A5003931166- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- High-pressure geophysics and materials
- Nuclear Physics and Applications
- Laser-Matter Interactions and Applications
- Combustion and Detonation Processes
- Atomic and Molecular Physics
- Energetic Materials and Combustion
- Laser Design and Applications
- Ion-surface interactions and analysis
- Cold Fusion and Nuclear Reactions
- Advanced X-ray Imaging Techniques
- Magnetic confinement fusion research
- X-ray Spectroscopy and Fluorescence Analysis
- Fusion materials and technologies
- Electron and X-Ray Spectroscopy Techniques
- Laser Material Processing Techniques
- Radiation Detection and Scintillator Technologies
- Quantum Chromodynamics and Particle Interactions
- Planetary Science and Exploration
- Particle physics theoretical and experimental studies
- Advanced Optical Sensing Technologies
- Nuclear reactor physics and engineering
- Engineering and Material Science Research
- Advanced X-ray and CT Imaging
Lawrence Livermore National Laboratory
2016-2025
Commercial Aircraft Corporation of China (China)
2024
Massachusetts Institute of Technology
2009-2023
Rutherford Appleton Laboratory
2014-2023
General Atomics (United States)
2009-2023
The University of Texas at Austin
2023
University of California, Los Angeles
2023
Florida Agricultural and Mechanical University
2023
Schloss Dagstuhl – Leibniz Center for Informatics
2023
Purple Mountain Observatory
2011-2023
Abstract Obtaining a burning plasma is critical step towards self-sustaining fusion energy 1 . A one in which the reactions themselves are primary source of heating plasma, necessary to sustain and propagate burn, enabling high gain. After decades research, here we achieve burning-plasma state laboratory. These experiments were conducted at US National Ignition Facility, laser facility delivering up 1.9 megajoules pulses with peak powers 500 terawatts. We use lasers generate X-rays radiation...
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...
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...
Deuterium-tritium inertial confinement fusion implosion experiments on the National Ignition Facility have demonstrated yields ranging from 0.8 to 7×10(14), and record fuel areal densities of 0.7 1.3 g/cm2. These implosions use hohlraums irradiated with shaped laser pulses 1.5-1.9 MJ energy. The peak power duration at were varied, as capsule ablator dopant concentrations shell thicknesses. We quantify level hydrodynamic instability mix into hot spot measured elevated absolute x-ray emission...
This Letter reports on a series of high-adiabat implosions cryogenic layered deuterium-tritium (DT) capsules indirectly driven by ``high-foot'' laser drive pulse at the National Ignition Facility. High-foot have high ablation velocities and large density gradient scale lengths are more resistant to ablation-front Rayleigh-Taylor instability induced mixing ablator material into DT hot spot. Indeed, observed spot mix in these was low measured neutron yields were typically 50% (or higher)...
The National Ignition Campaign's [M. J. Edwards et al., Phys. Plasmas 20, 070501 (2013)] point design implosion has achieved DT neutron yields of $7.5\ifmmode\times\else\texttimes\fi{}1{0}^{14}$ neutrons, inferred stagnation pressures 103 Gbar, and areal densities ($\ensuremath{\rho}R$) $0.90\text{ }\text{ }\mathrm{g}/\mathrm{cm}{}^{2}$ (shot N111215), values that are lower than 1D expectations by factors $10\ifmmode\times\else\texttimes\fi{}$, $3.3\ifmmode\times\else\texttimes\fi{}$,...
Abstract In a burning plasma state 1–7 , alpha particles from deuterium–tritium fusion reactions redeposit their energy and are the dominant source of heating. This has recently been achieved at US National Ignition Facility 8 using indirect-drive inertial-confinement fusion. Our experiments use laser-generated radiation-filled cavity (a hohlraum) to spherically implode capsules containing deuterium tritium fuel in central hot spot where occur. We have developed more efficient hohlraums...
Metal foil targets were irradiated with 1 mum wavelength (lambda) laser pulses of 5 ps duration and focused intensities (I) up to 4x10;{19} W cm;{-2}, giving values both Ilambda;{2} pulse comparable those required for fast ignition inertial fusion. The divergence the electrons accelerated into target was determined from spatially resolved measurements x-ray K_{alpha} emission transverse probing plasma formed on back foils. Comparison other published data shows that it increases is...
First measurements of the in-flight shape imploding inertial confinement fusion (ICF) capsules at National Ignition Facility (NIF) were obtained by using two-dimensional x-ray radiography. The sequence area-backlit, time-gated pinhole images is analyzed for implosion velocity, low-mode and density asymmetries, absolute offset center-of-mass velocity capsule shell. shell often observed to be asymmetric even when concomitant core self-emission round. $\mathrm{A}\ensuremath{\sim}15\text{...
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...
Mixing of plastic ablator material, doped with Cu and Ge dopants, deep into the hot spot ignition-scale inertial confinement fusion implosions by hydrodynamic instabilities is diagnosed x-ray spectroscopy on National Ignition Facility. The amount hot-spot mix mass determined from absolute brightness emergent K-shell emission. dopants placed at different radial locations in show ablation-front instability primarily responsible for mix. Low neutron yields between 34(-13,+50) ng 4000(-2970,+17...
High Density Carbon (HDC) is a leading candidate as an ablator material for Inertial Confinement Fusion (ICF) capsules in x-ray (indirect) drive implosions. HDC has higher density (3.5 g/cc) than plastic (CH, 1 g/cc), which results thinner with larger inner radius given capsule scale. This leads to absorption and shorter laser pulses compared equivalent CH designs. paper will describe series of experiments carried out examine the feasibility using both gas filled hohlraums lower density,...
DT neutron yield (Y(n)), ion temperature (T(i)), and down-scatter ratio (dsr) determined from measured spectra are essential metrics for diagnosing the performance of inertial confinement fusion (ICF) implosions at National Ignition Facility (NIF). A suite neutron-time-of-flight (nTOF) spectrometers a magnetic recoil spectrometer (MRS) have been implemented in different locations around NIF target chamber, providing good implosion coverage complementarity required reliable measurements Y(n),...
Measurements have been made of the in-flight dynamics imploding capsules indirectly driven by laser energies 1–1.7 MJ at National Ignition Facility [Miller et al., Nucl. Fusion 44, 228 (2004)]. These experiments were part Campaign [Landen Phys. Plasmas 18, 051002 (2011)] to iteratively optimize inputs required achieve thermonuclear ignition in laboratory. Using gated or streaked hard x-ray radiography, a suite ablator performance parameters, including time-resolved radius, velocity, mass,...
Recent experiments on the National Ignition Facility [M. J. Edwards et al., Phys. Plasmas 20, 070501 (2013)] demonstrate that utilizing a near-vacuum hohlraum (low pressure gas-filled) is viable option for high convergence cryogenic deuterium-tritium (DT) layered capsule implosions. This made possible by using dense ablator (high-density carbon), which shortens drive duration needed to achieve convergence: measured 40% higher efficiency than typical gas-filled hohlraums, requires less laser...
Ignition of an inertial confinement fusion (ICF) target depends on the formation a central hot spot with sufficient temperature and areal density. Radiative conductive losses from can be enhanced by hydrodynamic instabilities. The concentric spherical layers current National Facility (NIF) ignition targets consist plastic ablator surrounding thin shell cryogenic thermonuclear fuel (i.e., hydrogen isotopes), vapor filling interior volume [S. W. Haan et al., Phys. Plasmas 18, 051001 (2011)]....
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...
Detailed measurements of the electron densities, temperatures, and ionization states compressed CH shells approaching pressures 50 Mbar are achieved with spectrally resolved x-ray scattering. Laser-produced 9 keV x-rays probe plasma during transient state three-shock coalescence. High signal-to-noise scattering spectra show direct evidence continuum depression in highly degenerate warm dense matter densities ne>1024 cm-3. The measured temperatures agree well radiation-hydrodynamic modeling...
We report on the first layered deuterium-tritium (DT) capsule implosions indirectly driven by a "high-foot" laser pulse that were fielded in depleted uranium hohlraums at National Ignition Facility. Recently, high-foot have demonstrated improved resistance to ablation-front Rayleigh-Taylor instability induced mixing of ablator material into DT hot spot [Hurricane et al., Nature (London) 506, 343 (2014)]. Uranium provide higher albedo and thus an increased drive equivalent additional 25 TW...
We report on the dynamics of ultrafast heating in cryogenic hydrogen initiated by a ≲300 fs, 92 eV free electron laser x-ray burst. The rise scattering amplitude from second pulse probes transition dense molecular to nearly uncorrelated plasmalike structure, indicating an electron-ion equilibration time ∼0.9 ps. agrees with radiation hydrodynamics simulations based conductivity model for partially ionized plasma that is validated two-temperature density-functional theory.
The Bigfoot approach is to intentionally trade off high convergence, and therefore areal-density, in favor of implosion velocity good coupling between the laser, hohlraum, shell, hotspot. This results a short laser pulse that improves hohlraum symmetry predictability, while reduced compression reduces hydrodynamic instability growth. thus far include demonstrated low-mode control at two different geometries (5.75 mm 5.4 diameters) target scales (5.4 6.0 spanning 300–405 TW power 0.8–1.6 MJ...
The neutron imaging system at the National Ignition Facility (NIF) is an important diagnostic tool for measuring two-dimensional size and shape of neutrons produced in burning deuterium-tritium plasma during ignition stage inertial confinement fusion (ICF) implosions NIF. Since source small (∼100 μm) are deeply penetrating (>3 cm) all materials, apertures used to achieve desired 10-μm resolution 20-cm long, single-sided tapers gold. These apertures, which have triangular cross...