H. G. Rinderknecht
A5059959286- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Nuclear Physics and Applications
- High-pressure geophysics and materials
- Magnetic confinement fusion research
- Atomic and Molecular Physics
- Combustion and Detonation Processes
- Laser-Matter Interactions and Applications
- Cold Fusion and Nuclear Reactions
- Nuclear reactor physics and engineering
- Laser Design and Applications
- Ionosphere and magnetosphere dynamics
- Gamma-ray bursts and supernovae
- Energetic Materials and Combustion
- Fusion materials and technologies
- Atomic and Subatomic Physics Research
- Solar and Space Plasma Dynamics
- Plasma Diagnostics and Applications
- Radioactive contamination and transfer
- Ion-surface interactions and analysis
- Nuclear physics research studies
- Astro and Planetary Science
- Laser Material Processing Techniques
- Superconducting Materials and Applications
- Quantum, superfluid, helium dynamics
University of Rochester
2014-2025
Energetics (United States)
2012-2024
Applied Energetics (United States)
2018-2022
Massachusetts Institute of Technology
2011-2020
Lawrence Livermore National Laboratory
2012-2020
Fusion Academy
2011-2019
Fusion (United States)
2011-2019
Los Alamos National Laboratory
2012-2019
Osaka University
2017-2019
General Atomics (United States)
2012-2019
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...
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,...
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,...
Clear evidence of the transition from hydrodynamiclike to strongly kinetic shock-driven implosions is, for first time, revealed and quantitatively assessed. Implosions with a range initial equimolar DHe3 gas densities show that as density is decreased, hydrodynamic simulations diverge increasingly overpredict observed nuclear yields, factor ∼2 at 3.1 mg/cm3 100 0.14 mg/cm3. (The corresponding Knudsen number, ratio ion mean-free path minimum shell radius, varied 0.3 9; similarly, fusion burn...
A $200\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ radius hot spot at more than 2 keV temperature, $1\text{ }\mathrm{g}/{\mathrm{cm}}^{3}$ density has been achieved on the National Ignition Facility using a near vacuum hohlraum. The implosion exhibits ideal one-dimensional behavior and 99% laser-to-hohlraum coupling. low opacity of remaining shell bang time allows for measurement x-ray emission reflected central shock in deuterium plasma. Comparison with 1D hydrodynamic simulations puts...
Anomalous reduction of the fusion yields by 50% and anomalous scaling burn-averaged ion temperatures with ion-species fraction has been observed for first time in D^{3}He-filled shock-driven inertial confinement implosions. Two kinetic mechanisms are used to explain observations: thermal decoupling D ^{3}He populations diffusive species separation. The insensitivity temperature a varying deuterium is shown be signature shock-heated plasmas. calculated from experimental data demonstrates...
Kinetic physics has the potential to impact performance of indirect-drive inertial confinement fusion (ICF) experiments. Systematic anomalies in National Ignition Facility implosion dataset have been identified which kinetic may play a role, including inferred missing energy hohlraum, drive asymmetry near-vacuum hohlraums, low areal density and high burn-averaged ion temperatures (〈Ti〉) compared with mainline simulations, ratios DD-neutron DT-neutron yields 〈Ti〉. Several components ICF...
Data from nuclear diagnostics present correlated signatures of azimuthal implosion asymmetry in recent indirect-drive inertial confinement fusion (ICF) campaigns performed at the National Ignition Facility (NIF). The mean hot-spot velocity, inferred Doppler shift 14 MeV neutrons produced by deuterium-tritium (DT) fusion, is systematically directed toward one half NIF target chamber, centered on $\ensuremath{\phi}\ensuremath{\approx}70\ifmmode^\circ\else\textdegree\fi{}$. Areal density...
The response of CR-39 nuclear track detector (TasTrak(®)) to protons in the energy range 0.92-9.28 MeV has been studied. Previous studies have extended by examining piece-to-piece variability addition effects etch time and etchant temperature; it is shown that shape curve can vary from piece-to-piece. Effects due age also studied using 5.5 alpha particles over a 5-year period. Track diameters were found degrade with itself rather than tracks, consistent previous utilizing different shorter periods.
Measurements of the $D(d,p)T$ ($dd$) and $T(t,2n)^{4}\mathrm{He}$ ($tt$) reaction yields have been compared with those $D(t,n)^{4}\mathrm{He}$ ($dt$) yield, using deuterium-tritium gas-filled inertial confinement fusion capsule implosions. In these experiments, carried out on OMEGA laser, absolute spectral measurements $dd$ protons $tt$ neutrons were obtained. From measurements, it was concluded that yield is anomalously low high relative to $dt$ an observation we conjecture be caused by a...
A strong nonhydrodynamic mechanism generating atomic fuel-shell mix has been observed in strongly shocked inertial confinement fusion implosions of thin deuterated-plastic shells filled with $^{3}\mathrm{He}$ gas. These were found to produce $\mathrm{D}^{3}\mathrm{He}$-proton shock yields comparable identical a hydroequivalent $50\ensuremath{\mathbin:}50$ $\mathrm{D}^{3}\mathrm{He}$ gas mixture. Standard hydrodynamic mixing cannot explain this observation, as modeling including predicts...
The recent development of petawatt-class lasers with kilojoule-picosecond pulses, such as OMEGA EP [L. Waxer et al., Opt. Photonics News 16, 30 (2005)], provides a new diagnostic capability to study inertial-confinement-fusion (ICF) and high-energy-density (HED) plasmas. Specifically, petawatt pulses have been used backlight implosions energetic proton beams generated through the target normal sheath acceleration (TNSA) mechanism. This allows time-resolved studies mass distribution...
The National Ignition Facility has been used to compress deuterium-tritium an average areal density of ~1.0±0.1 g cm(-2), which is 67% the ignition requirement. These conditions were obtained using 192 laser beams with total energy 1-1.6 MJ and peak power up 420 TW create a hohlraum drive shaped profile, peaking at soft x-ray radiation temperature 275-300 eV. This pulse delivered series shocks that compressed capsule containing cryogenic radius 25-35 μm. Neutron images implosion estimate...
To support direct-drive inertial confinement fusion experiments at the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 43, 2841 (2004)] in its indirect-drive beam configuration, polar-direct-drive (PDD) concept [S. Skupsky et al., Phys. Plasmas 11, 2763 has been proposed. PDD geometry requires direct-drive–specific smoothing, phase plates, repointing NIF beams toward equator to ensure symmetric target irradiation. First study energetics preheat...
The remarkable discovery by the Chandra X-ray observatory that Crab nebula's jet periodically changes direction provides a challenge to our understanding of astrophysical dynamics. It has been suggested this phenomenon may be consequence magnetic fields and magnetohydrodynamic instabilities, but experimental demonstration in controlled laboratory environment remained elusive. Here we report experiments use high-power lasers create plasma can directly compared with through well-defined...
Astrophysical collisionless shocks are common in the universe, occurring supernova remnants, gamma ray bursts, and protostellar jets. They appear colliding plasma flows when mean free path for ion-ion collisions is much larger than system size. It believed that such could be mediated via electromagnetic Weibel instability astrophysical environments without pre-existing magnetic fields. Here, we present laboratory experiments using high-power lasers investigate dynamics of high-Mach-number...
A study of the transition from collisional to collisionless plasma flows has been carried out at National Ignition Facility using high Mach number (M>4) counterstreaming plasmas. In these experiments, CD-CD and CD-CH planar foils separated by 6–10 mm are irradiated with laser energies 250 kJ per foil, generating ∼1000 km/s flows. Varying foil separation distance scales ion density average bulk velocity and, therefore, ion-ion Coulomb mean free path, interaction region midplane. The...
The near vacuum campaign on the National Ignition Facility has concentrated its efforts over last year finding optimum target geometry to drive a symmetric implosion at high convergence ratio (30×). As hohlraum walls are not tamped with gas, is filling gold plasma and challenge resides in depositing enough energy before it fills up. Hohlraum believed cause symmetry swings late pulse that detrimental of hot spot convergence. This paper describes series experiments carried out examine effect...
A simple 3D dynamic model for inertial confinement fusion (ICF) implosions has been developed and used to assess the impacts of low-mode asymmetry, aneurysms mix-induced radiative loss on capsule performance across ICF platforms. The model, while benchmarked against radiation hydrodynamics simulations, benefits from simplicity speed allow rapid assessment possible sources degradation as well help build intuition about relative importance different effects. Degradations in result areal...
The generation of dynamic high energy density plasmas in the pico- to nano-second time domain at high-energy laser facilities affords unprecedented nuclear science research possibilities. At National Ignition Facility (NIF), primary goal inertial confinement fusion has led synergistic development a unique brightness neutron source, sophisticated diagnostic instrumentation, and versatile experimental platforms. These novel capabilities provide new path investigate processes structural effects...
The mode-1 x-ray drive asymmetry of indirect-drive Inertial Confinement Fusion(ICF) implosions at the National Ignition Facility(NIF) has been estimated using a simple static ViewFactor model. model takes as input measured laser performance data in foot and peak, hohlraum configuration, to pointing. These estimates are compared with neutron time-of-flight measurements directionality magnitude resultant hotspot bulk velocity (~20–100 μm/ns) for 39 NIF shots High Density Carbon (HDC) ablators...
Nonuniformities present in the laser illumination and target laser-driven inertial confinement fusion experiments lead to an asymmetric compression of target, resulting inefficient conversion shell kinetic energy thermal hot-spot plasma. In this paper, effects cryogenic deuterium tritium laser-direct-drive implosions are examined using a suite nuclear x-ray diagnostics on OMEGA laser. The neutron-averaged velocity (u→hs) apparent ion temperature (Ti) asymmetry determined from neutron...