A5007082177- Magnetic confinement fusion research
- Superconducting Materials and Applications
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Ionosphere and magnetosphere dynamics
- Nuclear reactor physics and engineering
- Nuclear Physics and Applications
- Multiferroics and related materials
- Dust and Plasma Wave Phenomena
- Plasma Diagnostics and Applications
- Cardiovascular Function and Risk Factors
- Graphite, nuclear technology, radiation studies
- Characterization and Applications of Magnetic Nanoparticles
- Physics of Superconductivity and Magnetism
- Electromagnetic Launch and Propulsion Technology
- Magnetic and transport properties of perovskites and related materials
- Cardiac Imaging and Diagnostics
- Laser-induced spectroscopy and plasma
- Nuclear and radioactivity studies
- Medical Imaging Techniques and Applications
- Magneto-Optical Properties and Applications
- ZnO doping and properties
- Particle Accelerators and Free-Electron Lasers
Oak Ridge National Laboratory
2015-2025
General Atomics (United States)
2016-2024
National Transportation Research Center
2023
Princeton Plasma Physics Laboratory
2016
University of California, San Diego
2016
Osaka University
2014
One modeling framework for integrated tasks (OMFIT) is a comprehensive which has been developed to enable physics codes interact in complicated workflows, and support scientists at all stages of the cycle. The OMFIT development follows unique bottom-up approach, where design capabilities organically evolve progressive integration components that are required accomplish goals increasing complexity. provides workflow easily generating full kinetic equilibrium reconstructions constrained by...
Fusion whole device modeling simulations require comprehensive models that are simultaneously physically accurate, fast, robust, and predictive. In this paper we describe the development of two neural-network (NN) based as a means to perform snon-linear multivariate regression theory-based for core turbulent transport fluxes, pedestal structure. Specifically, find NN-based approach can be used consistently reproduce results TGLF EPED1 over broad range plasma regimes, with computational...
Accurate prediction of fusion performance in present and future tokamaks requires taking into account the strong interplay between core transport, pedestal structure, current profile, plasma equilibrium. An integrated modeling workflow capable calculating steady-state self-consistent solution to this strongly coupled problem has been developed. The leverages state-of-the-art components for collisional turbulent equilibrium stability. Testing against a DIII-D discharge shows that is robustly...
Abstract An integrated modeling workflow capable of finding the steady-state plasma solution with self-consistent core transport, pedestal structure, current profile, and equilibrium physics has been developed tested against a DIII-D discharge. Key features achieved core-pedestal coupled are its ability to account for transport impurities in self-consistently, as well use machine learning accelerated models structure turbulent physics. Notably, is implemented within One Modeling Framework...
Abstract Physics-based simulations project a compact net electric fusion pilot plant with nuclear testing mission is possible at modest scale based on the advanced tokamak concept, and identify key parameters for its optimization. These utilize new integrated 1.5D core-edge approach whole device modeling to predict performance by self-consistently applying transport, pedestal current drive models converge fully non-inductive stationary solutions, predicting profiles energy confinement given...
Cross-field diffusion of energetic ions by microturbulence is measured during neutral-beam injection into the DIII-D tokamak. Fast-ion D(alpha), neutron, and motional Stark effect measurements diagnose fast-ion distribution function. As expected for transport plasma turbulence, anomalies relative to classical prediction are greatest in high temperature plasmas, at low energy, larger minor radius. Theoretical estimates comparable experimental levels.
Recent progress on ITER steady-state (SS) scenario modelling by the ITPA-IOS group is reviewed. Code-to-code benchmarks as IOS group's common activities for two SS scenarios (weak shear and internal transport barrier scenario) are discussed in terms of transport, kinetic profiles, heating current drive (CD) sources using various codes. Weak magnetic integrate plasma core edge combining a theory-based model (GLF23) with scaled experimental boundary profiles. The profiles (at normalized radius...
Since its inception in 2002, the International Tokamak Physics Activity topical group on Integrated Operational Scenarios (IOS) has coordinated experimental and modelling activity development of advanced inductive scenarios for applications ITER tokamak. The physics basis prospects have been significantly during that time, especially with respect to results. principal findings this research are as follows. Inductive capable higher normalized pressure (βN ⩾ 2.4) than baseline scenario = 1.8)...
We review progress made on the advanced tokamak path to fusion energy by DIII-D National Fusion Facility (Luxon et al. in Nucl 42:614, 2002). The represents a highly attractive approach for future steady state power plant. In this concept, there is natural alignment between high pressure operation, favorable stability and transport properties, self-driven ('bootstrap') plasma current sustain operation efficiently without disruptions. Research has identified several promising configurations...
Results from experiments on DIII-D [J. L. Luxon, Fusion Sci. Technol. 48, 828 (2005)] aimed at developing high β steady-state operating scenarios with high-qmin confirm that fast-ion transport is a critical issue for advanced tokamak development using neutral beam injection current drive. In DIII-D, greater than 11 MW of heating power applied the intent maximizing βN and noninductive However, in qmin>2 target typical range q95= 5–7 used next-step reactor models, Alfvén eigenmodes...
Abstract Time-dependent SOLPS-ITER simulations have been used to identify reduced models with the sparse identification of nonlinear dynamics (SINDy) method and develop model-predictive control boundary plasma state using main ion gas puff actuation. A series actuation sequences are input into produce a dynamic response in upstream divertor quantities. The SINDy is applied linear for electron density at outboard midplane <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Modification of the two existing DIII-D neutral beamlines is planned to allow vertical steering provide off-axis beam current drive (NBCD) peaked as far half plasma minor radius. New calculations for a downward-steered indicate strong with good localization so long toroidal magnetic field, B T , and current, I p point in same direction. This due alignment injection (NBI) local pitch field lines. model has been tested experimentally on by injecting equatorially mounted NBs into reduced size...
Recent studies on the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] have elucidated key aspects of dependence stability, confinement, and density control plasma magnetic configuration, leading to demonstration nearly noninductive operation for &gt;1 s with pressure 30% above ideal no-wall stability limit. Achieving fully requires high pressure, good through divertor pumping. Plasma geometry affects all these. Ideal magnetohydrodynamics modeling external kink suggests that it...
The DIII-D programme has recently initiated an effort to provide suitably scaled experimental evaluations of four primary ITER operational scenarios. New and unique features this work are that the plasmas incorporate essential scenarios anticipated operating characteristics; e.g. plasma cross-section, aspect ratio value I/aB discharges match design, with size reduced by a factor 3.7. Key aspects all scenarios, such as target values for βN H98, have been replicated successfully on DIII-D,...
A fusion development facility (FDF) based on the tokamak approach with normal conducting magnetic field coils is presented. FDF envisioned as a dual objective of carrying forward advanced (AT) physics and enabling energy applications. AT enables design compact steady-state machine moderate gain that can provide neutron fluence required for FDF's nuclear science objective. device offers uniquely viable path research in closing fuel cycle because demand to consume only quantity limited supply...
Energetic ion transport due to microturbulence is investigated in magnetohydrodynamic-quiescent plasmas by way of neutral beam injection the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)]. A range on-axis and off-axis scenarios are employed vary relevant parameters such as character background value Eb/Te, where Eb energetic energy Te electron temperature. In all cases, it found that any enhancement too small observe experimentally. These effects modeled using numerical analytic...
Helicon waves have been recently proposed as an off-axis current drive actuator for DIII-D, FNSF, and DEMO tokamaks. Previous ray tracing modeling using GENRAY predicts strong single pass absorption in the mid-radius region on DIII-D high beta tokamak discharges. The full wave code AORSA, which is valid to all order of Larmor radius can resolve arbitrary ion cyclotron harmonics, has used validate technique. If scrape-off-layer (SOL) ignored modeling, AORSA agrees with both amplitude location...
Understanding the physics of onset and evolution tearing modes (TMs) in tokamak plasmas is crucial for high-performance steady-state operations. The condition (m,n) = (2,1) stability, Δ′&gt;Δc′&gt;0, has been studied DIII-D hybrid discharges with accurate equilibrium reconstruction well-measured plasma profiles. Here, m poloidal mode number n toroidal number. n=1 TMs carefully identified using Mirnov array to determine in-phase signals time electron cyclotron emission measurements...
Theory-based integrated modeling validated against DIII-D experiments predicts that fully non-inductive operation with βN > 4.5 is possible certain upgrades. IPS-FASTRAN a new iterative numerical procedure integrates models of core transport, edge pedestal, equilibrium, stability, heating, and current drive self-consistently to find steady-state (d/dt = 0) solutions reproduces most features high discharges stationary profile. Projecting forward scenarios on future upgrades, the qmin 2...
The compact (R0~1.2-1.3m) Fusion Nuclear Science Facility (FNSF) is aimed at providing a fully integrated, continuously driven fusion nuclear environment of copious neutrons. This facility would be used to test, discover, and understand the complex challenges plasma material interactions, tritium fuel management, power extraction. Such properly designed provide, initially JET-level pressure (~30%T2) conditions (e.g., Hot-Ion H-Mode, Q<1)), an outboard neutron flux 0.25 MW/m2 while requiring...
The hybrid regime with beta, collisionality, safety factor and plasma shape relevant to the ITER steady-state mission has been successfully integrated ELM suppression by applying an odd parity n = 3 resonant magnetic perturbation (RMP). Fully non-inductive hybrids in DIII-D tokamak high beta ( ⩽ 2.8%) confinement (H98y2 1.4) similar have achieved zero surface loop voltage for up two current relaxation times using efficient central drive from ECCD NBCD. RMP causes surprisingly little increase...
On DIII-D (Luxon 2005 Fusion Sci. Technol. 48 828), a high β scenario with minimum safety factor (qmin) near 1.4 has been optimized new tools and shown to be favourable candidate for long pulse or steady state operation in future devices. The capability redirect up 5 MW of neutral beam injection (NBI) from on- off-axis improves the ability sustain elevated qmin less peaked pressure profile. These changes increase ideal magnetohydrodynamics (MHD) n = 1 mode βN limit thus providing path...
Transport modeling of a proposed ITER steady-state scenario based on DIII-D high poloidal-beta () discharges finds that ITB formation can occur with either sufficient rotation or negative central shear q-profile. The is characterized by large bootstrap current fraction (80%) which reduces the demands external drive, and radius internal transport barrier associated excellent normalized confinement. Modeling predictions electron in improve as approaches levels similar to typical existing...
Neutral beam current drive (NBCD) experiments in DIII-D using vertically shifted plasmas to move the away from axis have clearly demonstrated robust off-axis NBCD. Time-dependent measurements of magnetic field pitch angles by motional Stark effect diagnostic are used obtain evolution poloidal flux, which indicates a broad NBCD profile with peak at about half plasma minor radius. In most cases, measured is consistent calculations an orbit-following Monte Carlo code for ion slowing down...