S. A. MacLaren
A5017722744- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- High-pressure geophysics and materials
- Laser-Matter Interactions and Applications
- Particle accelerators and beam dynamics
- Magnetic confinement fusion research
- Combustion and Detonation Processes
- Atomic and Molecular Physics
- Nuclear Physics and Applications
- Plasma Diagnostics and Applications
- Energetic Materials and Combustion
- Ion-surface interactions and analysis
- Particle Accelerators and Free-Electron Lasers
- Fluid Dynamics and Turbulent Flows
- Pulsed Power Technology Applications
- Fusion materials and technologies
- Gamma-ray bursts and supernovae
- Computational Fluid Dynamics and Aerodynamics
- Laser Design and Applications
- Cold Fusion and Nuclear Reactions
- Advanced X-ray and CT Imaging
- Gas Dynamics and Kinetic Theory
- Engineering and Material Science Research
- Rocket and propulsion systems research
- High-Velocity Impact and Material Behavior
Lawrence Livermore National Laboratory
2016-2025
Los Alamos National Laboratory
2014-2019
General Atomics (United States)
2017-2019
University of Michigan
2018
Stanford University
2016
University of Rochester
2014
Energetics (United States)
2014
Massachusetts Institute of Technology
2014
Sandia National Laboratories
2007
Lawrence Berkeley National Laboratory
1998-2003
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...
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...
In this work we present the design of first controlled fusion laboratory experiment to reach target gain G>1 N221204 (5 December 2022) [Phys. Rev. Lett. 132, 065102 (2024)], performed at National Ignition Facility, where energy produced (3.15 MJ) exceeded amount laser required drive (2.05 MJ). Following demonstration ignition according Lawson criterion N210808, experiments were impacted by nonideal experimental fielding conditions, such as increased (known) defects that seeded hydrodynamic...
Fusion “scientific breakeven” (i.e., unity target gain <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msub><a:mrow><a:mi>G</a:mi></a:mrow><a:mrow><a:mtext>target</a:mtext></a:mrow></a:msub></a:mrow></a:math>, total fusion energy out <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mo>></c:mo></c:math> laser input) has been achieved for the first time (here, <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"...
As fusion experiments at the National Ignition Facility (NIF) approach and exceed breakeven, energy from burning capsule is predicted to couple gold walls reheat hohlraum. On December 5, 2022, experiment N221204 exceeded target historically achieving 3.15 MJ of 2.05 laser drive; for first time, igniting reheated hohlraum beyond peak laser-driven radiation temperature 313 eV a 350 eV, in less than half nanosecond. This reheating effect has now been unambiguously observed by two independent...
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...
Abstract Energy-transport effects can alter the structure that develops as a supernova evolves into remnant. The Rayleigh–Taylor instability is thought to produce at interface between stellar ejecta and circumstellar matter, based on simple models hydrodynamic simulations. Here we report experimental results from National Ignition Facility explore how large energy fluxes, which are present in supernovae, affect this structure. We observed reduction growth. In analyzing comparison with...
The locus of National Ignition Facility (NIF) inertial confinement fusion (ICF) implosion data, in hot-spot burn-average areal density (ρR) and Brysk temperature (T) space, is shown illustrates that several implosions are nearing a burning plasma state, where α-heating the dominant source heating. A formula for diagnosing using measured/inferred data from ICF experiments given with underlying derivation. Plotting performance against inferred energy key need to maximize delivery an hot-spot....
We present a data-based model for low mode asymmetry in gas-fill hohlraum experiments on the National Ignition Facility {NIF [Moses et al., Fusion Sci. Technol. 69, 1 (2016)]} laser. This is based hypothesis that these fill hohlraums dominated by hydrodynamics of expanding, density, high-Z (gold or uranium) “bubble,” which occurs where intense outer cone laser beams hit wall. developed simple states implosion symmetry becomes more oblate as bubble size large compared to radius capsule...
Abstract Indirect Drive Inertial Confinement Fusion Experiments on the National Ignition Facility (NIF) have achieved a burning plasma state with neutron yields exceeding 170 kJ, roughly 3 times prior record and necessary stage for igniting plasmas. The results are despite multiple sources of degradations that lead to high variability in performance. Results shown here, first time, include an empirical correction factor mode-2 asymmetry regime addition previously determined corrections...
Indirect drive experiments at the National Ignition Facility are designed to achieve fusion by imploding a fuel capsule with x rays from laser-driven hohlraum. Previous have been unable determine whether deficit in measured ablator implosion velocity relative simulations is due inadequate models of hohlraum or physics. ViewFactor allow for first time direct measure x-ray point view. The show 15%--25% and thus explain nearly all disagreement data. In addition, data this open geometry provide...
Herein, recent progress on indirectly-driven inertial confinement fusion (ICF) work at the National Ignition Facility (NIF) is briefly reviewed. An analytic criteria for an ICF burning plasma given and compared to implosion data from NIF. Scaling of key hot-spot performance metrics derived simple physics considerations, including some speculative impacts asymmetry assembly disassembly implosion. A steepest descent solution nonlinear equation pressure peak compression, with full effects...
Advances in hohlraums for inertial confinement fusion at the National Ignition Facility (NIF) were made this past year hohlraum efficiency, dynamic shape control, and hot electron x-ray preheat control. Recent experiments are exploring behavior over a large landscape of parameters by changing shape, gas-fill, laser pulse. Radiation hydrodynamic modeling, which uses measured backscatter, shows that gas-filled utilize between 60% 75% power to match bang-time, whereas near-vacuum 98%....
We describe the overall performance of major indirect-drive inertial confinement fusion campaigns executed at National Ignition Facility. With respect to proximity ignition, we can current experiments both in terms no-burn ignition metrics (metrics based on hydrodynamic targets absence alpha-particle heating) and thermodynamic properties hotspot dense fuel stagnation—in particular, pressure, temperature, areal density. a simple 1D isobaric model derive these quantities from experimental...
A new experimental platform has been developed at the National Ignition Facility (NIF) for studying Rayleigh–Taylor (RT) and Richtmyer–Meshkov (RM) instabilities in a planar geometry high-energy-densities. The uses 60 beams of NIF laser to drive an initially solid shock tube containing pre-machined interface between dense light materials. strong turns target into plasma material boundary fluid with imprinted initial condition. evolves by action RT RM instabilities, growth is imaged backlit...
Abstract Indirect drive converts high power laser light into x-rays using small high- Z cavities called hohlraums. X-rays generated at the hohlraum walls a capsule filled with deuterium–tritium (DT) fuel to fusion conditions. Recent experiments have produced yields exceeding 50 kJ where alpha heating provides ~3× increase in yield over PdV work. Closing gaps toward ignition is challenging, requiring optimization of target/implosions and extract maximum energy. The US program has...
We present direct measurements of electron temperature variations within an inertially confined deuterium-tritium plasma caused by localized mix higher-Z materials into the central hot spot. The data are derived from newly developed differentially filtered penumbral imaging bremsstrahlung continuum emission. Our analysis reveals distinct emitting features in stagnated hot-spot plasma, and we infer spatial temperature: mixed region is...
A multi-laboratory collaborative effort is currently exploring the feasibility of laser direct drive liquid deuterium–tritium (DT) wetted foam inertial confinement fusion concepts being considered for novel neutron sources on National Ignition Facility (NIF) laser. In contrast to indirect approach that recently demonstrated ignition in laboratory, these also offer potential multi-MJ yields but with less damaging drives, improved robustness target and imperfections, enhanced facility fielding...
The x-ray yields from laser-irradiated germanium-doped ultra-low-density aerogel plasmas have been measured in the energy range sub-keV to ≈15 keV at OMEGA laser facility Laboratory for Laser Energetics, University of Rochester. targets’ studied variation target size, density, pulse length, and intensity. For targets that result with electron densities ≈10% critical density 3ω light, one can expect 10–11 J/sr x rays energies above 9 keV, 600–800 below 3.5 keV. In addition spectral yields,...
Detailed radiation hydrodynamic simulations calibrated to experimental data have been used compare the relative strengths and weaknesses of three candidate indirect drive ablator materials now tested at NIF: plastic, high density carbon or diamond, beryllium. We apply a common simulation methodology several currently fielded platforms benchmark model extrapolate designs full NIF envelope on more equal footing. This paper focuses modeling hohlraum energetics which accurately reproduced...
The yield and fuel compression trends for the NIF indirect-drive cryogenically-layered DT implosions is empirically examined across all ablators (CH, C Be) design in-flight adiabats between 1.5 3. Higher observed a lower adiabat. Within adiabat, increases shorter coast but only if have optimized shock timing. sensitivity of to time appears less higher adiabat designs. Across designs ablators, best neutron yields follow same 1D theoretical curve versus peak velocity, normalize by capsule...
We present measurements of ice-ablator mix at stagnation inertially confined, cryogenically layered capsule implosions. An ice layer thickness scan with layers significantly thinner than used in ignition experiments enables us to investigate near the inner ablator interface. Our reveal for first time that majority atomically mixed material is ``dark'' mix. It seeded by interface instability and located relatively cooler, denser region fuel assembly surrounding fusion hot spot. The amount...
In order to understand how close current layered implosions in indirect-drive inertial confinement fusion are ignition, it is necessary measure the level of alpha heating present. To this end, pairs experiments were performed that consisted a low-yield tritium-hydrogen-deuterium (THD) implosion and high-yield deuterium-tritium (DT) validate experimentally simulation-based methods determining yield amplification. The THD capsules designed reduce simultaneously DT neutron (alpha heating)...
We present quantitative motivations and assessments of various proposed ongoing directions to further improving yields target gain igniting indirect-drive implosions at the National Ignition Facility (NIF). These include increasing compression confinement time, hohlraum ablator efficiency, peak power laser energy. 1D hydroscaled simulations, augmented by analytic theory, have been used project yield improvements for each these implosion optimization tracks, normalized best current performing...