A5008558963- Plasma Diagnostics and Applications
- Fusion and Plasma Physics Studies
- Carbon Nanotubes in Composites
- Graphene research and applications
- Astro and Planetary Science
- Planetary Science and Exploration
- Laser-Plasma Interactions and Diagnostics
- Nuclear Physics and Applications
- Magneto-Optical Properties and Applications
- Pulsed Power Technology Applications
- Particle Detector Development and Performance
- Spacecraft and Cryogenic Technologies
- Boron and Carbon Nanomaterials Research
- Particle accelerators and beam dynamics
- Cold Fusion and Nuclear Reactions
- Radiation Effects in Electronics
- Gyrotron and Vacuum Electronics Research
- Magnetic confinement fusion research
- Semiconductor materials and devices
- Radiation Detection and Scintillator Technologies
- Pulsars and Gravitational Waves Research
- Laser Design and Applications
- Space Science and Extraterrestrial Life
- Fullerene Chemistry and Applications
- Dark Matter and Cosmic Phenomena
Sandia National Laboratories
2017-2024
Sandia National Laboratories California
2021-2022
Honeywell (United States)
2019
Proton (United Kingdom)
2014
University of Illinois Urbana-Champaign
2008-2013
Michigan Technological University
2004-2010
We observed current density (J) dependent degradation in field emission from multiwalled carbon nanotubes (MWCNTs). These degradations are recoverable and can be explained by current-induced dislocations along the MWCNTs. MWCNTs grown thermal chemical vapour deposition (CVD) emit stable continuously for at least 1200 min with upper limits of approximately 0.5 mA cm(-2). In contrast, this limit is<40 microA cm(-2) plasma-enhanced CVD (PECVD), although higher J is possible relatively shorter...
Plasma-enhanced chemical vapor deposition is the only technique for growing individual vertically aligned multiwalled carbon nanotubes (VA-MWCNTs) at desired locations. Inferior graphitic order has been a long-standing issue that prevented realistic applications of these VA-MWCNTs. Previously, VA-MWCNTs were grown by one-plasma approach. Here, we demonstrate capability controlling and diameters decoupling functions conventional single plasma into dual-plasma configuration. Our results...
Quark nuggets are a candidate for dark matter consistent with the Standard Model. Previous models of quark have investigated properties arising from their being composed strange, up, and down quarks not included any effects caused by self-magnetic field. However, Tatsumi found that core magnetar star may be nugget in ferromagnetic state magnetic field B between $10^{ 11}$ T 13}$ T. We apply Tatsumi$'$s result to quark-nugget dark-matter report results on aggregation magnetized (MQNs) after...
Nanotubes have significant portions of their atoms located at the surfaces and represent future biological devices. With such small dimensions, sensitivities applications previously impossible are being made real. Not all nanomaterials currently same level proficiency, however. Carbon nanotubes a mature, easily grown controlled nanostructure, but boron nitride zinc oxide still coming into own. Yet progress in three species is making easier than before.
Graduate Research Assistant, Aerospace Engineering, 306 Talbot Laboratory, MC-236, 104 South Wright Street, Urbana, IL 61801. Member, AIAA. 2,3,4 Nuclear, Plasma and Radiological 216 MC-234, 61801 5 Professor Emeritus, Associate Fellow, Helicon Injected Inertial Electrostatic Rocket (HIIPER): Experimental Proof of Principle
A new collimated filtered thermoluminescent dosimeter (TLD) array has been developed at the Z facility to characterize warm x-rays (hν > 10 keV) produced by pinch radiation sources. This includes a Kapton debris shield assembly protect TLDs from source debris, collimator limit field of view region, filter wheel containing filters aluminum, copper and tungsten up 3 mm thick independently each TLD, hermetically sealed cassette as well shielding on sides back minimize scattered reaching TLDs....
Nanotubes represent a unique class of materials in which all atoms are located near the surface. Since electrons flowing through nanotubes confined surface, attractive for sensing biological and chemical molecules. In addition, their tubular structures enable nanofluidic devices that useful novel applications. this paper, we will discuss current applications latest advancements on growth carbon (CNTs), boron nitride (BNNTs), ZnO (ZnONTs). First, CNT is highly controlled by regulating...
Abstract Quark nuggets are theoretical objects composed of approximately equal numbers up, down, and strange quarks. They also called strangelets, nuclearites, AQNs, slets, Macros, MQNs. a candidate for dark matter, which has been mystery decades despite constituting ~ 85% the universe’s mass. Most previous models quark have assumed no intrinsic magnetic field; however, Tatsumi found that may exist in magnetars as ferromagnetic liquid with field B S = 10 12±1 T. We apply result to nuggets,...
One of the most fundamental processes in Universe, nucleosynthesis elements drives energy production stars as well creation all atoms heavier than hydrogen. To harness this process and open new ways for production, we must recreate some extreme conditions which it occurs. We present results experiments using a pulsed power facility to induce collective nuclear interactions producing stable nuclei virtually every element periodic table. A high-power electron beam pulse striking small metallic...
The Helicon Injected Inertial Plasma Electrostatic Rocket (HIIPER) is an electric propulsion method being studied for potential use on deep space probes. Recent work done HIIPER has resulted in increased understanding of the physics involved: Experimental studies have shown that with present experiment, plasma beam composed primarily electrons. However, as a device, would need to expel energetic ions produce high thrust. computational been performed indicate extraction may be possible using...
We describe a direct absolute magneto-optical approach to measuring the magnetic field driven by long pulse width (&gt;5 ms) and high electrical current (∼kA) in solenoidal coil. The are among most important operating parameters lightning research power distribution essential understanding properties of radiation output pulsed energy accelerators as well other platforms. However, accurately these fields currents using conventional diagnostics is difficult due strength ionizing...
Graduate Research Assistant, Aerospace Engineering, 306 Talbot Laboratory, MC-236, 104 South Wright Street, Urbana, IL 61801. Member, AIAA. 2,3,4 Nuclear, Plasma and Radiological 216 MC-234, 61801 5 Professor Emeritus, Associate Fellow, Numerical Experimental Measurements in a HeliconIEC Thruster
We describe a direct magneto-optical approach to measuring the magnetic field driven by narrow pulse width (&lt;10 ns), 20 kA electrical current flow in transmission line of high energy pulsed power accelerator. The and are among most important operating parameters accelerator critical understanding properties radiation output. However, accurately these fields currents using conventional diagnostics is difficult due strength ionizing electromagnetic interference. Our uses fiber coupled...
Saturn is a short-pulse ( <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">~</sub> 40 ns FWHM) x-ray generator capable of delivering up 10 MA into bremsstrahlung diode to yield 5 × 10^12 rad/s (Si) per shot at an energy 1 2 MeV. With the machine now over 30 years old it necessary rebuild and replace many components, upgrade controls diagnostics, design for more reliability reproducibility, and, as possible accelerator produce current low voltage...
The electric field strength between the cathode and anode (i.e., voltage) of a pulsed power machine is one most important operating parameters device. However, to date, accurate precise voltage measurements on these high energy systems have proved difficult if not virtually impossible perform. In many cases, be performed take place in an environment cluttered with electromagnetic interference (EMI), radio frequency (RFI), electron pollution, there potential for electrical discharge (or...
The design basis for a possible near-term driven subcritical assembly student labs using cylindrical Inertial Electrostatic Confinement (IEC) fusion neutron source is described. rebirth of nuclear fission power going to require new generation training facilities students. IEC provides very versatile facility such training. can provide various wave forms (pulses, sinusoidal ramp, etc.) by varying the applied voltage. This opens up an important class dynamic experiments lab study. Driven...