A5033788385- Fusion materials and technologies
- Magnetic confinement fusion research
- Superconducting Materials and Applications
- Nuclear Materials and Properties
- Nuclear Physics and Applications
- Laser-Plasma Interactions and Diagnostics
- Semiconductor materials and devices
- Laser-induced spectroscopy and plasma
- Silicon and Solar Cell Technologies
- Plasma Diagnostics and Applications
- Cold Fusion and Nuclear Reactions
- Advancements in Semiconductor Devices and Circuit Design
- Integrated Circuits and Semiconductor Failure Analysis
- Additive Manufacturing and 3D Printing Technologies
- Additive Manufacturing Materials and Processes
- Transition Metal Oxide Nanomaterials
- Ga2O3 and related materials
- Advanced Manufacturing and Logistics Optimization
- Planetary Science and Exploration
- Electron and X-Ray Spectroscopy Techniques
- Advanced Materials Characterization Techniques
- Radioactive contamination and transfer
- Electronic and Structural Properties of Oxides
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
Oak Ridge National Laboratory
2021-2024
University of Tennessee at Knoxville
2016-2024
Technological University of the Philippines
2024
University of the Philippines Visayas
2024
Knoxville College
2018-2022
Max Planck Society
2019
Max Planck Institute for Plasma Physics
2019
Abstract A set of experiments are planned to exploit the high SOL collisionality enabled by a tightly baffled slot divertor geometry suppress tungsten leakage in DIII-D. toroidal row graphite tiles from Small Angle Slot (SAS) is being coated with 10–15 μ m tungsten. New spectroscopic viewing chords in-vacuo optics will measure W gross erosion source surface spatial and temporal resolution. In parallel, bottom SAS changed flat ‘V’ shape. SOLPS-ITER/DIVIMP simulations conducted drifts using...
Mixed-material DIVIMP–WallDYN modeling, now incorporating ExB drifts, is presented that simultaneously reproduces tungsten (W) erosion and deposition patterns observed during the DIII-D metal rings campaign, in which a toroidally symmetric set of W-coated tiles were installed carbon (C) divertor. Since most reactor plasma facing component (PFC) designs call for mixed-material environments, including ITER's W/Be environment, divertor targets will quickly evolve into reconstituted surfaces...
Abstract A novel impurity transport model that approximates SOL turbulence as a fluctuating poloidal electric field is shown to be an acceptable replacement for the traditional approach of assigning arbitrary radial diffusion coefficient ions. The implemented in DIVIMP code and applied L-Mode tungsten divertor experiment on DIII-D. represented between ±1000 V m −1 based previous measurements. resulting intermittent v r = E θ × B T causes ions both into core well far-SOL. Simultaneous...
Triplet sets of replaceable graphite rod collector probes (CPs), each with collection surfaces on opposing faces and oriented normal to the magnetic field, were inserted at outboard mid-plane DIII-D study divertor tungsten (W) transport in Scrape-Off Layer (SOL). Each CP collects particles along field lines different parallel sampling lengths (determined by diameters SOL transport) giving radial profiles from main wall inward R-Rsep ∼ 6 cm. The CPs deployed a first-of-a-kind experiment using...
Abstract Near-separatrix impurity accumulation between the crown and outer midplane of tokamaks is a common feature in results from codes such as SOLPS-ITER DIVIMP; however, experimental evidence has only recently been obtained reported here. The find that poloidal distribution ions scrape-off layer (SOL) depends primarily on toroidal field ( B T )-dependent parallel flow patterns background plasma ion temperature gradient (∇ ‖ ) force. Experimentally, Mach probes used L-mode plasmas with...
A basic stable isotope mixing model (bSIMM) is presented that enables the first-time use of multiple isotopic tungsten (W) tracers in a fusion device. DIII-D installed two toroidally symmetric, but poloidally distinct, arrays tiles outer region lower divertor are each distinguishable by different stable-isotope signatures W. This installation was called metal rings campaign. Experiments were then carried out with this setup to assess W source from location and how sourced led contamination...
Collector probes have long been used to measure impurity fluxes in the scrape off layer (SOL) of tokamaks. In this study, collector were inserted main SOL DIII-D during tungsten Metal Rings Campaign, and W deposits on analyzed ex situ using Rutherford backscattering spectrometry analysis obtain radial profiles deposition. A simple picture is hypothesized for how transports through from target two sides probe, based a long-theorized accumulation at crown (i.e. top) plasma. The patterns...
A novel multicode workflow to interpret collector probe deposition patterns in DIII-D has been developed. The components of the consist a detailed computer-aided-design file vessel wall and scrape-off-layer (SOL) codes MAFOT, OSM, DIVIMP, 3DLIM. special-purpose toolkit enables passing output these among each other provide full-SOL picture impurity transport. demonstration is described support evidence near-SOL tungsten parallel accumulation during trace W experiments on DIII-D. Iteration...
First results are reported from the 3D Monte Carlo far-SOL impurity transport code 3DLIM. Tungsten deposition profiles measured on a Collector Probe (CP) located in near outer midplane, OMP, during W tracer experiments DIII-D reproduced by Radial replicated showing effect that decrease connection length CP to nearest wall contact point has probe, as well of assuming purely diffusive vs convective radial transport. For transport, diffusion coefficient 10 m2/s best reproduces patterns both...
High-Z impurities released from plasma-material interactions have been shown to limit the performance of fusion plasmas, and understanding these impurity transport mechanisms throughout plasma scrape-off layer is a major challenge. Presented herein study tungsten (W) erosion by uniquely measuring absolute quantities isotopic W in order determine source natural enriched 182W isotopes that traveled tokamak discharges on DIII-D National Fusion Facility at General Atomics. Two primary analysis...
Experimental results from the 2022 tungsten (W)-coated Small Angle Slot (SAS-VW) divertor campaign at DIII-D coupled with interpretive 3DLIM modelling show opposing trends for core impurity content when compared to deposition on far-Scrape Off Layer (SOL) Collector Probes (CPs) increasing main ion density. SAS-VW is a closed, W-coated designed more easily facilitate detachment while reducing leakage. An experiment performed series of upper-single-null L-mode discharges in each toroidal...
A dual collector probe system has been implemented on DIII-D for scrape-off-layer (SOL) impurity transport studies. These experiments injected isotopically enriched methane (13CD4) and sampled the impurities from this extrinsic, primary source with graphite probes at outboard midplane crown of upper single null L-mode plasmas. Using a stable isotopic mixing model, results suggest that 13C injections prior to these built up walls act as secondary, intrinsic probes. This secondary accounts...
Metal powders are a fundamental starting point for fabricating many types of nuclear targets. Elemental powder properties can differ drastically between batches, even when using the same method. Therefore, variation in morphology and size metal cause variable quality produce inconsistent results with what otherwise proven target manufacturing techniques. Additive has additional requirements higher more uniform feedstock. The production spheroidized uniform, reproducible narrow distribution...