energy dechirper has been developed at FLASHForward to remove the correlated spread of a 681 MeV electron bunch. Through interaction bunch with wakefields excited in plasma projected was reduced from FWHM 1.31% 0.33% without reducing stability incoming beam. The experimental results for variable density are good agreement analytic predictions and three-dimensional simulations. proof-of-principle dechirping strength 1.8 GeV/mm/m significantly exceeds those demonstrated...
The Horizon 2020 Project EuPRAXIA ("European Plasma Research Accelerator with eXcellence In Applications") is preparing a conceptual design report of highly compact and cost-effective European facility multi-GeV electron beams using plasma as the acceleration medium. accelerator will be based on laser and/or beam driven approach used for photon science, high-energy physics (HEP) detector tests, other applications such X-ray sources medical imaging or material processing. started in November...
Abstract Plasma wakefield accelerators are capable of sustaining gigavolt-per-centimeter accelerating fields, surpassing the electric breakdown threshold in state-of-the-art accelerator modules by 3-4 orders magnitude. Beam-driven wakefields offer particularly attractive conditions for generation and acceleration high-quality beams. However, this scheme relies on kilometer-scale accelerators. Here, we report demonstration a millimeter-scale plasma powered laser-accelerated electron We...
Energy-efficient plasma-wakefield acceleration of particle bunches with low energy spread is a promising path to realizing compact free-electron lasers and colliders. High efficiency can be achieved simultaneously by strong beam loading plasma wakefields when accelerating carefully tailored current profiles [M. Tzoufras et al., Phys. Rev. Lett. 101, 145002 (2008)]. We experimentally demonstrate such optimal in nonlinear electron-driven accelerator. Bunches an initial 1 GeV were accelerated...
A bstract The beam-helicity asymmetry in exclusive electroproduction of real photons by the longitudinally polarized Hera positron beam scattering off an unpolarized hydrogen target is measured at Hermes. arises from deeply virtual Compton and its interference with Bethe-Heitler process. Azimuthal amplitudes are extracted a data sample consisting ep → epγ events detection all particles final state including recoiling proton. installation recoil detector, while reducing acceptance experiment,...
Double-spin asymmetries in exclusive electroproduction of real photons from a transversely polarized hydrogen target are measured with respect to the product polarization beam helicity and charge, alone. The arise deeply virtual Compton scattering process its interference Bethe--Heitler process. They related part same combination form factors as that determining previously published transverse single-spin through imaginary part. results for double-spin found be compatible zero within...
Particle-beam-driven plasma wakefield acceleration (PWFA) enables various novel high-gradient techniques for powering future compact light-source and high-energy physics applications. Here, a driving particle bunch excites response in medium, which may rapidly accelerate trailing witness beam. In this Letter, we present the measurement of ratios to deceleration driver bunch, so-called transformer ratio, significantly exceeding fundamental theoretical thus far experimental limit 2 PWFA. An...
Density down-ramp (DDR) injection is a promising concept in beam-driven plasma wakefield accelerators for the generation of high-quality witness beams. We review and complement theoretical principles method employ particle-in-cell (PIC) simulations order to determine constrains on geometry density ramp current drive beam, regarding applicability DDR injection. Furthermore, PIC are utilized find optimized conditions production explain intriguing result that an increased charge by means...
Polarisation asymmetries are measured for the hard exclusive leptoproduction of real photons from a longitudinally polarised hydrogen target. These arise deeply virtual Compton scattering and Bethe-Heitler processes. From data extracted two in azimuthal distribution produced about direction exchanged photon: $$ {\mathcal{A}_{\text{UL}}} with respect to target polarisation {\mathcal{A}_{\text{LL}}} product beam polarisations. Results both compared predictions generalised parton model. The sin...
We propose a new and simple strategy for controlled ionization-induced trapping of electrons in beam-driven plasma accelerator. The presented method directly exploits electric wakefields to ionize from dopant gas capture them into well-defined volume the accelerating focusing wake phase, leading high-quality witness bunches. This injection principle is explained by example three-dimensional particle-in-cell calculations using code OSIRIS. In these simulations high-current-density...
The extreme electromagnetic fields sustained by plasma-based accelerators could drastically reduce the size and cost of future accelerator facilities. However, they are also an inherent source correlated energy spread in produced beams, which severely limits usability these devices. We propose here to split acceleration process into two plasma stages joined a magnetic chicane correlation induced first stage is inverted such that it can be naturally compensated second. Simulations particular...
We present experimental results on a plasma wakefield accelerator (PWFA) driven by high-current electron beams from laser (LWFA). In this staged setup stable and high quality (low divergence low energy spread) are generated at an optically-generated hydrodynamic shock in the PWFA. The stability of produced that arrangement PWFA stage is comparable to both single-stage accelerators conventional accelerators. Simulations support intrinsic insensitivity PWFAs driver fluctuations can be...
Particle-in-cell simulations are among the most essential tools for modeling and optimization of laser-plasma accelerators, since they reproduce physics from first principles. However, high computational cost associated with them can severely limit scope parameter design studies. Here, we show that a multitask Bayesian algorithm be used to mitigate need such high-fidelity by incorporating information inexpensive evaluations reduced physical models. In proof-of-principle study, where fbpic is...
Exclusive electroproduction of pi+ mesons was studied by scattering 27.6 GeV positrons or electrons off a transversely polarized hydrogen target. The single-spin azimuthal asymmetry with respect to target polarization measured as function the Mandelstam variable t, Bjorken scaling x_B, and virtuality Q^2 exchanged photon. extracted Fourier components were found be consistent zero, except one that large involves interference contributions from longitudinal transverse virtual photons.