M. B. Schneider
A5009227035- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- High-pressure geophysics and materials
- X-ray Spectroscopy and Fluorescence Analysis
- Laser-Matter Interactions and Applications
- Nuclear Physics and Applications
- Magnetic confinement fusion research
- Combustion and Detonation Processes
- Mass Spectrometry Techniques and Applications
- Laser Design and Applications
- Advanced X-ray Imaging Techniques
- Plasma Diagnostics and Applications
- Ion-surface interactions and analysis
- Advanced Optical Sensing Technologies
- Particle accelerators and beam dynamics
- Radiation Detection and Scintillator Technologies
- Advanced X-ray and CT Imaging
- Fusion materials and technologies
- Cold Fusion and Nuclear Reactions
- Computational Fluid Dynamics and Aerodynamics
- Energetic Materials and Combustion
- Spectroscopy and Laser Applications
- Gas Dynamics and Kinetic Theory
- Electron and X-Ray Spectroscopy Techniques
Lawrence Livermore National Laboratory
2016-2025
Princeton University
2021
Colorado State University
2021
Atomic Weapons Establishment
2012-2021
Princeton Plasma Physics Laboratory
2018-2021
University of Rochester
2012-2020
Energetics (United States)
2012-2020
University of Oxford
2020
General Atomics (United States)
2010-2020
Los Alamos National Laboratory
2010-2020
An electron beam ion trap has been built for the production of very-highly-charged ions and study their collisions with electrons. A high density is used to trap, ionize excite spectroscopic measurements. X-ray spectra from neon-like Ba46+ are reported a theory "evaporative" cooling developed explain why these retained in surprisingly long times.
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 turbulent Rayleigh–Taylor instability is investigated over a comprehensive range of fluid density ratio (R)1.3⩽R⩽50 [0.15⩽A=(R−1)/(R+1)⩽0.96] and different acceleration histories g(t) using the Linear Electric Motor. mixing layer diagnosed with backlit photography laser-induced fluorescence. For constant acceleration, bubble (2) spike (1) amplitudes are found to increase as hi=αiAgt2 α2∼0.05±0.005 α1∼α2RDα Dα∼0.33±0.05. temporally varying accelerations Ag(t)>0, this can be...
The time correlation function of the fluctuations in shape large ( ~ 10 03BCm) quasi-spherical hydrated phospholipid membrane vesicles consisting one to several bimolecular layers is measured. These membranes are flaccid, so vesicle area and volume remain constant only contribution energy fluctuating from excess curvature a element. A value for elastic modulus, Kc, obtained mean-square amplitude normal modes using equipartition theorem. An expression found by solving dynamics relaxation...
Richtmyer–Meshkov instability is investigated for negative Atwood number and two-dimensional sinusoidal perturbations by comparing experiments, numerical simulations analytic theories. The experiments were conducted on the NOVA laser with strong radiatively driven shocks Mach numbers greater than 10. Three different hydrodynamics codes (RAGE, PROMETHEUS FronTier) reproduce amplitude evolution gross features in experiment while fine-scale differ techniques. Linearized theories correctly...
Detailed angle and energy resolved measurements of positrons ejected from the back a gold target that was irradiated with an intense picosecond duration laser pulse reveal are in collimated relativistic jet. The laser-positron conversion efficiency is ∼2×10{-4}. jets have ∼20 degree angular divergence distributions quasimonoenergetic 4 to 20 MeV beam temperature ∼1 MeV. sheath electric field on surface shown determine positron energy. distribution controlled by varying field, through...
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...
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,...
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....
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...
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...
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...
Turbulent mixing due to the Rayleigh-Taylor instability is experimentally found vary strongly with temporal acceleration profile g(t). For constant g, bubble amplitude ${\mathit{h}}_{\mathit{b}}$ increases as ${\mathit{gt}}^{2}$ consistent previous results. sustained profiles dg/dt\ensuremath{\ne}0, increases, not displacement Z=\ensuremath{\int}\ensuremath{\int}g dt\ensuremath{'}dt, but length S=0.5 [\ensuremath{\int}\ensuremath{\surd}g dt${]}^{2}$. an impulsive acceleration, minimized...
We report the first measurements of polarization x rays emitted from bound-bound transitions in a highly ionized He-like ion. Polarization was measured for decay to ground state, 1${\mathit{s}}^{2}$ $^{1}$${\mathit{S}}_{0}$, ${\mathrm{Sc}}^{19+}$ levels 1s2p $^{1}$${\mathit{P}}_{1}$, $^{3}$${\mathit{P}}_{2}$, $^{3}$${\mathit{P}}_{1}$, and 1s2s $^{3}$${\mathit{S}}_{1}$. The were made with Electron Beam Ion Trap at two electron-beam energies: 4.36 5.62 keV. lines is strongly influenced by...
The dielectronic recombination excitation function for He-like ${\mathrm{Ni}}^{26+}$ ions has been measured. were created and held in an electron beam ion trap, K x rays detected. Several features observed, including resonant of the transition from to direct at threshold. cross section KLL resonances relative radiative measured, agrees with theoretical sections calculated using multiconfiguration Dirac-fock model.
Three methods for direct measurement of the intensity distribution in laser beams focused by microscope optics to waists submicron width are described and compared. They use scans beam waist with (1) a knife-edge, (2) submicroscopic point fluorescent source, (3) convolution generated photobleached pattern beam. An indirect photographic technique is also evaluated. The found propagate ideally down minimum size usually limited aberrations optics.
Ignition implosions on the National Facility [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)] are underway with goal of compressing deuterium-tritium fuel to a sufficiently high areal density (ρR) sustain self-propagating burn wave required for fusion power gain greater than unity. These driven very carefully tailored sequence four shock waves that must be timed precision keep entropy and adiabat low ρR high. The first series tuning experiments Facility, which use optical diagnostics...
A series of 40 experiments on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] to study energy balance and implosion symmetry in reduced- full-scale ignition hohlraums was shot at energies up 1.3 MJ. This paper reports findings analysis ensemble experimental data obtained that has produced an improved model for simulating hohlraums. Last year first observation a NIF hohlraum transfer between cones beams as function wavelength shift those reported [P....
Achieving inertial confinement fusion ignition requires a symmetric, high velocity implosion. Experiments show that we can reach 95 ± 5% of the required by using 420 TW, 1.6 MJ laser pulse. In addition, experiments with depleted uranium hohlraum an increase in capsule performance which suggests additional 18 5 μm/ns hohlraums over gold hohlraums. Combining these two would give 99 velocity. have ability to tune symmetry crossbeam transfer. We control second Legendre mode (P2) changing...
The effects of laser-plasma interactions (LPI) on the dynamics inertial confinement fusion hohlraums is investigated via a new approach that self-consistently couples reduced LPI models into radiation-hydrodynamics numerical codes. interplay between hydrodynamics and -- specifically stimulated Raman scatter (SRS) crossed-beam energy transfer (CBET) mostly occurs momentum deposition Langmuir ion acoustic waves. This spatially redistributes coupling to target, which affects background plasma...