A5026256875- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Inorganic Fluorides and Related Compounds
- Inorganic Chemistry and Materials
- Plasma Diagnostics and Applications
- Adaptive optics and wavefront sensing
- Geophysics and Sensor Technology
- Renal and Vascular Pathologies
- Gas Dynamics and Kinetic Theory
- Space Exploration and Technology
- Fluid Dynamics and Turbulent Flows
- Computational Fluid Dynamics and Aerodynamics
- Simulation Techniques and Applications
- Geomagnetism and Paleomagnetism Studies
- Inertial Sensor and Navigation
- Atomic and Molecular Physics
- Distributed and Parallel Computing Systems
- Spacecraft and Cryogenic Technologies
- Guidance and Control Systems
- Numerical methods for differential equations
Princeton Plasma Physics Laboratory
2022-2025
Massachusetts Institute of Technology
2024
Princeton University
2018-2022
Plasma Technology (United States)
2021-2022
Fusion (United States)
2021-2022
Fusion Academy
2021-2022
University of Iowa
2022
General Atomics (United States)
2022
How predictable are life trajectories? We investigated this question with a scientific mass collaboration using the common task method; 160 teams built predictive models for six outcomes data from Fragile Families and Child Wellbeing Study, high-quality birth cohort study. Despite rich dataset applying machine-learning methods optimized prediction, best predictions were not very accurate only slightly better than those simple benchmark model. Within each outcome, prediction error was...
We present new stellarator equilibria that have been optimized for reduced turbulent transport using nonlinear gyrokinetic simulations within the optimization loop. The routine involves coupling pseudo-spectral GPU-native code GX with equilibrium and DESC . Since allows fast simulations, we directly optimize heat fluxes. To handle noisy flux traces returned by these employ simultaneous perturbation stochastic approximation (SPSA) method only uses two objective function evaluations a simple...
Abstract The MANTA (Modular Adjustable Negative Triangularity ARC-class) design study investigated how negative-triangularity (NT) may be leveraged in a compact, fusion pilot plant (FPP) to take ‘power-handling first’ approach. result is pulsed, radiative, ELM-free tokamak that satisfies and exceeds the FPP requirements described 2021 National Academies of Sciences, Engineering, Medicine (NASEM) report ‘Bringing Fusion U.S. Grid’ (2021 Bringing Grid ). A self-consistent integrated modeling...
Turbulent transport is regarded as one of the key issues in magnetic confinement nuclear fusion, both for tokamaks and stellarators. In this work, we show that a significant decrease microstability-based proxy, opposed to geometric one, turbulent heat flux, namely quasilinear can be obtained an efficient manner by coupling stellarator optimization with linear gyrokinetic simulations. This accomplished computing flux at each step process, well deviation from quasisymmetry, minimizing their...
A quasi-linear reduced transport model is developed from a database of high- $\beta$ electromagnetic nonlinear gyrokinetic simulations performed with spherical tokamak for energy production (STEP) relevant parameters. The fully and accounts the effect equilibrium flow shear using novel approach. Its flux predictions are shown to agree quantitatively local across broad range STEP-relevant equilibria. This implemented in T3D solver that used perform first flux-driven STEP account hybrid...
Transport characteristics and predicted confinement are shown for the Infinity Two fusion pilot plant baseline plasma physics design, a high field stellarator concept developed using modern optimization techniques. predictions made fidelity nonlinear gyrokinetic turbulence simulations along with drift kinetic neoclassical simulations. A pellet fueled scenario is proposed that enables supporting an edge density gradient to substantially reduce ion temperature turbulence. Trapped electron mode...
The selection, design, and optimization of a suitable blanket configuration for an advanced high-field stellarator concept is seen as key feasibility issue has been incorporated vital necessary part the Infinity Two Fusion Pilot Plant (FPP) physics basis. focus this work was to identify baseline which can be rapidly deployed while also maintaining flexibility opportunities higher performing concepts later in development. Results from analysis indicate that gas-cooled solid breeder designs...
The magneto-hydrodynamic equilibrium and stability properties of the Infinity Two Fusion Pilot Plant baseline plasma physics design are presented. configuration is a four field period, aspect ratio A = 10 quasi-isodynamic stellarator optimized for excellent confinement at elevated density high magnetic B 9 T. Magnetic surfaces exist in core vacuum retain good surface integrity from to an operational β 1.6%, volume average pressures, corresponding 800 MW Deuterium-Tritium fusion operation....
We provide an assessment of the Infinity Two Fusion Pilot Plant (FPP) baseline plasma physics design. is a four-field period, aspect ratio A = 10, quasi-isodynamic stellarator with improved confinement appealing to max-J approach, elevated density and high magnetic fields (⟨ B ⟩ 9 T). At envisioned operating point [800 MW deuterium-tritium (DT) fusion], configuration has robust surfaces based on magnetohydrodynamic (MHD) equilibrium calculations stable both local global MHD instabilities....
In this work, we present a detailed assessment of fusion-born alpha-particle confinement, their wall loads, and stability Alfvén eigenmodes driven by these energetic particles in the Infinity Two Fusion Pilot Plant Baseline Plasma Design, 4-field-period quasiisodynamic stellarator to operate deuterium-tritium fusion conditions. Using Monte-Carlo codes SIMPLE, ASCOT5, KORC-T, study collisionless collisional dynamics guiding-center full-orbit alpha-particles core plasma. We find that energy...
We present algorithms and results from Gkeyll, a full-f continuum, electromagnetic gyrokinetic code, designed to study turbulence in the edge region of fusion devices. The is computationally very challenging, requiring robust that can handle large-amplitude fluctuations stable interactions with plasma sheaths. an energy-conserving high-order discontinuous Galerkin scheme solves equations Hamiltonian form. Efficiency improved by careful choice basis functions automatically generated...
A quasi-linear reduced transport model is developed from a database of high-$\beta$ electromagnetic nonlinear gyrokinetic simulations performed with Spherical Tokamak for Energy Production (STEP) relevant parameters. The fully and accounts the effect equilibrium flow shear using novel approach. Its flux predictions are shown to agree quantitatively local across broad range STEP-relevant equilibria. This implemented in T3D solver that used perform first flux-driven STEP account hybrid-KBM...
First-principles simulations of tokamak turbulence have proven to be great value in recent decades. We develop a pseudo-spectral velocity formulation the equations that smoothly interpolates between highly efficient but lower resolution three-dimensional (3-D) gyrofluid representation and conventional more expensive 5-D gyrokinetic representation. Our is projection nonlinear equation onto Laguerre–Hermite velocity-space basis. discuss issues related collisions, closures entropy. While any...
GX is a code designed to solve the nonlinear gyrokinetic system for low-frequency turbulence in magnetized plasmas, particularly tokamaks and stellarators. In GX, our primary motivation target fast solver that can be used fusion reactor design optimization along with wide-ranging physics exploration. This has led several algorithm decisions, specifically chosen prioritize time solution. First, we have discretization pseudospectral entire phase space, including Laguerre–Hermite formulation of...
We present an energy-conserving discontinuous Galerkin scheme for the full- $f$ electromagnetic gyrokinetic system in long-wavelength limit. use symplectic formulation and solve directly $\unicode[STIX]{x2202}A_{\Vert }/\unicode[STIX]{x2202}t$ , inductive component of parallel electric field, using a generalized Ohm’s law derived from equation. Linear benchmarks are performed to verify implementation show that avoids Ampère cancellation problem. perform nonlinear simulation helical...
Abstract The mission of the low aspect ratio spherical tokamak NSTX-U is to advance physics basis and technical solutions required for optimizing configuration next-step steady-state fusion devices. will ultimately operate at up 2 MA plasma current 1 T toroidal field on axis 5 s, has available 15 MW neutral beam injection power different tangency radii 6 high harmonic fast wave heating. With these capabilities develop understanding control tools ramp-up sustain performance fully...
A conservative discontinuous Galerkin scheme for a nonlinear Dougherty collision operator in full-f long-wavelength gyrokinetics is presented. Analytically this model has the advective-diffusive form of Fokker-Planck operators, it non-decreasing entropy functional, and conserves particles, momentum energy. Discretely these properties are maintained exactly as well, independent numerical resolution. In work phase space discretization performed using novel version scheme, carefully constructed...
Flux tube simulations of plasma turbulence in stellarators and tokamaks typically employ coordinates which are aligned with the magnetic field lines. Anisotropic turbulent fluctuations can be represented such field-aligned very efficiently, but resulting non-trivial boundary conditions involve all three spatial directions, must handled care. The standard "twist-and-shift" formulation [Beer, Cowley, Hammett \textit{Phys. Plasmas} \textbf{2}, 2687 (1995)] was derived assuming axisymmetry is...
The effect of neutral interactions on scrape-off layer (SOL) turbulence is investigated in a continuum gyrokinetic code that has been coupled to kinetic model transport. This extends the work previous paper [T. N. Bernard et al., Phys. Plasmas 9, 052501 (2022)], which compared two NSTX SOL simulations simple helical geometry, one with neutrals and without. former included electron-impact ionization, charge exchange, wall recycling. Here, case gyrokinetic-only simulation includes an effective...
We demonstrate that cross-field transport in the scrape-off layer (SOL) can be moderately increased by electromagnetic effects high-beta regimes, resulting a broader electron heat-flux width on endplates. This conclusion is taken from full-$f$ gyrokinetic simulations of helical SOL model roughly approximates National Spherical Torus Experiment (NSTX). The have been performed with Gkeyll code, which recently became first code to capability simulate turbulence open magnetic field lines sheath...
We present the first-of-its-kind coupling of a continuum full-f gyrokinetic turbulence model with 6D for kinetic neutrals, carried out using Gkeyll code. Our objective is to improve first-principle understanding role neutrals in plasma fueling, detachment, and their interaction edge profiles statistics. includes only atomic hydrogen incorporates electron-impact ionization, charge exchange, wall recycling. These features have been successfully verified analytical predictions benchmarked...
The confinement of heat in the core a magnetic fusion reactor is optimised using multidimensional optimisation algorithm. For first time such study, loss due to turbulence modelled at every stage first-principles nonlinear simulations which accurately capture turbulent cascade and large-scale zonal flows. utilise novel approach, with gyrofluid treatment small-scale drift waves gyrokinetic A simple near-circular equilibrium standard parameters chosen as initial condition. figure merit, power...
High-temperature superconducting (HTS) magnetic mirrors under development exploit strong fields with high mirror ratio to compress loss cones and enhance confinement may offer cheaper, more compact fusion power plant candidates. This new class of devices could exhibit largely unexplored interchange gradient-driven modes. Such instabilities, methods stabilize them, can be studied gyrokinetics, given the magnetization prevalence kinetic effects. Our focus here is (a) determine if oft-used...
A key uncertainty in the design and development of magnetic confinement fusion energy reactors is predicting edge plasma turbulence. An essential step overcoming this validation accuracy reduced turbulent transport models. Drift-reduced Braginskii two-fluid theory one such set equations that has for decades simulated boundary plasmas experiment, but significant questions exist regarding its predictive ability. To end, using a novel physics-informed deep learning framework, we demonstrate...