A5046527353- Plasma Diagnostics and Applications
- Magnetic confinement fusion research
- Fusion materials and technologies
- Laser-induced spectroscopy and plasma
- Particle accelerators and beam dynamics
- Nuclear Materials and Properties
- Ionosphere and magnetosphere dynamics
- Electrohydrodynamics and Fluid Dynamics
- Astro and Planetary Science
- Ion-surface interactions and analysis
- Nuclear reactor physics and engineering
- Plasma Applications and Diagnostics
- Metal and Thin Film Mechanics
- Analytical chemistry methods development
- Laser-Plasma Interactions and Diagnostics
- Catalytic Processes in Materials Science
- Advanced Surface Polishing Techniques
- Advanced Machining and Optimization Techniques
- Superconducting Materials and Applications
- Space Satellite Systems and Control
- Dust and Plasma Wave Phenomena
- Advanced Data Storage Technologies
- Electrostatic Discharge in Electronics
- Geomagnetism and Paleomagnetism Studies
- Electron and X-Ray Spectroscopy Techniques
University of Illinois Urbana-Champaign
2015-2024
West Virginia University
2020
National Center for Supercomputing Applications
2012-2019
Max Planck Society
2019
Max Planck Institute for Plasma Physics
2019
University of Illinois System
2017
Lawrence Livermore National Laboratory
2017
Urbana University
2014
University of Padua
2008-2012
University of California, Los Angeles
2011
Determination of the mechanisms underlying growth tungsten fuzz is an important step towards mitigation formation. Nanostructured was produced on resistively heated wires in a helicon plasma source (maximum flux 2.5 × 1021 m−2 s−1). Asymmetry setup allows for investigation temperature and effects single sample. An effort at elucidating mechanism formation made by inspecting SEM micrographs nanostructured successive fluence steps helium ions up to 1 1027 m−2. To create these sample exposed...
The ion energy-angle distribution (IEAD) at the wall of a magnetized plasma is fundamental importance for determination material processes occurring plasma-material interface, comprising secondary emissions and sputtering. Here, we present numerical characterization IEAD weakly collisional with magnetic field inclined an arbitrary angle respect to wall. analysis has been done using two different techniques: (1) fluid-Monte Carlo method, (2) particle-in-cell simulations, former offering fast...
Radiofrequency discharges used in industry often have centrally peaked plasma density profiles n(r) although ionization is localized at the edge, even presence of a dc magnetic field. This can be explained with simple cylindrical model one dimension as long short-circuit effect endplates causes Maxwellian electron distribution. Surprisingly, universal profile obtained, which self-similar for all uniform temperature Te and neutral nn. When collisions ionizations are radially accounted for,...
For successful commercial adaptation of the μ-EDM (micro electro-discharge machining) process, there is a need to increase process efficiency by understanding mechanism. This paper presents model plasma discharge phase single event in deionized water. The modeled using global approach which assumed be spatially uniform, and equations mass energy conservation are solved simultaneously along with dynamics bubble growth. Given input voltage, current gap, complete temporal description during...
Recent advances in vacuum sciences and applications are reviewed. Novel optical interferometer cavity devices enable pressure measurements with ppm accuracy. The innovative dynamic standard allows for temporal resolution of 2 ms. Vacuum issues the construction huge ultra-high worldwide surface science thin films include new phenomena observed electron transport near solid surfaces as well novel results on properties carbon nanomaterials. Precise techniques thin-film characterization have...
Plasma-facing component (PFC) geometries are evaluated for a Fusion Nuclear Science Facility (FNSF) design to find solutions that compatible with flowing liquid lithium components while satisfying requirements from the perspective of plasma and neutral particle transport. Flowing metal (LM) divertor systems offer important advantages due continual regeneration surface material, but may require modifications standard optimized tokamak designs. Scrape Off Layer Plasma Simulator International...
Abstract Here, we present a one-dimensional, time-dependent multi-physics model of plasma–liquid interface that encompasses both the plasma and liquid phases using MOOSE-based drift–diffusion–reaction software, Zapdos-Crane. The was applied to an experimental configuration comprised direct-current powered argon formed at surface aqueous, ionically conductive solution. In this system, one reactions occurs is formation hydroxyl radicals, which subsequently produce hydrogen peroxide. We studied...
This paper presents a micro-electrodischarge machining (EDM) melt-pool model to predict workpiece (anode) material removal from single discharge micro-EDM process. To the melt-pool, heat transfer and fluid flow equations are solved in domain containing dielectric material. A level set method is used identify solid liquid fractions of when molten by plasma flux. The flux, pressure radius bubble have been estimated serve as inputs volume removed surface workpiece. Experiments carried out study...
Computational optimization has revolutionized the field of stellarator design. To date, optimizations have focused primarily on neoclassical confinement and ideal MHD stability, although limited other parameters also been performed. The purpose this paper is to outline a select set new concepts for that, when taken as group, present significant step forward in concept. One criticisms that leveled at existing methods design complexity resultant coils. Recently, coil code—COILOPT++, which uses...
The long-standing problem of plasma diffusion across a magnetic field (B-field) is reviewed, with emphasis on low-temperature linear devices finite length the aligned along an axis symmetry. In these partially ionized plasmas, cross-field transport dominated by ion?neutral collisions and can be treated simply fluid equations. Nonetheless, electron confinement complicated sheath effects at endplates, must accounted for to get agreement experiment.
Partially ionized gas discharges used in industry are often driven by radiofrequency (rf) power applied at the periphery of a cylinder. It is found that plasma density n usually flat or peaked on axis even if skin depth rf field thin compared with chamber radius a. Previous attempts explaining this did not account for finite length discharge and boundary conditions endplates. A simple 1D model to focus basic mechanism: short-circuit effect. strong electric (E-field) scaled electron...
We have measured vibronic emission spectra of an oxide uranium formed after laser ablation the metal in gaseous oxygen. Specifically, we time-dependent relative intensity a band located at approximately 593.6 nm 16O2. This grew to neighboring atomic features as function time oxygen environment but was relatively invariant with argon. In addition, spectral shift this 18O2 atmosphere. Based on shift, and by comparison earlier results obtained from free-jet expansion excitation, can confirm...
The application of liquid metal, especially lithium, as a plasma facing component (PFC) has the capacity to offer strong alternative solid PFCs by reducing damage concerns and enhancing performance. liquid-metal infused trenches (LiMIT) concept is metal divertor which employs thermoelectric current from either or external heating in tandem with toroidal field self-propel lithium through series trenches. LiMIT was tested linear simulator, Magnum PSI, at heat fluxes up 3 MW m−2. Results these...
High-temperature chemistry in laser ablation plumes leads to vapor-phase speciation, which can induce chemical fractionation during condensation. Using emission spectroscopy acquired after of a SrZrO3 target, we have experimentally observed the formation multiple molecular species (ZrO and SrO) as function time plume evolves. Although stable oxides SrO ZrO2 are both refractory, from ZrO intermediate at earlier times than SrO. We deduced time-scale oxygen entrainment into using an 18O2...
Laser ablation is an easily accessible method of producing metallic plasmas in reactive, atmospheric environments. The use laser for the study uranium plasma chemistry plumes highly relevant nuclear forensics and standoff detection, but behavior such systems currently not well understood. One main difficulties studying these that already considerable complexity plume dynamics vacuum conditions further enhanced by shockwave formation plasma-chemical Therefore, order to understand system, both...
Ion-material interactions are of vital importance in industrial applications, the study and design nuclear fusion devices, engineering survivable spacecraft components, more.In particular, plasma-material typically dominated by ion-material interactions, including phenomena sputtering, reflection, implantation.These difficult to model analytically, many such models rely on empirical or semi-empirical formulas, as Yamamura sputtering yield formula (Y.Yamamura, 1982), Thomas reflection...
Abstract Integrated modeling of plasma-surface interactions provides a comprehensive and self-consistent description the system, moving field closer to developing predictive design capabilities for plasma facing components. One such workflow, including descriptions scrape-off-layer plasma, ion-surface sub-surface evolution, was previously used address steady-state scenarios has recently been extended incorporate time-dependence two-way information flow. The new model can dynamic recycling in...