A5002430030- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- Laser Design and Applications
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Gyrotron and Vacuum Electronics Research
- Magnetic confinement fusion research
- Atomic and Molecular Physics
- Plasma Diagnostics and Applications
- Pulsed Power Technology Applications
- High-pressure geophysics and materials
- Advanced X-ray Imaging Techniques
- Advanced Fiber Laser Technologies
- Advanced Surface Polishing Techniques
- Laser Material Processing Techniques
- Terahertz technology and applications
- Diamond and Carbon-based Materials Research
- Ion-surface interactions and analysis
- Nuclear Physics and Applications
- Advanced Optical Sensing Technologies
- Photonic Crystal and Fiber Optics
- Photonic and Optical Devices
- Solid State Laser Technologies
- Particle Detector Development and Performance
Deutsches Elektronen-Synchrotron DESY
2019-2024
Universität Hamburg
2021-2024
Lawrence Berkeley National Laboratory
2013-2022
University of California, Berkeley
2012-2021
Berkeley College
2008-2020
Graduate Theological Union
2016
Helmholtz Institute Jena
2016
Eindhoven University of Technology
2016
University of Notre Dame
2015
Tech-X Corporation (United States)
2005-2014
Laser-driven plasma-based accelerators, which are capable of supporting fields in excess $100\phantom{\rule{0.3em}{0ex}}\mathrm{GV}∕\mathrm{m}$, reviewed. This includes the laser wakefield accelerator, plasma beat wave self-modulated waves driven by multiple pulses, and highly nonlinear regimes. The properties linear discussed, as well electron acceleration waves. Methods for injecting trapping electrons also discussed. Limits to energy gain summarized, including pulse diffraction,...
Multi-GeV electron beams with energy up to 4.2 GeV, 6% rms spread, 6 pC charge, and 0.3 mrad divergence have been produced from a 9-cm-long capillary discharge waveguide plasma density of ≈7×1017 cm−3, powered by laser pulses peak power PW. Preformed waveguides allow the use lower compared unguided structures achieve same beam energy. A detailed comparison between experiment simulation indicates sensitivity in this regime guiding acceleration structure input intensity, density, near-field...
Guiding of relativistically intense laser pulses with peak power 0.85 PW over 15 diffraction lengths was demonstrated by increasing the focusing strength a capillary discharge waveguide using inverse bremsstrahlung heating. This allowed for production electron beams quasimonoenergetic peaks up to 7.8 GeV, double energy that previously demonstrated. Charge 5 pC at GeV and 62 in 6 peaks, typical beam divergence 0.2 mrad.
An injector and accelerator is analyzed that uses three collinear laser pulses in a plasma: an intense pump pulse, which generates large wake field $(\ensuremath{\ge}20\mathrm{GV}/\mathrm{m})$, two counterpropagating injection pulses. When the collide, slow phase velocity beat wave generated injects electrons into fast for acceleration. Particle tracking simulations 1D with pulse intensities near ${10}^{17}\mathrm{W}/\mathrm{cm}{}^{2}$ indicate production of relativistic bunch durations as...
Pulses of x-rays 300 femtoseconds in duration at a wavelength 0.4 angstroms (30,000 electron volts) have been generated by 90° Thomson scattering between infrared terawatt laser pulses and highly relativistic electrons from an accelerator. In the right-angle geometry, x-ray burst is determined transit time pulse across ∼90-micrometer waist focused beam. The are directed (∼0.6° divergence) can be tuned energy. This source femtosecond will make it possible to combine techniques with ultrafast...
Plasma density gradients in a gas jet were used to control the wake phase velocity and trapping threshold laser wakefield accelerator, producing stable electron bunches with longitudinal transverse momentum spreads more than 10 times lower previous experiments (0.17 0.02 MeV/c FWHM, respectively) central momenta of 0.76+/-0.02 MeV/c. Transition radiation measurements combined simulations indicated that can be as accelerator injector produce beams 0.2 MeV/c-class spread at high energies.
Surfing a plasma wave, bunch of electrons or positrons can experience much higher accelerating gradients than conventional RF linac could provide.
Physics considerations for a next-generation linear collider based on laser-plasma accelerators are discussed. The ultrahigh accelerating gradient of accelerator and short laser coupling distance between stages allows compact linac. Two regimes acceleration highly nonlinear regime has the advantages higher fields uniform focusing forces, whereas quasilinear advantage symmetric properties electrons positrons. Scaling various parameters with respect to plasma density wavelength derived....
Abstract Plasma-based accelerators use the strong electromagnetic fields that can be supported by plasmas to accelerate charged particles high energies. Accelerating field structures in plasma generated powerful laser pulses or particle beams. This research has recently transitioned from involving a few small-scale efforts development of national and international networks scientists substantial investment large-scale infrastructure. In this New Journal Physics 2020 Plasma Accelerator...
Ultrafast lasers reaching extremely high powers within short fractions of time enable a plethora applications. They grant advanced material processing capabilities, are effective drivers for secondary photon and particle sources, reveal extreme light-matter interactions. also supply platforms compact accelerator technologies, with great application prospects tumor therapy or medical diagnostics. Many these scientific cases benefit from sources higher average peak powers. Following...
Coherent radiation in the 0.3-3 THz range has been generated from femtosecond electron bunches at a plasma-vacuum boundary via transition radiation. The produced by laser-plasma accelerator contained 1.5 nC of charge. energy per pulse within limited 30 mrad collection angle was 3-5 nJ and scaled quadratically with bunch charge, consistent coherent emission. Modeling indicates that this broadband source produces about 0.3 microJ 100 angle, increasing transverse plasma size beam could provide...
High-gradient acceleration of externally injected 2.1-MeV electrons by a laser beat wave driven relativistic plasma has been demonstrated for the first time. Electrons with energies up to detection limit 9.1 MeV were detected when such was resonantly excited using two-frequency laser. This implies gradient 0.7 GeV/m, corresponding plasma-wave amplitude more than 8%. The electron signal below threshold without injection or operated on single frequency.
Spontaneous radiation emitted from relativistic electrons undergoing betatron motion in a plasma-focusing channel is analyzed, and applications to plasma wake-field accelerator experiments the ion-channel laser (ICL) are discussed. Important similarities differences between free electron (FEL) an ICL delineated. It shown that frequency of spontaneous strong function strength parameter a(beta), which plays role similar wiggler conventional FEL. For a(beta) > or approximately 1, numerous...
The tunneling-ionization model predicts that fully ionized plasmas with controllable perpendicular (${\mathit{T}}_{\mathrm{\ensuremath{\perp}}}$) and negligible longitudinal temperature (${\mathit{T}}_{\mathrm{\ensuremath{\parallel}}}$) can be produced. validity of these predictions has been studied through experiments supporting theory simulations. Emission odd harmonics the laser frequency, indicative a stepwise ionization process, observed. X-ray measurements show plasma is higher for...
The temporal profile of relativistic laser-plasma-accelerated electron bunches has been characterized. Coherent transition radiation at THz frequencies, emitted the plasma-vacuum boundary, was measured through electro-optic sampling. Frequencies up to crystal detection limit 4 were observed. Comparison between data and theory indicates that from with structure shorter than $\ensuremath{\simeq}50\text{ }\text{ }\mathrm{fs}$ (root-mean-square) is emitted. measurement demonstrates both...
X-ray spectroscopy is used to obtain single-shot information on electron beam emittance in a low-energy-spread 0.5 GeV-class laser-plasma accelerator. Measurements of betatron radiation from 2 20 keV CCD and single-photon counting techniques. By matching x-ray spectra models, the bunch radius inside plasma estimated be $\ensuremath{\sim}0.1\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$. Combining this with simultaneous spectra, normalized transverse as low 0.1 mm mrad, consistent...
Compact, tunable, radially symmetric focusing of electrons is critical to laser-plasma accelerator (LPA) applications. Experiments are presented demonstrating the use a discharge-capillary active plasma lens focus 100-MeV-level LPA beams. The can provide tunable field gradients in excess 3000 T/m, enabling cm-scale focal lengths for GeV-level beam energies and allowing LPA-based electron beams light sources maintain their compact footprint. For range strengths, excellent agreement with...
Ionization injection in a laser-plasma accelerator is studied analytically and by multi-dimensional particle-in-cell (PIC) simulations. To enable the production of low energy spread beams, we consider short region containing high atomic number gas (e.g., nitrogen) for ionization-induced trapping, followed longer using hydrogen), that is, free additional post acceleration. For broad laser pulse, ionization requires minimum normalized field a0≃1.7, assuming resonant Gaussian pulse. Effects mix...
The interaction of high-energy electrons, positrons, and photons with intense laser pulses is studied in head-on collision geometry. It shown that electrons and/or positrons undergo a cascade-type process involving multiple emissions photons. These can consequently convert into electron-positron pairs. As result charged particles quickly lose their energy developing an exponentially decaying distribution, which suppresses the emission photons, thus reducing number pairs being generated....
A laser system producing controllable and stable pulses with high power ultrashort duration at repetition rate is a key component of energy laser-plasma accelerator (LPA). Precise characterization control properties are essential to understanding interactions required build 10-GeV class LPA. This paper discusses the diagnostics, performance parameters 1 Hz, petawatt (PW) Berkeley Lab Laser Accelerator (BELLA) facility. The BELLA PW provided up 46 J on target 1% level fluctuation 1.3-μrad...
A method is proposed to generate femtosecond, ultralow emittance (∼10-8 m rad), electron beams in a laser-plasma accelerator using two lasers of different colors. long-wavelength pump pulse, with large ponderomotive force and small peak electric field, excites wake without fully ionizing high-Z gas. short-wavelength injection copropagating delayed respect the laser, ionizes fraction remaining bound electrons at trapping phase, generating an beam that accelerated wake.