A5005983531- Laser-Plasma Interactions and Diagnostics
- High-pressure geophysics and materials
- Laser-induced spectroscopy and plasma
- Advanced X-ray Imaging Techniques
- Atomic and Molecular Physics
- Gamma-ray bursts and supernovae
- Nuclear Physics and Applications
- Geophysics and Gravity Measurements
- Laser-Matter Interactions and Applications
- Astro and Planetary Science
- Electron and X-Ray Spectroscopy Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Iron and Steelmaking Processes
- Gas Dynamics and Kinetic Theory
- Spaceflight effects on biology
- Dynamics and Control of Mechanical Systems
- Advancements in Materials Engineering
- Traumatic Ocular and Foreign Body Injuries
- Cold Fusion and Nuclear Reactions
- Diamond and Carbon-based Materials Research
- Biomedical Ethics and Regulation
- Particle physics theoretical and experimental studies
- Quantum, superfluid, helium dynamics
- Delphi Technique in Research
- Fluid Dynamics and Heat Transfer
University of Rochester
2019-2024
Energetics (United States)
2019-2024
Lawrence Livermore National Laboratory
2016-2024
SLAC National Accelerator Laboratory
2016
We report on the successful operation of a newly developed cryogenic jet target at high intensity laser-irradiation. Using frequency-doubled Titan short pulse laser system Jupiter Laser Facility, Lawrence Livermore National Laboratory, we demonstrate generation pure proton beam with maximum energy 2 MeV. Furthermore, record quasi-monoenergetic peak 1.1 MeV in spectrum emitted forward direction suggesting an alternative acceleration mechanism. solid-density mixed hydrogen-deuterium target,...
High-pressure equation of state and isentropic sound speed data for fluid silicon to pressures 2100 GPa (21 Mbar) are reported. Principal Hugoniot measurements were performed using impedance matching techniques with \ensuremath{\alpha}-quartz as the reference. Sound speeds determined by time correlating imposed shock-velocity perturbations in both sample (Si) reference material (\ensuremath{\alpha}-quartz). A change shock velocity versus particle (${u}_{s}--{u}_{p}$) slope on principal is...
Experiments performed at the Laboratory for Laser Energetics with a continuous-wave (cw) x-ray source and on OMEGA EP Systems [Boehly et al., Opt. Commun. 133, 495 (1997) Waxer Photonics News 16, 30 (2005)] have utilized Fresnel zone plate (FZP) to obtain images spatial resolution as small ∼1.5 μm. Such FZP were obtained charge-coupled device or framing camera energies ranging from 4.5 keV 6.7 using line emission both cw high-intensity, laser-beam–illuminated metal foils. In all cases, test...
We demonstrate the value of inner-shell x-ray absorption spectroscopy for dense-plasma atomic physics and explore coupling between constraint thermodynamic state ionization-potential depression models. Synthetic K-shell spectra are generated along a radius from point-like core analyzed using different Within this synthetic analysis framework, we identify plasma conditions (Te=400 eV, ρ=40g/cm3) accessible by spherical implosions where discriminate models if material temperature is measured...
High-energy-density (HED) experiments in convergent geometry are able to test physical models at pressures beyond hundreds of millions atmospheres. The measurements from these generally highly integrated and require unique analysis techniques procure quantitative information. This work describes a methodology constrain the physics HED by adapting methods common many other fields physics. As an example, mechanical model imploding shell is constrained data thin-shelled direct-drive...
The Guderley model of a self-similar imploding shock based on the group invariance flow equations is powerful tool in understanding behavior converging waves. Two modifications described here improve predictions observable quantities spherical-shock wave experiments. First, noninfinite boundary condition established by isentropic release outer pressure. Second, two-temperature system ions and electrons allows description higher temperatures while conserving energy without perturbing overall...
Convergent high-energy-density (HED) experimental platforms are used to study matter under some of the most extreme conditions that can be produced on Earth, comparable interior stars. There many challenges in using these systems for fundamental measurements currently being addressed by new analysis methods, such as combination a reduced physics model and Bayesian inference, allowing self-consistent inference physical quantities with robust error analysis. These methods simple (as compared...
At the Laboratory for Laser Energetics' Omega Facility, thin plastic shells were directly driven with ∼20 kJ resulting in a time-integrated x-ray yield of ∼1012 ph/eV/sr at 7 keV. Using temporally, spatially, and spectrally discriminating diagnostics, three emission phases identified: corona produced by laser ablation shell, core stagnation, afterglow due to expanding hot material after stagnation. The newly measured account ∼25% total signal produce different time or larger radius than...
Two extended x-ray absorption fine structure flat crystal spectrometers (EFX's) were designed and built for high-resolution spectroscopy over a large energy range with flexible, on-shot dispersion calibration capabilities. The EFX uses silicon [111] in the reflection geometry as dispersive optic covering of 6.3-11.4 keV achieving spectral resolution 4.5 eV source size 50 μm at 7.2 keV. A shot-to-shot configurable filter pack Bayesian inference routine used to constrain relation within ±3 eV....
A technique for measuring residual motion during the stagnation phase of an indirectly driven inertial confinement experiment has been implemented. This method infers a velocity from spatially and temporally resolved images X-ray emission two orthogonal lines sight. work investigates accuracy recovering velocities data. detailed analytical numerical modeling measurement shows that this increases as displacement results increase. For typical experimental configuration, signal-to-noise ratios,...
The ongoing improvement in laser technology and target fabrication is opening new possibilities for diagnostic development. An example x-ray phase-contrast imaging (XPCI), which serves as an advanced laser-driven experiments. In this work, we present the results of XPCI platform that was developed at OMEGA EP Laser-Facility to study multi-Mbar single double shocks produced using a kilojoule driver. Two-dimensional radiation-hydrodynamic simulations agree well with shock progression spherical...
Energy flow and balance in convergent systems beyond petapascal energy densities controls the fate of late-stage stars potential for controlling thermonuclear inertial fusion ignition. Time-resolved x-ray self-emission imaging combined with a Bayesian inference analysis is used to describe information stored rebounding spherical shock at 0.22 PPa (2.2 Gbar or billions atmospheres pressure). This analysis, together simple mechanical model, describes trajectory shell time history pressure...
X-ray radiography is a technique frequently used to diagnose convergent high-energy-density (HED) systems, such as inertial confinement fusion implosion, and provides unique information that not available through self-emission measurements. We investigate the scope limits of using simulation combined with Bayesian inference workflow. The accuracy density reconstruction from simulated radiographs spherical implosions driven 27 kJ laser energy assessed, including increase or decrease in due...
Experiments today can compress solids near isentropically to pressures approaching 100 × 106 atmospheres; however, determining the temperature of such matter remains a major challenge. Extended x-ray absorption fine-structure (EXAFS) spectroscopy is one few techniques sensitive bulk highly compressed solid matter, and validity this measurement relies on constraining local ion structure from EXAFS spectrum. At high-energy-density (HED) conditions, often becomes distorted, which must be...
Laser-driven ion acceleration is of great interest across a range disciplines with potential applications including the fast ignition approach to inertial confinement fusion and proton therapy. The most robust mechanisms studied date however, based on target normal sheath (TNSA), do not satisfy emittance, flux energy requirements for direct applications.