B. J. MacGowan
A5088101885- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- Laser-Matter Interactions and Applications
- Laser Design and Applications
- High-pressure geophysics and materials
- Nuclear Physics and Applications
- Advanced X-ray Imaging Techniques
- Combustion and Detonation Processes
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Optical Sensing Technologies
- Solid State Laser Technologies
- Amphibian and Reptile Biology
- Cold Fusion and Nuclear Reactions
- Magnetic confinement fusion research
- Diamond and Carbon-based Materials Research
- Spectroscopy and Laser Applications
- Ocular and Laser Science Research
- Traumatic Ocular and Foreign Body Injuries
- Cold Atom Physics and Bose-Einstein Condensates
- Turtle Biology and Conservation
- Wildlife Ecology and Conservation
- Optical Systems and Laser Technology
- Fusion materials and technologies
- Rangeland and Wildlife Management
Lawrence Livermore National Laboratory
2015-2024
Lawrence Livermore National Security
1988-2024
General Atomics (United States)
2010-2022
Massachusetts Institute of Technology
2013-2021
Fusion Academy
2014-2021
Fusion (United States)
2014-2021
Energetics (United States)
2016-2020
University of Rochester
1990-2020
Purdue University West Lafayette
2012-2018
Los Alamos National Laboratory
1998-2018
We report observations of amplified spontaneous emission at soft x-ray wavelengths. An optical laser ionized thin foils selenium to produce a population inversion the $2{p}^{5}3p$ and $2{p}^{5}3s$ levels neonlike ion. Using three time-resolved, spectroscopic measurements we demonstrated gain-length products up 6.5 gain coefficients 5.5\ifmmode\pm\else\textpm\fi{}1.0 ${\mathrm{cm}}^{\ensuremath{-}1}$ for $J=2 \mathrm{to} 1$ lines 206.3 209.6 \AA{}. also observed considerable amplification...
Point design targets have been specified for the initial ignition campaign on National Ignition Facility [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)]. The contain D-T fusion fuel in an ablator of either CH with Ge doping, or Be Cu. These shells are imploded a U Au hohlraum peak radiation temperature set between 270 300 eV. Considerations determining point include laser-plasma interactions, hydrodynamic instabilities, laser operations, target fabrication....
We describe a design for producing soft x-ray laser via $3p\ensuremath{-}3s$ transitions in Ne-like selenium (wavelength of about 200 \AA{}). A 0.53-\ensuremath{\mu} m laser, focused 1.2\ifmmode\times\else\texttimes\fi{}0.02-cm spot to \ensuremath{\sim} 5\ifmmode\times\else\texttimes\fi{}${10}^{13}$ W/${\mathrm{cm}}^{2}$, heats and burns through thin foil Se. Besides ionizing the Se state, explodes foil, creating region uniform electron density. This allows propagation x rays down 1-cm-long...
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...
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...
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.
The possibility of imploding small capsules to produce mini-fusion explosions was explored soon after the first thermonuclear in early 1950s. Various technologies have been pursued achieve focused power and energy required for laboratory-scale fusion. Each technology has its own challenges. For example, electron ion beams can deliver large amounts but must contend with Coulomb repulsion forces that make focusing these a daunting challenge. demonstration laser 1960 provided new option. Energy...
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...
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...
An inertial fusion implosion on the National Ignition Facility, conducted August 8, 2021 (N210808), recently produced more than a megajoule of yield and passed Lawson's criterion for ignition [Phys. Rev. Lett. 129, 075001 (2022)]. We describe experimental improvements that enabled N210808 present first measurements from an igniting plasma in laboratory. metrics like product hot-spot energy pressure squared, absence self-heating, increased by ∼35%, leading to record values enhancement...
We present the design of first igniting fusion plasma in laboratory by Lawson's criterion that produced 1.37 MJ energy, Hybrid-E experiment N210808 (August 8, 2021) [Phys. Rev. Lett. 129, 075001 (2022)10.1103/PhysRevLett.129.075001]. This uses indirect drive inertial confinement approach to heat and compress a central "hot spot" deuterium-tritium (DT) fuel using surrounding dense DT piston. Ignition occurs when heating from absorption α particles created process overcomes loss mechanisms...
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...
An indirect-drive inertial fusion experiment on the National Ignition Facility was driven using 2.05 MJ of laser light at a wavelength 351 nm and produced 3.1±0.16 total yield, producing target gain G=1.5±0.1 exceeding unity for first time in laboratory [Phys. Rev. E 109, 025204 (2024)10.1103/PhysRevE.109.025204]. Herein we describe experimental evidence increased drive capsule additional energy control over known degradation mechanisms, which are critical to achieving high performance....
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...
Ignition requires precisely controlled, high convergence implosions to assemble a dense shell of deuterium-tritium (DT) fuel with ρR>∼1 g/cm2 surrounding 10 keV hot spot ρR ∼ 0.3 g/cm2. A working definition ignition has been yield ∼1 MJ. At this the α-particle energy deposited in would have ∼200 kJ, which is already ∼10 × more than kinetic typical implosion. The National Campaign includes low dudded layers study and optimize hydrodynamic assembly diagnostics rich environment. mixture...
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...
After every other failure mode has been considered, in the end, high-performance limit of all lasers is set by optical damage. The demands inertial confinement fusion (ICF) pushed designed as ICF drivers into this from their very earliest days. first were small, and pulses short. Their goal was to provide much power target possible. Typically, they faced damage due high intensity on optics. As requests for higher laser energy, longer pulse lengths, better symmetry appeared, new kinds also...
The National Ignition Facility (NIF) at Lawrence Livermore Laboratory (LLNL) houses the world's largest laser system, composed of 192 individual, 40-cm-aperture beamlines. NIF routinely operates ultraviolet (UV) fluences above 8 J/cm2, more than twice (3ω only) damage threshold commercially available UV-grade fused silica. is able to maintain such high fluence operation by using an optics recycling loop strategy. Successful relies on a number technologies specifically developed for NIF. One...
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,...
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...
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 National Ignition Facility (NIF) laser is the culmination of more than 40 years work at Lawrence Livermore Laboratory dedicated to delivery systems capable driving experiments for study high-energy-density physics. Although NIF was designed support a number missions, it clear from beginning that its biggest challenge meet requirements pursuit inertial confinement fusion. Meeting Project Completion Criteria in 2009 and Campaign (NIC) 2012 included meeting Functional Requirements Primary...
Inertial confinement fusion implosions must achieve high in-flight shell velocity, sufficient energy coupling between the hot spot and imploding shell, areal density (ρR=∫ρdr) at stagnation. Asymmetries in ρR degrade of kinetic to reduce that energy. We present first evidence nonuniformity ablator thickness (∼0.5% total thickness) high-density carbon experiments is a significant cause for observed 3D asymmetries National Ignition Facility. These shell-thickness nonuniformities have...