A5074127757- Laser-induced spectroscopy and plasma
- Laser-Plasma Interactions and Diagnostics
- Ionosphere and magnetosphere dynamics
- Magnetic confinement fusion research
- Solar and Space Plasma Dynamics
- Atomic and Molecular Physics
- Astro and Planetary Science
- Space Satellite Systems and Control
- Geomagnetism and Paleomagnetism Studies
- Laser Design and Applications
- High-pressure geophysics and materials
- Plasma Diagnostics and Applications
- Astrophysics and Cosmic Phenomena
- Laser Material Processing Techniques
- Diamond and Carbon-based Materials Research
- Nuclear Physics and Applications
- Gamma-ray bursts and supernovae
- Dust and Plasma Wave Phenomena
- Particle Dynamics in Fluid Flows
- Planetary Science and Exploration
- Magnetic Field Sensors Techniques
- Surface Roughness and Optical Measurements
- Gas Dynamics and Kinetic Theory
- Ion-surface interactions and analysis
- Geophysics and Gravity Measurements
University of California, Los Angeles
2014-2025
Princeton University
2017-2024
University of Rome Tor Vergata
2022
University of Rochester
2021
Energetics (United States)
2021
Los Alamos National Laboratory
2017-2020
Princeton Plasma Physics Laboratory
2020
University of New Hampshire
2020
Lawrence Livermore National Laboratory
2017
University of Louisville Hospital
2012
Probing of electromagnetic fields in high-energy-density experiments is key to understanding questions fusion processes such as how the are compressed, diffuse through plasma, and can seed instabilities. Many kinetic studied, including collisionless shocks, filamentary instabilities, jets, magnetic reconnection, turbulence, all depend on field structure. In this review, an overview experimental techniques underpinning theoretical principles modeling proton-based imaging presented, followed...
The Mars Color Imager (MARCI) instrument aboard the NASA Reconnaissance Orbiter spacecraft is a wide‐angle, multispectral Charge‐Coupled Device (CCD) “push frame” imaging camera designed to provide frequent, synoptic‐scale color of Martian atmosphere and surface. MARCI uses 1024 × pixel interline transfer CCD detector that has seven narrowband interference filters bonded directly CCD. Five are in visible short‐wave near‐infrared wavelength range (437, 546, 604, 653, 718 nm) two ultraviolet...
A three-axis, 2.5 mm overall diameter differential magnetic probe (also known as B-dot probe) is discussed in detail from its design and construction to calibration use diagnostic of fast transient effects exploding plasmas. method presented a means reduce stray pickup, eliminate electrostatic physical size, increase signals while maintaining high bandwidth. The probe’s frequency response measured 10 kHz 50 MHz using the compared theory. effect self-induction first order correction...
Shocks act to convert incoming supersonic flows heat, and in collisionless plasmas the shock layer forms on kinetic plasma scales through collective electromagnetic effects. These shocks have been observed many space astrophysical systems [Smith 1975, Smith 1980, Burlaga 2008, Sulaiman 2015], are believed accelerate particles, including cosmic rays, extremely high energies [Kazanas 1986, Loeb 2000, Bamba 2003, Masters 2013, Ackermann 2013]. Of particular importance class of high-Mach number,...
Abstract We report the first measurements of formation and structure a magnetized collisionless shock by laser‐driven magnetic piston in current‐free laboratory plasma. This new class experiments combines high‐energy laser system large plasma to transfer energy from plume ambient ions through coupling, until self‐sustained M A ∼ 2 magnetosonic separates piston. The is highly magnetized, current free, enough (17 m × 0.6 m) support Alfvén waves. Magnetic field evolution are consistent with...
We present the first laboratory observations of time-resolved electron and ion velocity distributions in magnetized collisionless shock precursors. Thomson scattering a probe laser beam was used to observe interaction laser-driven, supersonic piston plasma expanding through an ambient external magnetic field. From Thomson-scattered spectra we measure profiles density, temperature, flow speed, as well spatially resolved fields from proton radiography. direct evidence coupling between plasmas,...
The dynamics of an exploding laser-produced plasma in a large ambient magneto-plasma was investigated with magnetic flux probes and Langmuir probes. Debris-ions expanding at super-Alfvénic velocity (up to MA=1.5) expel the field, creating (>20 cm) diamagnetic cavity. We observe field compression up B/B0=1.5 as well localized electron heating edge bubble. Two-dimensional hybrid simulations reproduce these measurements show that majority ions are energized by piston swept outside bubble...
We present experiments on the Trident laser facility at Los Alamos National Laboratory which demonstrate key elements in production of laser-driven, magnetized, laboratory-scaled astrophysical collisionless shocks. These include creation a novel magnetic piston to couple energy background plasma and generation shock precursor. also observe evidence decoupling between laser-driven fast ion population plasma, contrast coupling laser-ablated slow ions with through piston. 2D hybrid simulations...
Strongly localized, propagating plasma density structures that are capable of crossing magnetic field lines known as "blobs." Here we demonstrate a novel mechanism for the formation and propagation an ion gyroradius-scale blob-cavity structure at interface between super-Alfvénic laser-produced (LPP) ambient magnetized plasma. The LPP self-focuses along edge diamagnetic cavity which results in dense, jetlike compared to ballistic motion. This collimated flow couples momentum through...
MagNetUS is a network of scientists and research groups that coordinates advocates for fundamental magnetized plasma in the USA. Its primary goal to bring together broad community researchers experimental numerical tools they use order facilitate sharing ideas, resources common tasks. Discussed here are motivation goals this details its formation, history structure. An overview associated facilities projects provided, along with examples scientific topics investigated therein. Finally,...
We have commissioned a high-energy glass-laser at the Large Plasma Device (LAPD) to study interaction of dense laser-produced plasma with large (17 m) magnetized plasma. First experiments an energy laser blow-off order magnitude higher than previous work (Gekelman et al. in J. Geophys. Res. 108(A7):1281, 2003) produced amplitude Alfvén waves (δ B ⊥ /B 0≈15%). will discuss potential this facility for collisionless laboratory astrophysics experiments.
A kilojoule-class laser (Raptor) has recently been activated at the Phoenix-laser-facility University of California Los Angeles (UCLA) for an experimental program on laboratory astrophysics in conjunction with Large Plasma Device (LAPD). The unique combination a high-energy system and 18 meter long, highly-magnetized but current-free plasma will support new class physics experiments, including first simulations quasi-parallel collisionless shocks, experiments magnetic reconnection, or...
Collisionless shocks are common phenomena in space and astrophysical systems, many cases, the can be modeled as result of expansion a magnetic piston though magnetized ambient plasma. Only recently, however, have laser facilities diagnostic capabilities evolved sufficiently to allow detailed study laboratory microphysics piston-driven shocks. We review experiments on collisionless driven by laser-produced undertaken with Phoenix Large Plasma Device at University California, Los Angeles. The...
Collisionless shocks are ubiquitous in space and astrophysical systems, the class of supercritical is particular importance due to their role accelerating particles high energies. While these have been traditionally studied by spacecraft remote sensing observations, laboratory experiments can provide reproducible multi-dimensional datasets that a complementary understanding underlying microphysics. We present undertaken on OMEGA EP laser facilities show formation evolution high-Mach number...
Experiments, analytic modeling, and numerical simulations are presented to characterize carbon plasmas produced by high-intensity (109−1013 W cm−2) lasers relevant experimental laboratory astrophysics. In the large-scale limit, results agree well with a self-similar isentropic, adiabatic fluid model. Laser-target simulations, however, show small-scale structure in velocity distribution of different ion species, which is also seen experiments. These distributions indicate that most plasma...
Magnetized collisionless shocks are common in astrophysical systems, and scaled versions can be created laboratory experiments by utilizing laser-driven piston plasmas to create these a magnetized background plasma. A key parameter for is the angle θB between shock propagation direction magnetic field. We performed quasi-1D piston-driven simulations explore formation, evolution, observables relevant range of angles θB=90° θB=30°. Our results show that spatial temporal scales formation all...
Magnetic fields generated from a laser-foil interaction are measured with high fidelity using proton radiography scheme x-ray fiducials. In contrast to prior findings under similar experimental conditions, this technique reveals the self-generated, Biermann-battery extend beyond edge of expanding plasma plume radius over 3.5 mm by <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>t</a:mi></a:math>=<b:math...
Two-dimensional hybrid simulations of perpendicular collisionless shocks are modeled after potential laboratory conditions that attainable in the LArge Plasma Device (LAPD) at University California, Los Angeles Basic Science Facility. The kJ class 1053 nm Nd:Glass Raptor laser will be used to ablate carbon targets LAPD with on-target energies 100-500 J. ablated debris ions expand into ambient, partially ionized hydrogen or helium. A parameter study is performed via simulation determine...
The interaction of a laser-driven super-Alfvénic magnetic piston with large, preformed magnetized ambient plasma has been studied by utilizing unique experimental platform that couples the Raptor kJ-class laser system [Niemann et al., J. Instrum. 7, P03010 (2012)] to Large Plasma Device [Gekelman Rev. Sci. 62, 2875 (1991)] at University California, Los Angeles. This provides conditions relevance space and astrophysical collisionless shocks and, in particular, allows detailed study...
Recent experiments at the University of California, Los Angeles have successfully generated subcritical magnetized collisionless shocks, allowing new laboratory studies shock formation relevant to space shocks. The characteristics these shocks are compared with data in which no or a pre-shock formed. results consistent theory and 2D hybrid simulations indicate that observed shock-like structures can be organized into distinct regimes by coupling strength. With additional on early time...
Laboratory laser experiments offer a novel approach to studying magnetized collisionless shocks, and common method in recent is drive shocks using laser-ablated piston plasma. However, current experimental capabilities are still limited spatiotemporal scales on the order of shock formation, making it challenging distinguish dynamics. We present quasi-1D particle-in-cell simulations piston-driven, formation code PSC, which includes model laser-driven plasmas that can be well-matched...
Magnetospheres are a ubiquitous feature of magnetized bodies embedded in plasma flow. While large planetary magnetospheres have been studied for decades by spacecraft, ion-scale “mini” can provide unique environment to study kinetic-scale, collisionless physics the laboratory help validate models larger systems. In this work, we present preliminary experiments performed on high-repetition-rate platform developed Large Plasma Device at University California, Los Angeles. The utilize laser...
Laser-produced plasmas are often used as bright x-ray backlighters for time-resolved plasma diagnostics, but such simultaneously generate damaging electromagnetic pulse (EMP). A laser-driven Ar gas jet source has been measured with magnetic flux B-dot probes to produce 20 times ±37% less integrated EMP in the 0.5–2.5 GHz band than a solid chlorinated plastic foil, while retaining 85% of laser ≈3 keV conversion efficiency. These results important future backlighter development, since...
We present a new experimental platform for studying laboratory astrophysics that combines high-intensity, high-repetition-rate laser with the Large Plasma Device at University of California, Los Angeles. To demonstrate utility this platform, we show first results volumetric, highly repeatable magnetic field and electrostatic potential measurements, along derived quantities electric field, charge density current density, interaction between super-Alfvénic laser-produced plasma an ambient,...