A5046267243- Magnetic confinement fusion research
- Laser-Plasma Interactions and Diagnostics
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Plasma Diagnostics and Applications
- Laser-induced spectroscopy and plasma
- Astrophysics and Star Formation Studies
- Atomic and Molecular Physics
- Dust and Plasma Wave Phenomena
- Gamma-ray bursts and supernovae
- Pulsed Power Technology Applications
- Seismic Waves and Analysis
- Fluid Dynamics and Turbulent Flows
- Particle accelerators and beam dynamics
- High-pressure geophysics and materials
- Gas Dynamics and Kinetic Theory
- Geophysics and Sensor Technology
- Muon and positron interactions and applications
- Earthquake Detection and Analysis
- earthquake and tectonic studies
- Electromagnetic Launch and Propulsion Technology
- Gyrotron and Vacuum Electronics Research
- Superconducting Materials and Applications
- Ocean Waves and Remote Sensing
- Advanced Optical Sensing Technologies
Imperial College London
2018-2024
Heinz Maier-Leibnitz Zentrum
2024
Technical University of Munich
2024
First Light Fusion
2021
Brookdale University Hospital and Medical Center
2020
SUNY Downstate Health Sciences University
2020
State University of New York
2020
Weston Solutions (United States)
2013
Patrick Air Force Base
2006
University of Colorado Boulder
1985
Decreases in immune responsiveness with age contribute to the increased incidence and severity of infectious disease among elderly adults. The response immunization also decreases advancing age. Lifestyle factors (exercise, diet) have been established play an important role immunosenescence, practice "healthy" behavior may minimize age-associated decline function. objective this study was determine whether exercise, diet, psychosocial were associated altered influenza vaccine.Adults aged 62...
We present results from pulsed-power driven differentially rotating plasma experiments designed to simulate physics relevant astrophysical disks and jets. In these experiments, angular momentum is injected by the ram pressure of ablation flows a wire array Z pinch. contrast previous liquid metal rotation not boundary forces. Axial gradients launch jet upward, which confined combination ram, thermal, magnetic surrounding halo. The has subsonic rotation, with maximum velocity 23±3 km/s....
A major problem with time-domain measurements of seismic surface waves is the significant effect nondispersed Rayleigh and Airy phases, which can occur at both regional teleseismic distances. This article derives a method for measuring minimum digital processing by using zero-phase Butterworth filters. The effectively measure surface- wave magnitudes distances, variable periods between 8 25 sec, while ensuring that are corrected to accepted formulae 20-sec reference periods, thus providing...
Optical collective Thomson scattering (TS) is used to diagnose magnetized high energy density physics experiments at the Magpie pulsed-power generator Imperial College London. The system uses an amplified pulse from second harmonic of a Nd:YAG laser (3 J, 8 ns, 532 nm) probe wide diversity high-temperature plasma objects, with densities in range 1017–1019 cm−3 and temperatures between 10 eV few keV. scattered light collected 100 μm-scale volumes within plasmas, which are imaged onto optical...
Abstract A supersonic flow of magnetized plasma is produced by the application a 1 MA-peak, 500 ns current pulse to cylindrical arrangement parallel wires, known as an inverse wire array. The J × B acceleration ablated material, and magnetic field several Tesla embedded at source driving current. This setup has been used for variety experiments investigating interactions flows. In designed investigate reconnection, collision counter-streaming flows, carrying oppositely directed fields, leads...
Abstract We present a monoenergetic positron beam specifically tailored to the needs of (near-) surface annihilation spectroscopy. The Setup for LOw-energy Positron Experiments (SLOPE) comprises high-activity 22 Na source, tungsten moderator, electrostatic extraction and acceleration, magnetic guidance, as well an analysis chamber with movable sample holder γ -ray detection system. moderator foil, biased between 0 30 V, in combination HV-biasable holder, enables implantation energies 3 eV 40...
We present a study of perpendicular subcritical shocks in collisional laboratory plasma. Shocks are produced by placing obstacles into the supermagnetosonic outflow from an inverse wire array z pinch. demonstrate existence this regime and find that secondary form downstream. Detailed measurements shock structure confirm absence hydrodynamic jump. calculate classical (Spitzer) resistive diffusion length show it is approximately equal to width. measure little heating across (<10% ion kinetic...
We present a technique to measure the time-resolved velocity and ion sound speed in magnetized, supersonic high-energy-density plasmas. place an inductive (“b-dot”) probe pulsed-power-driven plasma flow magnetic field advected by plasma. As Reynolds number is large (RM &gt; 10), advects proportional current at load. This enables us estimate as function of time from delay between load signal probe. The also generates hydrodynamic bow shock around probe, structure which depends on upstream...
We investigate three-dimensional (3-D) bow shocks in a highly collisional magnetized aluminium plasma, generated during the ablation phase of an exploding wire array on MAGPIE facility (1.4 MA, 240 ns). Ablation plasma from generates radially diverging, supersonic ( $M_S \sim 7$ ), super-Alfvénic $M_A > 1$ ) flows with frozen-in magnetic flux $R_M \gg ). These collide inductive probe placed flow, which serves both as obstacle that shock, and diagnostic advected field. Laser interferometry...
This work presents a magnetic reconnection experiment in which the kinetic, magnetic, and thermal properties of plasma each play an important role overall energy balance structure generated layer. Magnetic occurs during interaction continuous steady flows super-Alfvénic, magnetized, aluminum plasma, collide geometry with two-dimensional symmetry, producing stable long-lasting Optical Thomson scattering measurements show that when layer forms, ions inside are more strongly heated than...
Recent pulsed-power experiments have demonstrated the formation of astrophysically relevant, differentially rotating plasmas. Key features plasma flows are discovery a quasi-Keplerian rotation curve, launching highly collimated angular-momentum-transporting axial jets, and hollow density structure sustained by centrifugal barrier effect. In this communication, we discuss several in these through order-of-magnitude models. First, show that observed velocity would produce force strong enough...
Yield estimation of small explosions at local distances represents a challenge for the nuclear explosion monitoring community. We have examined feasibility using short‐period surface‐wave magnitudes, called ![Graphic][1] , to estimate yields ( . also incorporated multiple excitation corrections ![Graphic][3] based on near‐source seismic velocities, which greatly affect source‐region amplitudes ![Graphic][4] It is important note that in formula estimated from measured ![Graphic][5] group...
We report on a recently developed laser-probing diagnostic, which allows direct measurements of ray-deflection angles in one axis while retaining imaging capabilities the other axis. This us to measure spectrum angular deflections from laser beam, passes through turbulent high-energy-density plasma. contains information about density fluctuations within plasma, deflect probing over range angles. create synthetic diagnostics using ray-tracing compare this new diagnostic with standard...
We present first results from a novel experimental platform that is able to access physics relevant topics including indirect-drive magnetized inertial confinement fusion, laser energy deposition, various in atomic physics, and laboratory astrophysics (for example, the penetration of B-fields into high density plasmas). This uses x rays wire array Z-pinch irradiate silicon target, producing an outflow ablated plasma. The plasma expands ambient, dynamically significant (∼5 T), which are...
The equilibrium states described by a damped and driven kinetic equation governing the evolution of spectrum radiation in stationary Langmuir-turbulent plasma are studied. Both Langmuir transverse spectra assumed to be one-dimensional wavenumber space. A source at frequency uniform rate dissipation higher harmonics assumed. is characterized an effective temperature z, proportional energy density inversely waves. If z&lt;1 photon decreases with increasing as power law z. z&gt;1,...
ABSTRACT We report on the results of a simulation-based study colliding magnetized plasma flows. Our set-up mimics pulsed power laboratory astrophysical experiments but, with an appropriate frame change, is relevant to jets internal velocity variations. track evolution interaction region where two flows collide. Cooling via radiative losses included in calculation. systematically vary beta (βm) flows, strength cooling (Λ0), and exponent (α) temperature dependence function. find that for...
We present a detailed characterization of the structure and evolution differentially rotating plasmas driven on MAGPIE pulsed-power generator (1.4 MA peak current, 240 ns rise-time). The experiments were designed to simulate physics relevant accretion discs jets laboratory scales. A cylindrical aluminium wire array Z pinch enclosed by return posts with an overall azimuthal off-set angle was produce ablation plasma flows that propagate inwards in slightly off-radial trajectory, injecting...
We present a detailed characterization of the structure and evolution differentially rotating plasmas driven on MAGPIE pulsed-power generator (1.4 MA peak current, 240 ns rise time). The experiments were designed to simulate physics relevant accretion discs jets laboratory scales. A cylindrical aluminium wire array Z pinch enclosed by return posts with an overall azimuthal off-set angle was produce ablation plasma flows that propagate inwards in slightly off-radial trajectory, injecting...
We present a monoenergetic positron beam specifically tailored to the needs of (near-) surface annihilation spectroscopy. The Setup for LOw-energy Positron Experiments (SLOPE) comprises high-activity 22Na source, tungsten moderator, electrostatic extraction and acceleration, magnetic guidance, as well an analysis chamber with movable sample holder {\gamma}-ray detection system. moderator foil, biased between 0 30 V, in combination HV-biasable holder, enables implantation energies 3 eV 40...
We present a study of subcritical shocks in highly collisional laboratory plasma with dynamically significant magnetic field. Shocks were produced by placing cylindrical obstacles into the supermagnetosonic ( $M_{{\rm MS}} \sim 1.9$ ) outflow from an inverse wire array z-pinch at MAGPIE pulsed power facility $n_{e} 8.5 \times 10^{17}\,{\rm cm}^{-3}$ , $v 45\,{\rm km}\,{\rm s}^{-1}$ ). demonstrate existence this regime and find that secondary stagnation form downstream which we infer...
We study the structure of reverse shocks formed by collision supersonic, magnetized plasma flows driven an inverse (or exploding) wire array with a planar conducting obstacle. observe that these varies dramatically material, despite similar upstream flow velocities and mass densities. For aluminum arrays, shock is sharp well-defined, consistent magneto-hydrodynamic theory. In contrast, we do not well-defined using tungsten wires, instead see broad region dominated density fluctuations on...
Three‐dimensional (3-D) seismic reflection surveys have been the subject of much recent interest. However, use refraction technique (Musgrave, 1967) in 3-D analyses should also be considerable utility even though homogeneous layers separated by planar interfaces (not necessarily parallel or horizontal) must assumed most applications. A particular advantage method is straightforward determination velocities.