A5003602357- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Nuclear reactor physics and engineering
- Plasma Diagnostics and Applications
- Solar and Space Plasma Dynamics
- Nuclear Physics and Applications
- Laser-induced spectroscopy and plasma
- Dark Matter and Cosmic Phenomena
- Atomic and Molecular Physics
- Physics of Superconductivity and Magnetism
- Dust and Plasma Wave Phenomena
- Nuclear Engineering Thermal-Hydraulics
- Metal and Thin Film Mechanics
- Neural Networks and Applications
- Quantum, superfluid, helium dynamics
- Nuclear Materials and Properties
- Radiation Detection and Scintillator Technologies
- Non-Destructive Testing Techniques
- Particle physics theoretical and experimental studies
- Salmonella and Campylobacter epidemiology
- Machine Learning and ELM
Texas A&M University
2025
General Atomics (United States)
2016-2024
Williams (United States)
2017
University of California, San Diego
2017
Oak Ridge Associated Universities
2016-2017
Oak Ridge Institute for Science and Education
2017
William & Mary
2017
University of California, Los Angeles
2017
Princeton Plasma Physics Laboratory
2012-2017
Lawrence Livermore National Laboratory
2017
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...
Extensive modelling efforts of the plasma response to resonant magnetic perturbation fields, utilized for controlling edge localized mode (ELM), help identify edge-peeling as a key factor, which correlates observed ELM mitigation in several tokamak devices, including MAST, ASDEX Upgrade, EAST, and HL-2A. The recently safety factor window HL-2A experiments is explained terms response. computed response, based on toroidal single fluid resistive model with different assumption flows, found...
Experiments have been executed in the DIII-D tokamak to extend suppression of Edge Localized Modes (ELMs) with Resonant Magnetic Perturbations (RMPs) ITER-relevant levels beam torque. The results support hypothesis for RMP ELM based on transition from an ideal screened response a tearing at resonant surface that prevents expansion pedestal unstable width [Snyder et al., Nucl. Fusion 51, 103016 (2011) and Wade 55, 023002 (2015)]. In ITER baseline plasmas I/aB = 1.4 ν* ∼ 0.15, ELMs are readily...
Varying the neutral beam injection (NBI) mix reveals a clear pedestal-top rotation threshold for edge localized mode (ELM) suppression by resonant magnetic perturbations (RMPs). Guided expectations RMP penetration mechanism, is found to correspond critical radius zero-crossing. No such observed electron perpendicular amount and ratio of power in different NBI source geometries (termed mix) also that can be crossed at widely varying total injected torques. Computing local torque density edge,...
An integrated model for the ionization, radiation, and advection of impurities in extended-magnetohydrodynamic code M3D-C1 is described. This implementation makes use KPRAD model, which calculates bremsstrahlung radiation impurity recombination, rates using a density each charge state advanced separately. The presented here allows independent evolution electron ion temperatures, necessary to accurately cases where temperature drops more quickly than electron–ion thermal equilibration time....
The entry of drug-resistant Salmonella enterica into the food supply is a challenge to public health and safety. One emerging concern role synanthropic insects for moving microbial pathogens throughout poultry production systems, where commonly thrive. We investigated presence phenotypic antimicrobial susceptibility S. from insect environmental samples broiler farms. Insects were collected house adjacent compost barn. Environmental (poultry feed, drinking water, fresh litter, feces)...
Abstract The nature of the multi-modal n = 2 plasma response and its impact on global confinement is studied as a function axisymmetric equilibrium pressure, edge safety factor, collisionality, L-versus H-mode conditions. Varying relative phase ( <?CDATA $\Delta {{\phi}_{\text{UL}}}$ ?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mstyle displaystyle="false"> <mml:mi mathvariant="normal">Δ</mml:mi> <mml:msub> <mml:mrow> <mml:mi>ϕ</mml:mi> </mml:mrow>...
Abstract Nonlinear 3D MHD simulations of shattered-pellet injection (SPI) in JET show prototypical SPI-driven disruptions using the M3D-C1 and NIMROD extended-MHD codes. Initially, radiation-driven thermal quenches are accelerated by activity as pellet crosses rational surfaces, leading to a radiation spike, global stochasticization magnetic field, complete quench. Eventually, current quenches, preceded spike seen Ohmic heating becomes equal radiative cooling. The results qualitatively...
A verification benchmark has been carried out between the M3D-C1 and NIMROD extended-magnetohydrodynamic codes for simulations of impurity-induced disruption mitigation. Disruptions are a significant concern future tokamaks high-fidelity required in order to ensure success mitigation techniques (e.g. shattered-pellet injection) large-scale fusion reactors. Both magnetohydrodynamic (MHD) have coupled Killer Pellet RADiation code impurity dynamics. The show excellent agreement four...
On DIII-D, the high scenario has an internal transport barrier (ITB), , and very normalized confinement . Recently, plasmas starting with these conditions have been dynamically driven to where we find ITB performance persist for five energy times. These are projected meet ITER steady-state goal of Q = 5. The is maintained at lower a strong reverse shear, consistent predictions that negative central shear can threshold ITB. There two observed states in scenario: H-mode state edge pedestal,...
Abstract Recent dedicated DIII-D experiments in low-torque, ITER-similar-shape (ISS) hydrogen plasmas (at a plasma current I p ∼ 1.5 MA and ITER-similar edge safety factor q 95 3.6) show that the L-H transition power threshold P LH can be reduced substantially (∼30%) with L-mode helium admixtures n He / e ⩽ 25%. In ensuing H-mode, ion fractions H remain below H-mode normalized pressure confinement quality are only slightly affected by seeding, Z eff 2.15 (including carbon content). The...
The STEP (Stability, Transport, Equilibrium, and Pedestal) integrated-modeling tool has been developed in OMFIT to predict stable, tokamak equilibria self-consistently with core-transport pedestal calculations. couples theory-based codes integrate a variety of physics, including magnetohydrodynamic stability, transport, equilibrium, formation, current-drive, heating, fueling. input/output each code is interfaced centralized ITER-Integrated Modelling & Analysis Suite data structure,...
Abstract This paper deals with resistive wall tearing mode (RWTM) disruptions. RWTMs are closely related to modes. modes whose linear and nonlinear behavior is strongly dependent on the outside plasma. The consequence for ITER, that thermal quench timescale could be much longer than previously conjectured. Active feedback stabilization another possible way mitigate or prevent RWTM Simulations of disruptions reviewed DIII-D MST. MST has a time not observed experimentally when operated as...
We use the 3D magnetohydrodynamic (MHD) code M3D-C1 [Jardin et al., Comput. Sci. Discovery 5, 014002 (2012)] to examine MHD stability and subsequent evolution of NSTX shot 129169. This discharge had a period with non-monotonic safety factor profile, q (reversed shear), which was terminated by event that abruptly lowered central factor, q0, greatly reduced peakedness pressure profile. show equilibrium just before occurred linearly unstable many pressure-driven infernal modes. Modes toroidal...
Abstract A new fluid model for runaway electron (RE) simulation based on description is introduced and implemented in the magnetohydrodynamics (MHD) code M3D-C1, which includes self-consistent interactions between plasma REs. The utilizes method of characteristics to solve continuity equation RE density with large convection speed, uses a modified Boris algorithm pseudo particle pushing. was employed simulate MHD instabilities happening final loss event DIII-D tokamak. Nonlinear reveals that...
A high-level design study for a new experimental tokamak shows that advances in fusion science and engineering can be leveraged to narrow the gaps energy confinement exhaust power handling remain between present devices future pilot plant (FPP). This potential U.S. facility, an Exhaust Confinement Integration Tokamak Experiment (EXCITE), will access operational space close projected FPP performance regime via compact, high-field, high-power-density approach utilizes advanced scenarios...
The 3D fluid-plasma edge transport code EMC3-EIRENE is used to test several magnetic field models with and without plasma response against DIII-D experimental data for even odd-parity n = 3 perturbations. include ideal extended MHD equilibria, the vacuum approximation. Plasma required reduce stochasticity in pedestal region even-parity fields, however too much screening suppresses measured splitting of downstream Te profile. Odd-parity perturbations result weak tearing only small additional...
Abstract The effect of the axisymmetric plasma shape on non-axisymmetric response to resonant magnetic perturbations is investigated in experiment and modeling for DIII-D, EAST ASDEX Upgrade tokamaks. Systematically triangularity, whilst keeping other equilibrium quantities largely unchanged, reveals that strongly suppressed at high triangularity compared low triangularity. This validated through targeted comparison with experiments EAST, Upgrade. DIII-D measurements are used validate...
The OMFIT STEP (Meneghini et al. , Nucl. Fusion vol. 10, 2020, p. 1088) workflow has been used to develop inductive and steady-state H-mode core plasma scenario use cases for a $B_0 = 8 \, {\rm T}$ $R_0 4 m}$ machine help guide inform future higher-fidelity studies of transport confinement in compact tokamak reactors. Both are designed produce 200 MW or more net electric power an up-down symmetric with minor radius $a 1.4 elongation $\kappa 2.0$ triangularity $\delta 0.5$ effective charge...
In order to understand the effect of rotation on response a plasma three-dimensional magnetic perturbations, we perform systematic scan zero-crossing profile in DIII-D ITER-similar shape equilibrium using linear, time-independent modeling with M3D-C1 extended magnetohydrodynamics code. We confirm that local resonant field generally increases as decreases at rational surface. Multiple peaks are observed near surfaces, however, and maximum does not always correspond zero Furthermore, show...
An integrated-modeling workflow has been developed for the purpose of performing predict-first analysis transient-stability experiments. Starting from an existing equilibrium reconstruction a past experiment, couples together EFIT Grad-Shafranov solver [L. Lao et al., Fusion Sci. Technol. 48, 968 (2005)], EPED model pedestal structure [P. B. Snyder Phys. Plasmas 16, 056118 (2009)], and NEO drift-kinetic-equation [E. A. Belli J. Candy, Plasma Controlled 54, 015015 (2012)] (for bootstrap...
Verification of continuum solutions to the electron and ion drift kinetic equations (DKEs) in NIMROD [C. R. Sovinec et al., J. Comp. Phys. 195, 355 (2004)] is demonstrated through comparison with several neoclassical transport codes, most notably NEO [E. A. Belli Candy, Plasma Controlled Fusion 54, 015015 (2012)]. The DKE use NIMROD's spatial representation, 2D finite-elements poloidal plane a 1D Fourier expansion toroidal angle. For velocity space, novel finite elements applied for pitch...
Abstract This paper investigates the predictive capabilities of TGYRO and TGLF models in assessing performance negative triangularity (NT) plasmas compared to positive (PT) fusion devices. predicts kinetic profiles, while analyzes turbulent transport. The study reveals that reasonably NT profiles similar PT, although it overpredicts high-power scenarios where there is increased experimental MHD activity. analysis finds reduced linear growth rates altered flux spectra relative PT....