A5081767709- Laser-Plasma Interactions and Diagnostics
- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Laser-induced spectroscopy and plasma
- Plasma Diagnostics and Applications
- Laser-Matter Interactions and Applications
- Magnetic confinement fusion research
- Particle Detector Development and Performance
- Laser Design and Applications
- Distributed and Parallel Computing Systems
- Advanced X-ray Imaging Techniques
- High-pressure geophysics and materials
- Diamond and Carbon-based Materials Research
- Advanced Data Storage Technologies
- Parallel Computing and Optimization Techniques
- Advanced Surface Polishing Techniques
- Pulsed Power Technology Applications
- Simulation Techniques and Applications
- Advanced Optical Sensing Technologies
- Laser Material Processing Techniques
- Electromagnetic Simulation and Numerical Methods
- Nuclear Physics and Applications
- Superconducting Materials and Applications
- Atomic and Molecular Physics
- Scientific Computing and Data Management
Lawrence Berkeley National Laboratory
2016-2025
Lawrence Livermore National Security
2021
Centre National de la Recherche Scientifique
2013-2018
University of California, Berkeley
2009-2018
Université Paris-Sud
2016-2018
Université Paris-Saclay
2016-2018
Laboratoire d'Optique Appliquée
2012-2016
École Polytechnique
2013-2016
École Nationale Supérieure de Techniques Avancées
2013-2016
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2016
Turning the current experimental plasma accelerator state-of-the-art from a promising technology into mainstream scientific tools depends critically on high-performance, high-fidelity modeling of complex processes that develop over wide range space and time scales. As part U.S. Department Energy's Exascale Computing Project, team Lawrence Berkeley National Laboratory, in collaboration with teams SLAC Accelerator Laboratory Livermore is developing new simulation tool will harness power future...
Generating high-quality laser-plasma accelerated electron beams requires carefully balancing a plethora of physical effects and is therefore challenging---both conceptually in experiments. Here, we use Bayesian optimization key laser plasma parameters to flatten the longitudinal phase space an ionization-injected bunch via optimal beam loading. We first study concept with particle-in-cell simulations then demonstrate it Starting from arbitrary set point, accelerator autonomously tunes energy...
(150 word max) We present a first-of-kind mesh-refined (MR) massively parallel Particle-In-Cell (PIC) code for kinetic plasma simulations optimized on the Frontier, Fugaku, Summit, and Perlmutter supercomputers. Major innovations, implemented in WarpX PIC code, include: (i) three level parallelization strategy that demonstrated performance portability scaling millions of A64FX cores tens thousands AMD Nvidia GPUs (ii) groundbreaking mesh refinement capability provides between 1.5 x to 4...
Accelerator physics relies on numerical algorithms to solve optimization problems in online accelerator control and tasks such as experimental design model calibration simulations. The effectiveness of discovering ideal solutions for complex challenges with limited resources often determines the problem complexity these methods can address. community has recognized advantages Bayesian algorithms, which leverage statistical surrogate models objective functions effectively address challenges,...
Transverse emittance is a crucial feature of laser-wakefield accelerators, yet accurately reproducing its value in numerical simulations remains challenging. It shown here that, when the charge bunch exceeds few tens picocoulombs, particle-in-cell (PIC) erroneously overestimate emittance. This mostly due interaction spurious Cherenkov radiation with bunch, which leads to steady growth during simulation. A new computational scheme proposed, free radiation. can be easily implemented existing...
Laser-plasma technology promises a drastic reduction of the size high energy electron accelerators. It could make free lasers available to broad scientific community, and push further limits accelerators for physics. Furthermore unique femtosecond nature source makes it promising tool study ultra-fast phenomena. However, applications are hindered by lack suitable lens transport this kind high-current beams, mainly due their divergence. Here we show that issue can be solved using laser-plasma...
Many theoretical and experimental studies suggest that range expansions can have severe consequences for the gene pool of expanding population. Due to strongly enhanced genetic drift at advancing frontier, neutral weakly deleterious mutations reach large frequencies in newly colonized regions, as if they were surfing front expansion. These findings raise question how frequently beneficial successfully surf shifting margins, thereby promoting adaptation towards a range-expansion phenotype....
Thanks to their compactness and unique properties, laser-wakefield accelerators are currently considered for several innovative applications. However, many of these applications---and especially those that require beam transport---are hindered by the large divergence laser-accelerated beams. Here we propose a collimating concept relies on strong radial electric field reduce this divergence. This utilizes an additional gas jet, placed after accelerator. When laser pulse propagates through it...
The recent advances in developing compact laser plasma accelerators that deliver high quality electron beams a more reliable way offer the possibility to consider their use designing free (FEL). Because of particularity these (especially concerning divergence and energy spread), specific beam handling is proposed order achieve FEL amplification.
Single-shot, charge-dependent emittance measurements of electron beams generated by a laser plasma accelerator (LPA) reveal that shock-induced density down-ramp injection produces with normalized emittances factor 2 smaller than produced via ionization injection. Such comparison is made possible the tunable LPA setup, which allows nearly identical central energy and peak spectral charge to be using two distinct mechanisms. Parametric this type are essential for development LPA-based...
Control of the properties laser-plasma-accelerated electron beams that were injected along a shock-induced density downramp through precision tailoring profile was demonstrated using 1.8 J, 45 fs laser interacting with mm-scale gas jet. The effects on beam spatial profile, steering, and absolute energy spread region before shock tilt investigated experimentally particle-in-cell simulations. By adjusting these parameters, quality controlled improved while (30--180 MeV) (2--11 independently...
WarpX is a general purpose electromagnetic particle-in-cell code that was originally designed to run on many-core CPU architectures. We describe the strategy, based AMReX library, followed allow use GPU-accelerated nodes OLCF’s Summit supercomputer, strategy we believe will extend upcoming machines Frontier and Aurora. summarize challenges encountered, lessons learned, give current performance results series of relevant benchmark problems.
The fully electromagnetic particle-in-cell code WarpX is being developed by a team of the U.S. DOE Exascale Computing Project (with additional non-U.S. collaborators on part code) to enable modeling chains tens hundreds plasma accelerator stages exascale supercomputers, for future collider designs. combining latest algorithmic advances (e.g., Lorentz boosted frame and pseudo-spectral Maxwell solvers) with mesh refinement runs computer processing unit graphical (GPU) architectures. In this...
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...
Laser-wakefield acceleration constitutes a promising technology for future electron accelerators. A crucial step in such an accelerator is the injection of electrons into wakefield, which will largely determine properties extracted beam. We present here new paradigm colliding-pulse injection, allows us to generate high-quality bunches having both very low emittance ($0.17\text{ }\text{ }\mathrm{mm}\ifmmode\cdot\else\textperiodcentered\fi{}\mathrm{mrad}$) and energy spread (2%), while...
The injection physics in a shock-induced density down-ramp injector was characterized, demonstrating precise control of laser-plasma accelerator (LPA). Using jet-blade assembly, experiments systematically varied the shock profile, including angle, position, up-ramp width, and acceleration length. Our work demonstrates that beam energy, energy spread, pointing can be controlled by adjusting these parameters. As result, an electron highly tunable from 25 to 300 MeV with 8% spread (ΔEFWHM/E),...
Modeling plasma accelerators is a computationally challenging task and the quasi-static particle-in-cell algorithm method of choice in wide range situations. In this work, we present first performance-portable, quasi-static, three-dimensional code HiPACE++. By decomposing all computation 3D domain successive 2D transverse operations choosing appropriate memory management, HiPACE++ demonstrates orders-of-magnitude speedups on modern scientific GPUs over CPU-only implementations. The are...
Abstract Laser-plasma accelerators are capable of sustaining accelerating fields 10–100 GeV/m, 100–1000 times that conventional technology and the highest produced by any widely researched advanced accelerator concepts. also intrinsically accelerate short particle bunches, several orders magnitude shorter than technology, which leads to reductions in beamstrahlung and, hence, savings overall power consumption reach a desired luminosity. These properties make laser-plasma promising for more...
The particle-in-cell (PIC) and Monte Carlo collisions (MCC) methods are workhorses of many numerical simulations physical systems. Recently, it was pointed out that, while the two can be exactly—or nearly—energy-conserving independently, combining leads to anomalous heating. This paper reviews standard explicit PIC-MCC algorithm, elucidates origins heating, explains how couple such that heating is avoided. Published by American Physical Society 2025
This document outlines a community-driven Design Study for 10 TeV pCM Wakefield Accelerator Collider. The 2020 ESPP Report emphasized the need Advanced R\&D, and 2023 P5 calls ``delivery of an end-to-end design concept, including cost scales, with self-consistent parameters throughout." leverages recent experimental theoretical progress resulting from global R\&D program in order to deliver unified, Collider concept. Accelerators provide ultra-high accelerating gradients which enables...
We study the heating of charged test particles in three-dimensional numerical simulations weakly compressible magnetohydrodynamic (MHD) turbulence (``Alfvenic turbulence''); these results are relevant to particle and acceleration solar wind, flares, accretion disks onto black holes, other astrophysics heliospheric environments. The physics depends on whether gyrofrequency a is comparable frequency turbulent fluctuation that resolved computational domain. Particles with frequencies nearly...
Particle in Cell (PIC) simulations are a widely used tool for the investigation of both laser- and beam-driven plasma acceleration. It is known issue that beam quality can be artificially degraded by numerical Cherenkov radiation (NCR) resulting primarily from an incorrectly modeled dispersion relation. Pseudo-spectral solvers featuring infinite order stencils strongly reduce NCR—or even suppress it—and therefore well suited to correctly model properties. For efficient parallelization PIC...