A5039384359- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Laser-Matter Interactions and Applications
- Laser Design and Applications
- High-pressure geophysics and materials
- Atomic and Molecular Physics
- Combustion and Detonation Processes
- Magnetic confinement fusion research
- Advanced Fiber Laser Technologies
- Particle accelerators and beam dynamics
- Nuclear Physics and Applications
- Advanced Optical Sensing Technologies
- Plasma Diagnostics and Applications
- Particle Accelerators and Free-Electron Lasers
- Spectroscopy Techniques in Biomedical and Chemical Research
- Ion-surface interactions and analysis
- Cold Fusion and Nuclear Reactions
- Advanced X-ray Imaging Techniques
- Laser Material Processing Techniques
- Ocular and Laser Science Research
- Quantum optics and atomic interactions
- Solid State Laser Technologies
- Spectroscopy and Laser Applications
- Energetic Materials and Combustion
- Dust and Plasma Wave Phenomena
Lawrence Livermore National Laboratory
2016-2025
University of Alberta
2013-2022
University of Rochester
2012-2022
Energetics (United States)
2012-2022
Université Côte d'Azur
2022
Princeton University
2022
University of Oxford
2022
Sorbonne Université
2002-2020
Hôpital Tenon
2020
Université Sorbonne Nouvelle
2020
Indirect-drive hohlraum experiments at the National Ignition Facility have demonstrated symmetric capsule implosions unprecedented laser drive energies of 0.7 megajoule. One hundred and ninety-two simultaneously fired beams heat ignition-emulate hohlraums to radiation temperatures 3.3 million kelvin, compressing 1.8-millimeter-diameter capsules by soft x-rays produced hohlraum. Self-generated plasma optics gratings on either end tune power distribution in hohlraum, which produces a x-ray as...
The National Ignition Facility (NIF) at Lawrence Livermore Laboratory includes a precision laser system now capable of delivering 1.8 MJ 500 TW 0.35-μm light to target. NIF has been operational since March 2009. A variety experiments have completed in support NIF's mission areas: national security, fundamental science, and inertial fusion energy. capabilities infrastructure are place its missions with nearly 60 X-ray, optical, nuclear diagnostic systems. primary goal the Campaign (NIC) on...
Radiative hydrodynamics simulations of ignition experiments show that energy transfer between crossing laser beams allows tuning the implosion symmetry. A new full-scale, three-dimensional quantitative model has been developed for crossed-beam transfer, allowing calculations propagation and coupling multiple their associated plasma waves in hohlraums. This implemented a radiative-hydrodynamics code, demonstrating control symmetry by wavelength separation cones beams.
A series of cryogenic, layered deuterium-tritium (DT) implosions have produced, for the first time, fusion energy output twice peak kinetic imploding shell. These experiments at National Ignition Facility utilized high density carbon ablators with a three-shock laser pulse (1.5 MJ in 7.5 ns) to irradiate low gas-filled ($0.3\text{ }\text{ }\mathrm{mg}/\mathrm{cc}$ helium) bare depleted uranium hohlraums, resulting hohlraum radiative temperature $\ensuremath{\sim}290\text{ }\mathrm{eV}$. The...
The Hohlraum energetics experimental campaign started in the summer of 2009 on National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)]. These experiments showed good coupling laser energy into targets [N. Meezan 17, 056304 (2010)]. They have also demonstrated controlled crossed-beam transfer between beams as an efficient and robust tool to tune implosion symmetry ignition capsules, predicted by earlier calculations [P. Michel Rev. Lett. 102, 025004 A new linear...
The “High-Foot” platform manipulates the laser pulse-shape coming from National Ignition Facility to create an indirect drive 3-shock implosion that is significantly more robust against instability growth involving ablator and also modestly reduces convergence ratio. This strategy gives up on theoretical high-gain in inertial confinement fusion order obtain better control of bring experimental performance in-line with calculated performance, yet keeps absolute capsule relatively high. In...
Capsule performance optimization campaigns will be conducted at the National Ignition Facility [G. H. Miller, E. I. Moses, and C. R. Wuest, Nucl. Fusion 44, 228 (2004)] to substantially increase probability of ignition. The experimentally correct for residual uncertainties in implosion hohlraum physics used our radiation-hydrodynamic computational models using a variety ignition capsule surrogates before proceeding cryogenic-layered implosions experiments. quantitative goals technique...
Direct-drive-implosion experiments on the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] have showed discrepancies between simulations of scattered (non-absorbed) light levels and measured ones that indicate presence a mechanism reduces coupling efficiency by 10%–20%. This appears to be due crossed-beam energy transfer (CBET) involves electromagnetic-seeded, low-gain stimulated Brillouin scattering. CBET scatters from central portion incoming beam outgoing light, reducing...
A laser wakefield acceleration study has been performed in the matched, self-guided, blowout regime producing 720 +/- 50 MeV quasimonoenergetic electrons with a divergence Deltatheta_{FWHM} of 2.85 0.15 mrad using 10 J, 60 fs 0.8 microm laser. While maintaining nearly constant plasma density (3 x 10{18} cm{-3}), energy gain increased from 75 to when length was 3 8 mm. Absolute charge measurements indicate that self-injection occurs power P exceeds times critical P{cr} for relativistic...
Along with laser-indirect (X-ray)-drive and magnetic-drive target concepts, laser direct drive is a viable approach to achieving ignition gain inertial confinement fusion. In the United States, national program has been established demonstrate understand physics of drive. The utilizes Omega Laser Facility conduct implosion coupling at nominally 30-kJ scale laser–plasma interaction MJ National Ignition Facility. This article will discuss motivation challenges for broad-based presently...
Capsule implosions on the National Ignition Facility (NIF) [Lindl et al., Phys. Plasmas 11, 339 (2004)] are underway with goal of compressing deuterium-tritium (DT) fuel to a sufficiently high areal density (ρR) sustain self-propagating burn wave required for fusion power gain greater than unity. These driven carefully tailored sequence four shock waves that must be timed very precision in order keep DT low adiabat. Initial experiments measure strength and relative timing these shocks have...
The first series of experiments the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] tested ignition Hohlraum “energetics,” a term described by four broad goals: (1) measurement laser absorption Hohlraum; (2) x-ray radiation flux (TRAD4) on surrogate capsule; (3) quantitative understanding and resultant flux; (4) determining whether initial performance is consistent with requirements for ignition. This paper summarizes status NIF energetics experiments....
Planar laser-plasma interaction (LPI) experiments at the National Ignition Facility (NIF) have allowed access for first time to regimes of electron density scale length (∼500 700 μm), temperature (∼3 5 keV), and laser intensity (6 16×10^{14} W/cm^{2}) that are relevant direct-drive inertial confinement fusion ignition. Unlike in shorter-scale-length plasmas on OMEGA, scattered-light data NIF show near-quarter-critical LPI physics is dominated by stimulated Raman scattering (SRS) rather than...
We report on the most recent and successful effort at controlling trajectory symmetry of a high density carbon implosion National Ignition Facility. use low gasfill (0.3 mg/cc He) bare depleted uranium hohlraum with around 1 MJ laser energy to drive 3-shock-ignition relevant implosion. assess performance we demonstrate control convergence 1, 3–5, 12, 27 better than ±5 μm using succession experimental platforms. The was maintained peak fuel velocity 380 km/s. Overall, measurements are...
A detailed simulation-based model of the June 2011 National Ignition Campaign cryogenic DT experiments is presented. The based on integrated hohlraum-capsule simulations that utilize best available models for hohlraum wall, ablator, and equations state opacities. calculated radiation drive was adjusted by changing input laser power to match experimentally measured shock speeds, merger times, peak implosion velocity, bangtime. crossbeam energy transfer tuned time-dependent symmetry. Mid-mode...
We report on first commissioning results of the DRACO Petawatt ultra-short pulse laser system implemented at ELBE center for high power radiation sources Helmholtz-Zentrum Dresden-Rossendorf. Key parameters essential efficient and reproducible performance plasma accelerators are presented discussed with demonstration 40 MeV proton acceleration under TNSA conditions as well peaked electron spectra unprecedented bunch charge in 0.5 nC range.
Inverse bremsstrahlung absorption was measured based on transmission through a finite-length plasma that thoroughly characterized using spatially resolved Thomson scattering. Expected then calculated the diagnosed conditions while varying model components. To match data, it is necessary to account for (i) Langdon effect; (ii) laser-frequency (rather than plasma-frequency) dependence in Coulomb logarithm, as typical of theories but not transport theories; and (iii) correction due ion...
The first inertial confinement fusion implosion experiments with equimolar deuterium-tritium thermonuclear fuel have been performed on the National Ignition Facility. These use 0.17 mg of potential for ignition and significant yield conditions. has fielded as a cryogenic layer inside spherical plastic capsule that is mounted in center cylindrical gold hohlraum. Heating hohlraum 192 laser beams total energy 1.6 MJ produces soft x-ray field 300 eV temperature. ablation pressure produced by...
The full scale modeling of power transfer between laser beams crossing in plasmas is presented. A new model was developed, allowing calculations the propagation and coupling pairs with their associated plasma wave three dimensions. complete set beam smoothing techniques used ignition experiments modeled effects on crossed-beam energy are investigated. shift wavelength can move instability or out resonance hence allows tuning transfer. effective pointing symmetry have been Several designs...
When intense laser beams overlap in plasmas, the refractive index modulation created by beat wave via ponderomotive force can lead to optical mixing phenomena similar those used crystals and photorefractive materials. A new comprehensive analytical description of modification polarization state crossing at arbitrary angles a plasma is presented. It shown that laser-plasma system be provide full control separate “probe” beam; simple estimates practical considerations are provided for design...
Backscattered light via laser-plasma instabilities has been measured in early NIF hohlraum experiments on two beam quads using a suite of detectors. A full aperture backscatter system and near imager (NBI) instrument separately measure the stimulated Brillouin Raman scattered light. Both instruments work conjunction to determine total backscattered power an accuracy ∼15%. In order achieve we have added time-resolution NBI for first time. This capability provides temporally resolved spatial...