A5038998753- Laser-Plasma Interactions and Diagnostics
- Nuclear Physics and Applications
- Magnetic confinement fusion research
- Laser-induced spectroscopy and plasma
- Plasma Diagnostics and Applications
- Radiation Detection and Scintillator Technologies
- Pulsed Power Technology Applications
- Electrostatic Discharge in Electronics
- Ion-surface interactions and analysis
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Laser Design and Applications
- Gyrotron and Vacuum Electronics Research
- Ionosphere and magnetosphere dynamics
- Atomic and Molecular Physics
- Mass Spectrometry Techniques and Applications
- Astro and Planetary Science
- Advanced Data Storage Technologies
- Radiation Therapy and Dosimetry
- Lattice Boltzmann Simulation Studies
- Plasma and Flow Control in Aerodynamics
- Vacuum and Plasma Arcs
- Integrated Circuits and Semiconductor Failure Analysis
- Advanced Sensor Technologies Research
- Atomic and Subatomic Physics Research
United States Naval Research Laboratory
2014-2025
Naval Research Laboratory Plasma Physics Division
2014-2022
National Academies of Sciences, Engineering, and Medicine
2007-2009
L-3 Communications (United States)
2009
Alameda Applied Sciences Corporation (United States)
2009
Pulse Biosciences (United States)
2009
Sandia National Laboratories
2009
National Postdoctoral Association
2008
National Research Council Canada
2008
National Health Council
2007
An optical emission spectroscopic (OES) and imaging characterization is conducted on N2 plasmas generated by a 100 keV fast-pulsed electron beam. The beams are injected into an gas filled volume with current of 4.5 kA (300 A/cm2) ns pulse width. at the pressures, 1 Torr 0.1 Torr, corresponding to two distinct regimes that exhibit significantly different plasma dynamics. Beam impact ionization shown be primary mechanism for producing low temperature during beam output. After termination,...
The stabilizing effect of a sheared axial flow on the m=1 kink instability in Z pinches has been studied numerically with linearized ideal magnetohydrodynamic model to reveal that stabilizes mode when shear exceeds threshold. is investigated ZaP (Z-Pinch) Flow Z-pinch experiment at University Washington. An axially flowing pinch generated 1 m coaxial accelerator coupled assembly chamber. plasma assembles into 50 cm long radius approximately cm. azimuthal array surface mounted magnetic probes...
Z-pinch experiments with a hybrid configuration of deuterium gas puff have been carried out on the HAWK (NRL, Washington, DC) and GIT-12 (IHCE, Tomsk) pulsed power generators at 0.7 MA 3 currents, respectively. On GIT-12, neutron yields reached an average value 2 × 1012 neutrons, deuterons were accelerated up to energy 30 MeV. This was 50 times ion provided by generator driving voltage 0.6 MV highest observed in z-pinches dense plasma foci. To confirm these unique results independently...
We report ultrashort pulse, 1 kHz repetition rate x-ray generation in the 5–20 keV spectral region, induced by interaction of laser radiation with copper nitrate solution and ethylene glycol liquid-jet targets. The characteristics source are relevant for application to time-resolved diffraction studies as well spectroscopic absorption studies. sources were operated uninterrupted excess 5 h no detectable buildup debris on associated optics. flux generated both is estimated be order 106...
A pinch-reflex ion diode is fielded on the pulsed-power machine Mercury (R. J. Allen, et al., 15th IEEE Intl. Pulsed Power Conf., Monterey, CA, 2005, p. 339), which has an inductive voltage adder (IVA) architecture and a magnetically insulated transmission line (MITL). operated in positive polarity resulting layered MITL flow as emitted electrons are born at different potential each of cavities. The usual method for estimating by measuring bound current cathode anode not accurate with flow,...
Intense pulsed active detection (IPAD) is a promising technique for detecting fissile material to prevent the proliferation of special nuclear materials. With IPAD, fissions are induced in brief, intense radiation burst and resulting gamma ray or neutron signals acquired during short period elevated signal-to-noise ratio. The 8 MV, 200 kA Mercury pulsed-power generator at Naval Research Laboratory coupled high-power vacuum diode produces an 30 ns bremsstrahlung beam study this approach. work...
A holographic interferometer is used to determine the radial electron number density profile of a sheared-flow Z pinch. Chord-integrated information recorded during plasma pulse using expanded beam pulsed ruby laser and techniques. An Interactive Data Language (IDL) computer routine that requires only minimal user interaction measure resulting fringe shift in reconstructed interferogram. This chord-integrated inverted an Abel inversion profile. The profiles obtained show radially symmetric...
In intense, pulsed active detection, a single, intense pulse of radiation is used to induce photofission in fissionable material, increasing its detectability. The Mercury pulsed-power generator was converted positive polarity (+3.7 MV, 325 kA, 50-ns FWHM) drive an source based on the FIGARO detection concept. probing consisted ion-beam diode and thick PTFE (Teflon) converter where 6-7 MeV γ-rays were produced via <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
The distribution of argon gas injected by a 12-cm-diameter triple-shell nozzle was characterized using both planar, laser-induced fluorescence (PLIF) and high-sensitivity interferometry. PLIF is used to measure the density at given time detecting from an acetone tracer added gas. Interferometry involves making time-dependent, line-integrated measurements series chordal locations that are then Abel inverted obtain distribution. Measurements were made on nominally identical nozzles later for...
Active interrogation is a method used to enhance the likelihood of detection shielded special nuclear material (SNM); an external source radiation interrogate target and stimulate fission within any SNM present. Radiation produced by process can be detected infer presence SNM. The Atomic Weapons Establishment (AWE) Naval Research Laboratory (NRL) have carried out joint experimental study into use single pulse, high-intensity sources bremsstrahlung x-rays D(\gammab, n)H photoneutrons in...
After 616 shots in a negative polarity configuration, Mercury, 6-MV and 300-kA inductive voltage adder (IVA), has been converted to positive order extract ion beams. Conversion was achieved by rotating all six of the cells 180°. In principle, we could have chosen instead insert center conductor from other end change polarity, but minimized time required make transition. Although most same pieces were used, had be reconfigured align transition with cell feed gaps. Because electron flow...
An ongoing programme investigating the active detection of special nuclear material (SNM) is being undertaken by Atomic Weapons Establishment (A WE) in collaboration with Naval Research Laboratory (NRL). As part this programme, NRL Mercury IVA was operated negative polarity mode to produce an 8MeV endpoint bremsstrahlung spectrum, which turn used induce photofission a depleted uranium (DU) sample. Twenty-six experiments were fielded March 2011 twenty-seven detectors fielded, including <sup...
A WE is developing a prototype active interrogation system to enable robust detection of shielded nuclear material within the context border choke point detection. This paper describes study which took place in order determine optimum type radiation and pulse structure be used with system. wide variety neutron gamma sources were considered including use sub 10 MeV end-point energy bremsstrahlung or <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Naval Research Laboratory is starting to study the connection between plasma instabilities and fast ion acceleration for neutron production on a dense focus (DPF). The experiments will be performed HAWK generator (665 kA) that has rise time, 1.2 μs, high inductance, 720 nH. There conjecture yield DPF may enhanced high-impedance generator, since assembly axis not significantly reduce current drive. Furthermore, prevent upstream breakdown during implosion, there are plans inject gas load as...
A high-power, high-impedance ion beam diode has been fielded on the Mercury inductive voltage adder at typical parameters of 4 MV, 360 kA, and 70-90-kA current. These results are consistent with theory LSP calculations. This is focused onto a CF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> target to produce characteristic gammas via <sup xmlns:xlink="http://www.w3.org/1999/xlink">19</sup> F(p,¿¿)...
Summary form only given. A series of experiments has been performed on the Mercury generator (8 MV, 200 kA, 50 ns) to investigate use a single, intense radiation pulse induce photo fission. In these studies, plate depleted uranium (DU) is irradiated by 8 MV-endpoint bremsstrahlung produced Mercury. Within this x-ray pulse, photons whose energies lie above threshold 5.26 MeV fission in DU, producing about 2.7 neutrons per The consist two populations: prompt neutrons, which escape DU within...
A fusion space thruster based on the flow-stabilized Z-pinch may be possible in near-term and provide many advantages over other fusion-based concepts. The Zpinch equilibrium is classically unstable to gross disruption modes according theoretical, numerical, experimental evidence. However, a new stabilization mechanism has been discovered that can stabilize these with plasma flow. stabilizing was developed for which an axial velocity profile linear radius. When shear exceeds threshold, are...
The 670 kA Hawk pulsed power generator at NRL has been configured as a fast (1.2 μs rise time), high inductance (607 nH) driver for dynamic dense plasma focus (DPF) load in order to create testbed the study of charged particle acceleration mechanisms imploding plasmas. current pulse is initiated deuterium injected radially by three Marshall guns. This accelerated through coaxial region, and pinches onto neutral axially gas-puff valve. Promising experimental results along with recent...
We irradiated a depleted uranium ( <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">238</sup> U) target with intense, single 50 ns pulses of bremsstrahlung to study the behavior xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> He, BF3, NaI(Tl), and liquid scintillation detectors in harsh radiological environment. The was exposed unshielded, shielded borated high-density polyethylene, or steel, delayed γ-ray neutron signatures were measured....
In this paper, the MCNPX code is used to optimize moderator materials and thicknesses for a neutron detector based on <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> Li-loaded glass scintillator. It shown that response of Li delayed-neutron-fission spectrum comparable xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> He-based gas proportional counter configured with similar active area materials. For delayed-neutron spectrum,...
An ongoing program me looking at the active detection of special nuclear material (SNM) is being undertaken by Atomic Weapons Establishment (A WE) in collaboration with Naval Research Laboratory (NRL). As part this programme, pulsed-power driven neutron experiments were conducted NRL Mercury accelerator. was used a positive polarity mode to produce and accelerate protons into lithium metal foils, generating neutrons via <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Abstract Acceleration of ions to multi-MeV energies is investigated in various plasma devices better understand processes astrophysical plasmas and develop efficient accelerators for a variety applications. This paper reports the production proton, deuteron, electron beams z-pinch—a cylindrically symmetric column that compressed by its own magnetic field. For this work, GIT-12 pulsed-power generator was used drive novel configuration z-pinch dramatically enhanced ion acceleration associated...
Aims: The dosages and efficacy of 14 ultraviolet (UV) decontamination technologies were measured against a SARS-CoV-2 surrogate virus that was dried onto different materials for laboratory field testing. Methods results: A live enveloped, ribonucleic acid (RNA) on stainless steel 304 (SS304), Navy Top Coat-painted SS304 (NTC), cardboard, polyurethane, polymethyl methacrylate (PMMA), acrylonitrile butadiene styrene (ABS) at > 8.0 log10 plaque-forming units (PFU) per test coupon. coupons then...