A5059303060- Laser-Plasma Interactions and Diagnostics
- Laser-induced spectroscopy and plasma
- Magnetic confinement fusion research
- Solar and Space Plasma Dynamics
- Nuclear Physics and Applications
- Ionosphere and magnetosphere dynamics
- High-pressure geophysics and materials
- Gamma-ray bursts and supernovae
- Astro and Planetary Science
- Atomic and Molecular Physics
- Space Satellite Systems and Control
- Radiation Detection and Scintillator Technologies
- Semiconductor Quantum Structures and Devices
- Plasma Diagnostics and Applications
- Plasma and Flow Control in Aerodynamics
- Fusion materials and technologies
- GaN-based semiconductor devices and materials
- Spacecraft and Cryogenic Technologies
- Graphite, nuclear technology, radiation studies
- Stellar, planetary, and galactic studies
- Superconducting Materials and Applications
- Astrophysics and Cosmic Phenomena
- Fluid Dynamics and Turbulent Flows
- Dust and Plasma Wave Phenomena
- X-ray Spectroscopy and Fluorescence Analysis
Massachusetts Institute of Technology
2019-2025
Fusion Academy
2019-2023
Plasma Technology (United States)
2019-2023
Fusion (United States)
2019-2023
Lawrence Livermore National Laboratory
2020
Los Alamos National Laboratory
2019-2020
Rice University
2019-2020
University of Chicago
2019-2020
Applied Energetics (United States)
2020
University of Rochester
2019
Here, we present a Monte Carlo toolkit for validating step range filter (SRF) spectrometer designs. Geant4 is used to transport charged particles through the SRF filters generate synthetic data that include realistic CR-39 effects. Synthetic spectra generated by this method inherently account instrument response and allow quantification of performance before shots. The usefulness demonstrated its application number problems. A new broadband ∼10 MeV wide 3He3He proton spectrum validated, an...
Collisionless shocks are ubiquitous in the Universe as a consequence of supersonic plasma flows sweeping through interstellar and intergalactic media. These cause many observed astrophysical phenomena, but details shock structure behavior remain controversial because lack ways to study them experimentally. Laboratory experiments reported here, with astrophysically relevant parameters, demonstrate for first time formation quasiperpendicular magnetized collisionless shock. In upstream it is...
We present the first local, quantitative measurements of ion current filamentation and magnetic field amplification in interpenetrating plasmas, characterizing dynamics Weibel instability. The interaction a pair laser-generated, counterpropagating, collisionless, supersonic plasma flows is probed using optical Thomson scattering (TS). Analysis TS ion-feature revealed anticorrelated modulations density two streams at spatial scale skin depth c/ω_{pi}=120 μm, correlated modulation current....
Hot-spot shape and electron temperature (Te) are key performance metrics used to assess the efficiency of converting shell kinetic energy into hot-spot thermal in inertial confinement fusion implosions. X-ray penumbral imaging offers a means diagnose Te, where latter can be as surrogate measure ion (Ti) sufficiently equilibrated hot spots. We have implemented new x-ray imager on OMEGA. demonstrate minimal line-of-sight variations inferred Te for set Furthermore, we spatially resolved...
Abstract Using 20 OMEGA laser beams at the Laboratory for Laser Energetics, University of Rochester, to irradiate a flat plastic target in hollow ring configuration, we created supersonic cylindrical stable plasma jets with self-generated megagauss magnetic fields extending out >4 mm. These well-collimated magnetized possess number distinct and novel properties that will allow us study dynamics, physical processes, scaling astrophysical dynamic range exceeding those previous laboratory...
We report a technique of proton deflectometry that uses grid and an in situ reference x-ray image for precise measurements magnetic fields high-energy-density plasmas. A D3He fusion implosion provides bright point source both protons x-rays, which is split into beamlets by grid. The undergo deflections as they propagate through the plasma region interest, whereas x-rays travel along straight lines. image, therefore, zero-deflection image. line-integrated are inferred from shifts between...
The magnetic field produced by planets with active dynamos, like the Earth, can exert sufficient pressure to oppose supersonic stellar wind plasmas, leading formation of a standing bow shock upstream magnetopause, or pressure-balance surface. Scaled laboratory experiments studying interaction an inflowing solar analog strong, external are promising new way study magnetospheric physics and complement existing models, although reaching regimes favorable for magnetized is experimentally...
We report a method to determine the radiative efficiency (RE) of semiconductor by using room-temperature excitation-dependent photoluminescence measurements. Using ABC model for describing recombination carriers, we show that theoretical width RE-versus-carrier-concentration (n) curve is related peak RE. Since normalized external quantum efficiency, EQEnormalized, proportional RE, and square root light-output power, LOP, n, experimentally determined EQEnormalized-versus-n can be used...
It has recently been demonstrated experimentally that a turbulent plasma created by the collision of two inhomogeneous, asymmetric, weakly magnetized, laser-produced jets can generate strong stochastic magnetic fields via small-scale dynamo mechanism, provided Reynolds number is sufficiently large. In this paper, we compare such with one arising from pre-magnetized whose creation identical save for addition external field imposed pulsed generator. We investigate differences between systems...
Two experiments at the OMEGA Laser System used oblique proton radiography to measure magnetic fields in cylindrical implosions with and without an applied axial field. Although goal of both was magnitude compressed field core implosion, this obfuscated by two features coronal plasma produced compression beams: azimuthal self-generated small length scale, high-amplitude structures attributed collisionless effects. In order understand these features, synthetic radiographs are generated using...
A system of x-ray imaging spectrometer (XRIS) has been implemented at the OMEGA Laser Facility and is capable spatially spectrally resolving self-emission from 5 to 40 keV. The consists three independent imagers with nearly orthogonal lines sight for 3D reconstructions emission region. distinct advantage XRIS its large dynamic range, which enabled by use tantalum apertures radii ranging 50 μm 1 mm, magnifications 4 35×, image plates any filtration level. In addition, recording 1-100's images...
This paper presents data from experiments with protons at non-normal incidence to CR-39 nuclear track detectors, analyzing the properties of detection efficiency, proton diameter, contrast, and eccentricity. Understanding response incident an angle is important for designing charged particle detectors inertial confinement fusion (ICF) applications. study considers energies less than 3 MeV. In this regime, 10° has no effect on >85% efficiency preserved up through 25° in range 1.0...
New designs and a new analysis technique have been developed for an existing compact charged-particle spectrometer on the NIF OMEGA. The extends capabilities of this diagnostic to measure arbitrarily shaped ion spectra down 1 MeV with yields as low 106. Three different are provided optimized measurement DD protons, T3He deuterons, 3He3He protons. highly customizable, generalized framework is optimizing design alternative applications. Additionally, understanding detector’s response...
Simultaneously measured DD, DT, and D3He reaction histories are used to probe the impacts of multi-ion physics during shock phase inertial confinement fusion implosions. In these relatively hydrodynamiclike (burn-averaged Knudsen number ⟨NK⟩ ∼0.3) shock-driven implosions, average-ion hydrodynamic DUED simulations able reasonably match burnwidths, nuclear yields, ion temperatures. However, kinetic-ion FPION better simulate timing differences time-resolved rate ratios between reactions....
Fuel–shell mix in kinetic plasma conditions is probed using nuclear and x-ray self-emission shock-driven, D3He-gas-filled inertial confinement fusion implosions. As initial gas fill density decreases, measured yields ion temperatures are lower than expected as compared to radiation-hydrodynamic simulations. Spatially temporally resolved emissions indicate significant mixing at the fuel–shell interface implosions with low density. This observed introduces a substantial amount of shell ions...
Three dimensional FLASH magneto-hydrodynamic modeling is carried out to interpret the OMEGA laser experiments of strongly magnetized, highly collimated jets driven by a ring 20 beams. The predicted optical Thomson scattering spectra and proton images are in good agreement with subset experimental data. Magnetic fields generated via Biermann battery term amplified at boundary between core surrounding jet. simulation predicts multiple axially aligned magnetic flux ropes an alternating poloidal...
Three-dimensional FLASH radiation-magnetohydrodynamics (radiation-MHD) modeling is carried out to study the hydrodynamics and magnetic fields in shock-shear derived platform. Simulations indicate that of tens Tesla can be generated via Biermann battery effect due vortices mix counterpropagating shock-induced shear layer. Synthetic proton radiography simulations using MPRAD synthetic X-ray image SPECT3D are predict observable features diagnostics. Quantifying effects inertial confinement...
Mono-energetic proton radiography is a vital diagnostic for numerous high-energy-density-physics, inertial-confinement-fusion, and laboratory-astrophysics experiments at OMEGA. With large number of campaigns executing hundreds shots, general trends in D3He backlighter performance are statistically observed. Each experimental configuration uses different beams drive symmetry, causing the to perform differently. Here, we analyze impact these variables on overall proton-radiography studies....
Charged particle spectrometry is a critical diagnostic to study inertial-confinement-fusion plasmas and high energy density plasmas. The OMEGA Laser Facility has two fixed magnetic charged spectrometers (CPSs) measure MeV-ions. In situ calibration of these was carried out using 241Am 226Ra alpha emitters. emission spectrum from the sources measured independently surface-barrier detectors (SBDs). dispersion broadening CPS systems were determined by comparing that SBD. method significantly...
Electron-temperature (Te) measurements in implosions provide valuable diagnostic information, as Te is unaffected by residual flows and other non-thermal effects unlike ion temperature inferred from a fusion product spectrum. In OMEGA cryogenic implosions, measurement of Te(t) can be used to investigate related time-resolved hot-spot energy balance. The proposed utilizes five fast-rise (∼15 ps) scintillator channels with distinct x-ray filtering. Titanium stepped aluminum filtering were...
This letter reports the first complete observation of magnetized collisionless shock precursors formed through compression Biermann-battery magnetic fields in laser produced plasmas. At OMEGA, lasers produce a supersonic CH plasma flow which is with fields. The collides an unmagnetized hydrogen gas jet to create precursor. situation where flowing carries field similar Venusian bow shock. Imaging 2$\omega$ Thomson scattering confirms that interaction and shows density temperature jumps....
We report on the design and implementation of a new system used to characterize energy-dependent x-ray transmission curve, Θ(E), through filters in high-energy density physics diagnostics. Using an Amptek X-123-CdTe spectrometer together with partially depleted silicon surface barrier detector, both energy spectrum total emission source have been accurately measured. By coupling these detectors custom PROTO-XRD interchangeable cathodes, accurate characterizations Θ(E) for varying materials...
Magnetic reconnection converts magnetic energy into thermal and kinetic in plasma. Among numerous candidate mechanisms, ion acoustic instabilities driven by the relative drift between ions electrons, or equivalently electric current, have been suggested to play a critical role dissipating collisionless plasmas. However, their existence effectiveness during not well understood due Landau damping difficulties resolving Debye length scale laboratory. Here we report sudden onset of bursts...