A5022435324- Magnetic confinement fusion research
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Nuclear reactor physics and engineering
- Model Reduction and Neural Networks
- Superconducting Materials and Applications
- Gaussian Processes and Bayesian Inference
- Plasma Diagnostics and Applications
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Advanced Memory and Neural Computing
- Impact of Light on Environment and Health
- Political Dynamics in Latin America
- Traffic control and management
- Mexican Socioeconomic and Environmental Dynamics
- Vehicle emissions and performance
- Youth, Politics, and Society
- Neural Networks Stability and Synchronization
- Nuclear Materials and Properties
- Neural Networks and Applications
- Traffic Prediction and Management Techniques
- Advanced Measurement and Detection Methods
- High-pressure geophysics and materials
- Statistical Mechanics and Entropy
- Aerodynamics and Fluid Dynamics Research
Plasma Technology (United States)
2023-2024
Massachusetts Institute of Technology
2021-2024
Fusion Academy
2023-2024
Fusion (United States)
2023
Columbia University
2019-2021
Princeton Plasma Physics Laboratory
2021
ITER
2019-2020
Bariloche Atomic Centre
1991
Balseiro Institute
1991
• Reviews the fundamental physics aspects of first ITER W divertor and defines required operational lifetime within Staged Approach. Uses SOLPS simulation database to establish target peak heat flux neutral pressure burning plasma operating domain. Assesses consequences narrow SOL channels, fluid drifts, component shaping 3D magnetic fields for ELM control. recrystallization define an budget shows that fluxes ∼50% higher than previously assumed may be acceptable. Shows Ne N should equally...
We use a new gyrokinetic threshold model to predict bifurcation in tokamak pedestal width-height scalings that depends strongly on plasma shaping and aspect-ratio. The arises from the first second stability properties of kinetic-ballooning-modes yields wide narrow branches, expanding space accessible widths heights. branch offers potential for edge-localized-mode-free pedestals with high core pressure. For negative triangularity, low-aspect-ratio configurations are predicted give steeper...
Abstract This work examines H-mode and I-mode access on the SPARC tokamak, combining new simulations of core L-mode power balance with best empirical scalings available for L-H L-I thresholds. Scalings applied to first time include a novel projection based critical edge ion heat flux scaling derived from database metal-wall tokamaks. Doing this informs prospects device these regimes given set operational parameters, or potentially avoid them altogether. will seek high fusion energy gain Q in...
Abstract This work explores detailed power handling solutions for a class of high-field, highly-radiative negative triangularity (NT) reactors based around the MANTA concept (Rutherford et al 2024 Plasma Phys. Control. Fusion ). The divertor design is kept as simple possible, opting standard with leg length. FreeGS used to create an equilibrium boundary region, prioritizing short outer length only ∼50 cm (∼40% minor radius). UEDGE code package plasma solution track temperatures and fluxes...
Deposition and fuel retention profiles in low power hydrogen L-mode plasmas neon (Ne) seeded ITER DT burning have been investigated. Two different Ne plasma backgrounds with varying sub-divertor neutral pressures but the same impurity concentration are considered, representing high recycling partially detached divertor solutions. The 2D SOLPS numerical grid does not extend all way to wall surfaces so that an extrapolation of background is required performed using a second simulation stage...
Abstract This paper investigates the role of ionization on pedestal structure using both measurements and modeling for H-mode plasmas DIII-D Alcator C-Mod to enhance our ability predict behavior in future pilot plants. The impact neutral penetration depth density is investigated dimensionally matching hydrogen deuterium discharges at low high electron density. Lyman- α diagnostic show that neutrals penetrate deeper inside plasma field side, while similar isotopes. However, as opaqueness...
An encoder–decoder neural network has been used to examine the possibility for acceleration of a partial integro-differential equation, Fokker–Planck–Landau collision operator. This is part governing equation in massively parallel particle-in-cell code XGC, which study turbulence fusion energy devices. The emphasizes physics-inspired learning, where it taught respect physical conservation constraints operator by including them training loss, along with $\ell _2$ loss. In particular,...
We investigate the physics-constrained training of an encoder-decoder neural network for approximating Fokker-Planck-Landau collision operator in 5-dimensional kinetic fusion simulation XGC. To train this network, we propose a stochastic augmented Lagrangian approach that utilizes pyTorch's native gradient descent method to solve inner unconstrained minimization subproblem, paired with heuristic update penalty factor and Lagrange multipliers outer loop. Our results single ion species case,...
We present experimental inferences of cross-field impurity transport coefficients for Alcator C-Mod plasmas using a novel forward model the entire Ca K-alpha spectrum, including satellite lines within spectral range, to compare high-resolution X-ray Imaging Crystal Spectroscopy (XICS). These measurements are complemented by Extreme Ultra-Violet (EUV) spectroscopy that constrains closer edge. Using new atomic data sets both XICS and EUV analysis has enabled consideration line ratios across...
Abstract Transport in the DIII-D high confinement mode (H-mode) pedestal is investigated through a periodic edge gas puff modulation (GPM) which perturbs deuterium density and source profiles. By using absolutely calibrated experimental ionization profile measurements, radial profiles of diffusion ( D ) convection v are calculated into region without depending on modeling source. An analytic approach with closed-form expressions for more advanced Bayesian show evidence an inward particle...
At the high $n_{e}$ proposed for high-field fusion reactors, it is uncertain whether ionization, as opposed to plasma transport, will be most influential in determining at pedestal and separatrix. A database of Alcator C-Mod discharges analyzed evaluate impact source modification via cryopumping. The contains similarly-shaped H-modes fixed $I_{p} =$ 0.8 MA $B_{t} 5.4 T, spanning a large range $P_\mathrm{net}$ ionization. Measurements from an edge Thomson Scattering system are combined with...
Experimental measurements of plasma and neutral profiles across the pedestal are used in conjunction with 2D edge modeling to examine stiffness Alcator C-Mod H-mode plasmas. Experiments on observed degradation loss confinement below a critical value net power crossing separatrix, $P_\mathrm{net} = P_\mathrm{net}^\mathrm{crit} \approx 2.3$ MW. New analysis ionization particle flux reveal saturation electron density, $n_{e}^\mathrm{ped}$ despite continuous increases throughout pedestal,...
Fusion power plants require ELM-free, detached operation to prevent divertor damage and erosion. The separatrix operational space (SepOS) is proposed as a tool for identifying access the type-I ELM-free quasi-continuous exhaust regime. In this work, we recast SepOS framework using simple parameters present dedicated ASDEX Upgrade discharges demonstrate how interpret its results. Analyzing an extended database consisting of 6688 individual measurements, show that accurately describes H-mode...
An encoder-decoder neural network has been used to examine the possibility for acceleration of a partial integro-differential equation, Fokker-Planck-Landau collision operator. This is part governing equation in massively parallel particle-in-cell code, XGC, which study turbulence fusion energy devices. The emphasizes physics-inspired learning, where it taught respect physical conservation constraints operator by including them training loss, along with L2 loss. In particular, architectures...
We use a new gyrokinetic threshold model to predict bifurcation in tokamak pedestal width-height scalings that depends strongly on plasma shaping and aspect-ratio. The arises from the first second stability properties of kinetic-ballooning-modes yields wide narrow branches, expanding space accessible widths heights. branch offers potential for edge-localized-mode-free pedestals with high core pressure. For negative triangularity, low-aspect-ratio configurations are predicted give steeper...
Stability of a multilayered neural network architecture against synaptic changes has been studied numerically. We have found that the average change goes to zero as number N input neurons is N≫1. If fixed fraction output mistakes allowed, then synapses may be changed within some limits even for large N.