A5031858407- Magnetic confinement fusion research
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Laser-Plasma Interactions and Diagnostics
- Superconducting Materials and Applications
- Plasma Diagnostics and Applications
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Laser-induced spectroscopy and plasma
- Atomic and Molecular Physics
- Solar and Space Plasma Dynamics
- Particle Accelerators and Free-Electron Lasers
- Nuclear Materials and Properties
- Nuclear Physics and Applications
- Atomic and Subatomic Physics Research
- Astro and Planetary Science
- Radio Frequency Integrated Circuit Design
- Astronomical Observations and Instrumentation
- Antenna Design and Analysis
- Gas Dynamics and Kinetic Theory
- Diamond and Carbon-based Materials Research
- Microwave Engineering and Waveguides
- Spacecraft and Cryogenic Technologies
- Metal and Thin Film Mechanics
- Advanced Antenna and Metasurface Technologies
University of Wisconsin–Madison
2016-2025
Max Planck Institute for Plasma Physics
2014-2024
Max Planck Institute for Plasma Physics - Greifswald
2016-2023
Campbell Collaboration
2020-2022
University of Wisconsin System
2021
Universitat Politècnica de Catalunya
2019
Barcelona Supercomputing Center
2019
Max Planck Society
2014-2018
National Agency for New Technologies, Energy and Sustainable Economic Development
2016
University of Padua
2016
• 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...
Large Type-I edge localized modes (ELMs) are completely eliminated with small n = 3 resonant magnetic perturbations (RMP) in low average triangularity, , plasmas and ITER similar shaped (ISS) plasmas, relevant collisionalities . Significant differences the RMP requirements properties of ELM suppressed found when comparing two triangularities. In ISS current required to suppress ELMs is approximately 25% higher than triangularity plasmas. It also that width q95 window for suppression smaller...
Progress in the definition of requirements for edge localized mode (ELM) control and application ELM methods both high fusion performance DT operation non-active low-current ITER is described. Evaluation power fluxes low plasma current H-modes shows that uncontrolled ELMs will not lead to damage tungsten (W) divertor target, unlike high-current which by expected. Despite lack at lower currents, found be required under these conditions prevent an excessive contamination W, could eventually...
The EPED model predicts the H-mode pedestal height and width based upon two fundamental calculable constraints: (1) onset of non-local peeling-ballooning modes at low to intermediate mode number, (2) nearly local kinetic ballooning high number. We present detailed tests in discharges with edge localized (ELMs), employing new resolution measurements, finding good quantitative agreement across a range parameters. is then applied for first time quiescent (QH), similar level between predicted...
In this paper the manipulation of power deposition on divertor targets at DIII-D by application resonant magnetic perturbations (RMPs) for suppression large type-I edge localized modes (ELMs) is analysed. We discuss modification ELM characteristics RMP applied. It shown that width pattern in ELMy H-mode depends linearly deposited energy, whereas phase discharge those patterns are controlled externally induced perturbation. was also found heat transport due to small, plasma pedestal electron...
Recent DIII-D [J. L. Luxon et al., Nucl. Fusion 43, 1813 (2003)] experiments show a correlation between the extent of overlap magnetic islands induced in edge plasma by perturbation coils and complete suppression Type-I localized modes (ELMs) plasmas with ITER-like electron pedestal collisionality νe*∼0.1, flux surface shape low safety factor (q95≈3.6). With fixed amplitude n=3 resonant (RMP), ELM is obtained only finite window (q95) consistent maximizing component applied helical field....
Operating ITER in the reference inductive scenario at design values of Ip = 15 MA and QDT 10 requires achievement good H-mode confinement that relies on presence an edge transport barrier whose pedestal pressure height is key to plasma performance. Strong gradients occur such conditions can drive magnetohydrodynamic instabilities resulting localized modes (ELMs), which produce a rapid energy loss from region facing components (PFC). Without appropriate control, heat loads PFCs during ELMs...
Abstract The non-linear reduced four-field RMHD model in cylindrical geometry was extended to include plasma rotation, neoclassical poloidal viscosity and two fluid diamagnetic effects. Interaction of the static resonant magnetic perturbations (RMPs) with rotating plasmas tokamaks studied. self-consistent evolution equilibrium electric field due RMP penetration is taken into account model. It demonstrated that pedestal region steep pressure gradients, mean flows perpendicular field, which...
Abstract The EMC3‐Eirene code is improved in many aspects. Ad hoc boundary conditions for intrinsic impurities at the SOL‐core interface are removed by implicitly coupling to a 1D core model. Non‐uniform cross‐field transport coefficients allowed new version. A particle splitting technique implemented improving Monte Carlo statistic low‐temperature ranges of most interest. Domain splitting, which was possible toroidal direction only, now feasible all three directions, facilitating mesh...
The Wisconsin high-temperature superconductor axisymmetric mirror experiment (WHAM) will be a high-field platform for prototyping technologies, validating interchange stabilization techniques and benchmarking numerical code performance, enabling the next step up to reactor parameters. A detailed overview of experimental apparatus its various subsystems is presented. WHAM use electron cyclotron heating ionize build dense target plasma neutral beam injection fast ions, stabilized by...
Abstract Resilient divertor features connected to open chaotic edge structures in the Helically Symmetric eXperiment are investigated. For first time, an expanded vessel wall was considered that would give space for implementation of a physical target structure. The analysis done four different magnetic configurations with very plasma edges. A resilient interaction pattern identified across all configurations. This manifests as qualitatively similar footprint behavior equilibria. Overall,...
Abstract Since the publication of review Progress in ITER Physics Basis (PIPB) 2007, significant progress has been made understanding processes at plasma-material interface. This review, part ITPA Nuclear Fusion Special Issue On Path to Burning Plasma Operation , presents these developments, focusing on key areas such as physics plasma exhaust, interactions, and properties plasma-facing materials their evolution under exposure. The coordinated efforts Topical Group Scrape-Off Layer Divertor...
A study of three-dimensional (3D) perturbed magnetic field structures and transport for edge localized mode control experiments with resonant perturbations at DIII-D is presented. We focus on ITER-Similar Shape plasmas ITER relevant electron pedestal collisionalities . This performed in comparison results from TEXTOR-Dynamic Ergodic Divertor circular limiter plasmas. For both the structure analyzed vacuum paradigm—superimposing external RMP unperturbed equilibrium. TEXTOR L-mode this...
A comprehensive set of L–H transition experiments has been performed on DIII-D to determine the requirements for access H-mode plasmas in ITER's first (non-nuclear) operational phase with H and He second (activated) D plasmas. The power threshold, P TH , was evaluated different configurations auxiliary heating methods main ion species. Helium have significantly higher than deuterium at low densities all schemes, but similar as high except H-neutral beam injection-heated discharges, which are...
Recent experiments on JET have shown that type-I edge localized modes (ELMs) can be controlled by the application of static low n = 1 external magnetic perturbation fields produced four error field correction coils (EFCC) mounted far away from plasma between transformer limbs. When an with amplitude a few mT at (the normalized poloidal flux, ?, is larger than 0.95) applied during stationary phase ELMy H-mode plasma, ELM frequency rises ~30?Hz up to ~120?Hz. The energy loss per total stored...
A detailed experiment-theory comparison reveals that linear ideal MHD theory is in quantitative agreement with external magnetic and internal soft x-ray measurements of the plasma response to externally applied non-axisymmetric fields over a broad range beta rotation. This result represents significant step toward goal advancing understanding three-dimensional tokamak equilibria. Both show driven perturbation increases linearly perturbation, suggesting relevance models. The are made at...
Long-wavelength turbulence increases dramatically in the outer regions of DIII-D plasmas with application resonant magnetic field perturbations (RMPs) that suppress edge-localized modes (ELMs). Correspondingly, transport and global energy confinement decreases these low-collisionality RMP-ELM suppressed discharges. The core pedestal density are sharply reduced, while ion electron temperatures may change only slightly. Low wavenumber (k⊥ρi < 1) range 60–300 kHz, measured beam emission...
In-vessel, non-axisymmetric, control coils have proven to be an important option for mitigating and suppressing edge-localized modes (ELMs) in high performance operating regimes on a growing number of tokamaks. Additionally, in-vessel non-axisymmetric ELM coil is being considered the ITER baseline design. In preparing initial operation this set, comprehensive study was carried out characterize linear superposition 3D vacuum magnetic field, produced by coil, series equilibria representing...
Wendelstein 7-X (W7-X) is currently under commissioning in preparation for its initial plasma operation phase, phase 1.1 (OP1.1). This first serves primarily to provide an integral of all major systems needed operation, as well systems, such diagnostics, that need verify their foreseen functions. In OP1.1, W7-X will have a reduced set in-vessel components. particular, five graphite limiter stripes replace the later divertor. paper describes expected machine capabilities selection physics...
Abstract The fundamental behavior of the W7-X island divertor under detached conditions, which has been theoretically predicted with EMC3-Eirene code, is re-examined here experimental conditions achieved so far and compared first results. Both simulations experiments cover a range configurations plasma parameters, show following common trends: (1) rising impurity radiation, target heat load decreases ‘uniformly’ over entire surface in sense that both peak average loads can drop by an order...
Abstract Wendelstein 7-X (W7-X), the largest advanced stellarator, is built to demonstrate high power, performance quasi-continuous operation. Therefore, in recent campaign, experiments were performed prepare for long pulse operation, addressing three critical issues: development of stable detachment, control heat and particle exhaust, impact leading edges on plasma performance. The exhaust W7-X realized with help an island divertor, which utilizes large magnetic islands at boundary. This...
We show in experiments that a long, underdense, relativistic proton bunch propagating plasma undergoes the oblique instability, which we observe as filamentation. determine threshold value for ratio between transverse size and skin depth instability to occur. At threshold, outcome of experiment alternates filamentation self-modulation (evidenced by longitudinal modulation into microbunches). Time-resolved images density distribution reveal grows an observable level late along bunch,...
The magnetic-field perturbation produced by the dynamic ergodic divertor in TEXTOR changes topology of magnetic field plasma edge, creating an open chaotic system. spectrum contains only a few dominant harmonics and therefore it can be described analytical model. modeling is performed vacuum approximation without assuming backreaction does not rely on any experimentally obtained parameters. It shown that this predicts many details observed structure. Several experiments have been to prove...