A5044763884- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- Laser Design and Applications
- Plasma Diagnostics and Applications
- Magnetic confinement fusion research
- Laser-Matter Interactions and Applications
- Combustion and Detonation Processes
- Nuclear Physics and Applications
- Pulsed Power Technology Applications
- Ion-surface interactions and analysis
- Gas Dynamics and Kinetic Theory
- Ionosphere and magnetosphere dynamics
- Gyrotron and Vacuum Electronics Research
- Solid State Laser Technologies
- X-ray Spectroscopy and Fluorescence Analysis
- Particle accelerators and beam dynamics
- Plasma Applications and Diagnostics
- Energetic Materials and Combustion
- Plasma and Flow Control in Aerodynamics
- Electrostatic Discharge in Electronics
- High-pressure geophysics and materials
- Electromagnetic Launch and Propulsion Technology
- Metal and Thin Film Mechanics
- Fluid Dynamics and Turbulent Flows
United States Naval Research Laboratory
2015-2024
Sandia National Laboratories
2009-2022
Neurobehavioral Research Laboratory and Clinic
2010-2021
Naval Research Laboratory Plasma Physics Division
1999-2020
Syntek Technologies (United States)
2019
University of Nevada, Reno
2011-2014
Engility (United States)
2014
Laboratoire de Physique des Plasmas
2014
École Polytechnique
2014
Research Support Instruments (United States)
2009
Pulsed power accelerators compress electrical energy in space and time to provide versatile experimental platforms for high density inertial confinement fusion science. The 80-TW “Z” pulsed facility at Sandia National Laboratories is the largest device world today. Z discharges up 22 MJ of stored its capacitor banks into a current pulse that rises 100 ns peaks as 30 MA low-inductance cylindrical targets. Considerable progress has been made over past 15 years use precision scientific tool....
A coordinated, focused effort is underway to develop Laser Inertial Fusion Energy. The key components are developed in concert with one another and the science engineering issues addressed concurrently. Recent advances include: target designs have been evaluated that show it could be possible achieve high gains (>100) needed for a practical fusion system.These feature low-density CH foam wicked solid DT over-coated thin high-Z layer. These results verified three independent one-dimensional...
We are carrying out a multidisciplinary multi-institutional program to develop the scientific and technical basis for inertial fusion energy (IFE) based on laser drivers direct-drive targets. The key components developed as an integrated system, linking science, technology, final application of 1000-MWe pure-fusion power plant. science technologies here flexible enough be applied other size systems. justification this work is family target designs (simulations) that show direct drive has...
Electron-impact excitation of $\mathrm{Ar}\mathrm{}\mathrm{I}$ from the ground ${3p}^{6}{}^{1}{S}_{0}$ as well two metastable levels ${3p}^{5}4s$ ${(}^{3}{P}_{2}$ and ${}^{3}{P}_{0})$ configuration to all ten ${3p}^{5}4p$ excited are calculated in distorted-wave approximation. Polarization state is explicitly included by adding a polarization potential calculation. Unitarization scattering matrix $\mathbf{S}$ carried out including elastic terms, effects unitarization $\mathrm{LS}$...
The time history of the local ion kinetic energy in a stagnating plasma was determined from Doppler-dominated line shapes. Using independent determination properties for same region, data allowed inferring time-dependent temperature, and discriminating temperature total energy. It is found that throughout most stagnation period thermal constitutes small fraction energy; latter dominated by hydrodynamic motion. Both energies are observed to decrease electron end period. confirmed available at...
The effects of an axial magnetic field on the development instabilities during a z-pinch implosion are studied using 2-D images and interferometry. measurements clearly show mitigation magneto Rayleigh-Taylor with increased magnitude preembedded field. Introducing also gives rise to new structures, indicating interaction between azimuthal fields.
Imploding wire arrays on the 20 MA Z generator have recently provided some of most powerful and energetic laboratory sources multi-keV photons, including ∼375 kJ Al K-shell emission (hν ∼ 1–2 keV), ∼80 stainless steel 5–9 keV) a kJ-level Mo 17 keV). While global implosion dynamics these different are very similar, physical process that dominates from x-ray fall into three broad categories. produce column plasma with densities up to ∼3 × 1021 ions/cm3, where opacity inhibits escape photons....
The fundamental physics of the magnetic field distribution in a plasma implosion with preembedded is investigated within gas-puff $Z$ pinch. Time and space resolved spectroscopy polarized Zeeman effect, applied for first time, reveals impact axial on evolution current driven by pulsed-power generator. measurements show that azimuthal imploding plasma, even presence weak field, substantially smaller than expected from ratio driving to radius. Much flows at large radii through slowly...
In numerous experiments, magnetic energy coupled to strongly radiating Z-pinch plasmas exceeds the thermalized kinetic energy, sometimes by a factor of 2-3. We demonstrate that enhanced coupling may be due buoyancy rise toroidal flux tubes converging axis through unstable pinch plasma. derive an explicit formula for dissipation rate and apply this reconsider old problem power balance in steady-state Z pinch, then analyze new challenge producing K-shell 3 10 keV radiation long-pulse implosions.
A comprehensive gas puff capability is being developed on the Z pulsed power generator. We describe methodology employed for developing a load Z, which combines characterization and modeling of neutral mass flow from supersonic nozzle, numerical implosion this profile, experimental evaluation these magnetic implosions Z. are beginning multiyear science program to study z-pinch physics at high current, starting with an 8-cm diameter double-shell delivers column Ar that imploded by machine's...
The magnetized liner inertial fusion (MagLIF) approach to confinement [Slutz et al., Phys. Plasmas 17, 056303 (2010); Cuneo IEEE Trans. Plasma Sci. 40, 3222 (2012)] involves subsonic/isobaric compression and heating of a deuterium-tritium plasma with frozen-in magnetic flux by heavy cylindrical liner. losses heat from the are thereby determined advection gradient-driven transport processes, such as thermal conductivity, field diffusion, thermomagnetic effects. Theoretical analysis based on...
In numerous experiments, magnetic energy coupled to strongly radiating Z-pinch plasmas exceeds the thermalized kinetic energy, sometimes by a factor of 2–3. An analytical model describing this additional deposition based on concept macroscopic magnetohydrodynamic (MHD) turbulent pinch heating proposed Rudakov and Sudan [Phys. Reports 283, 253 (1997)] is presented. The plasma modeled as foam-like medium saturated with toroidal “magnetic bubbles” produced development surface m=0...
A self-similar solution is derived for a radially imploding cylindrical plasma with an embedded, azimuthal magnetic field. The stagnates through strong, outward propagating shock wave of constant velocity. This analysis extension the classic Noh gasdynamics problem to its ideal magnetohydrodynamics (MHD) counterpart. present exact especially suitable as test MHD codes designed simulate linear Z pinches. To demonstrate application new code verification, simulation results from R-Z version...
Argon gas puffs have produced 330 kJ ± 9% of x-ray radiation above 3 keV photon energy in fast z-pinch implosions, with remarkably reproducible K-shell spectra and power pulses. This reproducibility production is particularly significant light the variations instability evolution observed between experiments. Soft measurements line ratios from a time-resolved spectrum at peak suggest that plasma gradients these high-mass pinches may limit radiating mass, power, yield high-current puffs.
We present here the detailed measurements of radial distribution magnetic field in a gas-puff z-pinch plasma at final stages implosion phase and stagnation. While are chordal, different charge states was utilized to measure locally for certain radii, so that unlike chordal general, obtained with no need Abel inversion data. The measured using Zeeman effect via novel spectroscopic technique, several axial locations, demonstrates striking features such as peak remaining radius much larger than...
Extensive research has been performed to elucidate the transport of electron beam energy from a vacuum diode, through foil support structure (hibachi), and into Electra laser cell. Measurements simulations deposition in cell are reported for various krypton/argon mixtures, gas pressures, thickness material hibachi foil. Two several cathode configurations investigated efficiencies up 75% have achieved with 500 kV, 180 ns full width at half maximum diode pulse. The experimental data compared...
Two sets of z-pinch experiments were recently completed at the Saturn and Phoenix facilities Sandia National Laboratories Naval Surface Warfare Center, respectively, using aluminum wire arrays different array diameters. Measurements total x-ray yield from K shell made. In this paper, a comparison these measurements is made to both theoretical predictions similar set earlier that Double Eagle facility Physics International Company. These three have points agreement with predicted yields each...
High-energy electron beam pumped krypton fluoride (KrF) gas lasers are an attractive choice for inertial fusion energy (IFE). Their short wavelength and demonstrated high uniformity optimizes the laser-target physics, their pulsed power technology scales to a large system. This paper presents principals of this type laser progress toward developing technologies that can meet IFE requirements repetition rate (5 Hz), efficiency (>6%), durability (>3/spl times/10/sup 8/ shots). The Electra at...
Aluminum wire array z pinches imploded on the Z generator are an extremely bright source of 1–2 keV radiation, with close to 400 kJ radiated at photon energies >1 and more than 50 in a single line (Al Ly-α). Opacity plays critical role dynamics K-shell radiation efficiency these pinches. Where significant structure is present stagnated pinch this acts reduce effective opacity system as demonstrated by direct analysis spectra. Analysis time-integrated broadband spectra (0.8–25 keV)...
Double-shell Ar gas puff implosions driven by 16.5 ± 0.5 MA on the Z generator at Sandia National Laboratories are very effective emitters of K-shell radiation (photon energy >3 keV), producing yields 330 9% kJ [B. Jones et al., Phys. Plasmas 22, 020706 (2015)]. Previous simulations and experiments have reported dramatic increases in when adding an on-axis jet to double shell puffs for some configurations. We report a series testing configurations with without guided 3D...
In this paper, we describe the development of electron beam pumped KrF lasers for inertial fusion energy. are an attractive driver fusion, on account their demonstrated very high quality, which is essential reducing imprint in direct drive targets; short wavelength (248 nm), mitigates growth plasma instabilities; and modular architecture, reduces costs. paper present a basic overview laser technology as well current research three key areas: stability transport; kinetics propagation; pulsed...
A computationally efficient method for transporting radiation in multidimensional plasmas has been developed and evaluated. The basis of this is a uniform plasma approximation that allows one to utilize existing escape probability techniques are successfully used one-dimensional (1D) calculations approximately solve the transport problem. This superior diffusion methods because (1) technique insures goes correct optically thin thick limits, (2) effects line absorption due photoexcitations...
The electron deposition in an Ar–Kr–F2 mixture, based on a solution of the Boltzmann equation, is presented. model relevant to electron-beam generated KrF* laser amplifier at atmospheric pressure. Sets cross sections for Ar, Kr, and F2 have been compiled. Calculations performed determine energy distribution function, per electron–ion pair ionization excitation rates. It found that inclusion inner shell subsequent Auger emission are essential matching known results both Wei stopping power...
The difference between the ion thermal and effective temperatures is investigated through simulations of Ne gas puff z-pinch reported by Kroupp et al. [Phys. Rev. Lett. 107, 105001 (2011)]. Calculations are performed using a 2D, radiation-magnetohydrodynamic code with Tabular Collisional-Radiative Equilibrium, namely Mach2-TCRE [Thornhill al., Phys. Plasmas 8, 3480 (2001)]. extensive data set imaging K-shell spectroscopy from experiments provides challenging validation test for simulations....