A5055218170- Magnetic confinement fusion research
- Fusion materials and technologies
- Nuclear reactor physics and engineering
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Groundwater flow and contamination studies
- Hydrology and Watershed Management Studies
- Plasma Diagnostics and Applications
- Probabilistic and Robust Engineering Design
- Electrochemical Analysis and Applications
- Electrocatalysts for Energy Conversion
- Gaussian Processes and Bayesian Inference
- Fluid Dynamics and Turbulent Flows
- Particle accelerators and beam dynamics
- Hydrology and Sediment Transport Processes
- Numerical methods in inverse problems
- Model Reduction and Neural Networks
- Hydrological Forecasting Using AI
- Stability and Controllability of Differential Equations
- Cardiovascular Function and Risk Factors
- Image and Signal Denoising Methods
- Statistical and numerical algorithms
- Ionosphere and magnetosphere dynamics
- Advanced Control Systems Optimization
- Heat Transfer and Boiling Studies
Dutch Institute for Fundamental Energy Research
2016-2025
Institut de Recherche sur la Fusion par Confinement Magnétique
2024
CEA Cadarache
2024
Culham Science Centre
2024
Culham Centre for Fusion Energy
2024
Eindhoven University of Technology
2011-2023
École Polytechnique Fédérale de Lausanne
2023
Systems Technology (United States)
2021
University of Twente
2018
Vrije Universiteit Brussel
2014-2018
The plasma diagnostic and control (D&C) system for a future tokamak demonstration fusion reactor (DEMO) will have to provide reliable operation near technical physics limits, while its front-end components be subject strong adverse effects within the nuclear high temperature environment. ongoing developments ITER D&C represent an important starting point progressing towards DEMO. Requirements detailed exploration of are however pushing design using sophisticated methods aiming large spatial...
Future fusion reactors require a safe, steady-state divertor operation. With deep detachment, which is typically induced by impurity seeding, the radiation concentrates in small region at X-point or on closed flux surfaces above X-point. This so-called radiator (XPR) moves further inside confined with increasing seeding and location can be actively controlled. At AUG, parameter space for operation an XPR was significantly extended, using active feedback location. The observed nearly whole...
Abstract In magnetic confinement thermonuclear fusion the exhaust of heat and particles from core remains a major challenge. Heat leaving are transported via open field lines to region reactor wall, called divertor. Unabated, particle fluxes may become intolerable damage Controlled ‘plasma detachment’, regime characterized by both large reduction in plasma pressure temperature at divertor target, is required reduce onto Here we report systematic approach towards achieving this critical need...
Success of the UK’s Spherical Tokamak for Energy Production (STEP) programme requires a robust plasma control system. This system has to guide from initiation burning phase, maintain it there, produce desired fusion power duration and then terminate safely. be done in challenging environment with limited sensors without overloading plasma-facing components. The parameters operational regime STEP prototype will very different tokamaks, which are presently operation. During burn,...
Abstract We introduce LPMLE3, a new 1‐D approach to quantify vertical water flow components at streambeds using temperature data collected in different depths. LPMLE3 solves the partial differential equation for coupled and heat transport frequency domain. Unlike other approaches it does not assume semi‐infinite halfspace with location of lower boundary condition approaching infinity. Instead, uses local upper conditions. As such, streambed can be divided into finite subdomains bound top...
The oxygen evolution reaction (OER) has been identified as one of the performance-limiting processes in solar water splitting using photoelectrochemical (PEC) cells. One reasons for low OER performance is related to existence different types surface states at semiconductor–electrolyte interface: recombining (r-SS) and due intermediate species (i-SS). Since impact on still under debate, we investigate how affect PEC oxidation they experimental measurements. In a new computational approach,...
Abstract This paper presents the LPMLE n , a new method to estimate vertical flux and thermal diffusivity from streambed temperature time series using frequency domain. The main advantages of this are: (a) use multiple frequencies sensors for parameter estimation; (b) noise/uncertainty handling in an optimal way; (c) possibility parameters with both semi‐infinite bounded domain models; (d) compensation drifts data known as transients. capabilities are demonstrated synthetic field data,...
Abstract This work presents the use of a collisional-radiative model to infer plasma parameters from 2D emissivities several deuterium Balmer lines. The were obtained by MANTIS, an absolutely calibrated, ten-camera imaging polychromator with <?CDATA $< 5\,\mathrm{m}\mathrm{m}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mo><</mml:mo> <mml:mn>5</mml:mn> <mml:mspace width="0.17em" /> <mml:mi mathvariant="normal">m</mml:mi> </mml:math>...
Abstract In 2019 the UK launched Spherical Tokamak for Energy Production (STEP) programme to design and build a prototype electricity producing nuclear fusion power plant, aiming start operation around 2040. The plant should lay foundation development of commercial plants. is based on spherical tokamak principle, which opens route high pressure, steady state, operation. While facilitating state operation, introduces some specific plasma control challenges: (i) All current during burn phase...
Abstract Recently, experiments on basic plasma physics issues for solving future problems in fusion energy have been performed a Large Helical Device. There are several to be solved devices energy. Emerging burning are: alpha-channeling (ion heating by alpha particles), turbulence and transport electron dominant helium ash exhaust, reduction of the divertor heat load. To solve these problems, understanding (1) wave–particle interaction through (inverse) Landau damping, (2) characteristics...
Abstract In this paper we present a novel algorithm to extract the optical plasma boundary and radiation front for detached divertor plasmas. We show that reliable detection of leg is possible using lightweight image processing tools. Using non-tomographic approach, detected can be mapped poloidal plane. This approach fast accurate enough real-time control purposes, allowing in particular shape detachment control, post-shot physics dynamics analysis.
Abstract A multispectral camera setup is used to infer a 2D map of plasma parameters in tokamak from spectral emissions. However, the light measured by these cameras line integrated toroidal direction, whereas emissivities on poloidal plane are necessary for inference. The emissivity can be obtained tomographic reconstruction, but classical techniques too slow use real-time control. We present two machine learning based approaches accelerate reconstruction data setup. Both yield more...
The first generation of nuclear fusion reactors is expected to operate using a mixture deuterium (D) and tritium (T) fuel. Controlling the D:T ratio promising option control burn rate. Joint European Torus (JET), as only operational tokamak that can use tritium, uniquely placed test feasibility such control. Experiments carried out in 2023, during third JET D-T campaign, have demonstrated effective feedback under H-mode conditions. was measured visible spectroscopy injected via gas valves,...
Abstract Systematic extraction of locally valid dynamic models from experiments is necessary for controller design and the validation high fidelity models. This paper describes a model in form transfer function, giving response CIII (465.0 nm) emission front position to deuterium gas puffing TCV divertor during flattop, relevant heat exhaust control. The extracted using frequency data both SOLPS-ITER simulations perturbative experiments. We use steady-state solutions obtain an additional...
Current voltage curves and electrochemical impedance spectra (EIS) are crucial for investigating the performance limitations of cells. Therefore, we developed an approach which allows direct simulation such data based on microkinetic modeling. This us to assess influence various input parameters EIS current–voltage and, hence, overall We develop our oxygen evolution reaction (OER) taking place at semiconductor–electrolyte interface. At this interface, equations, that is, reactions, multiple...
Abstract The injection of electron cyclotron (EC) waves fulfills a number important tasks in nuclear fusion devices for which detailed knowledge the spatial power deposition profile is critical. This commonly determined using forward models such as beam or ray tracing. Recent numerical and experimental studies have shown that small-angle scattering EC it passes through turbulent plasma edge can cause significant broadening effective profile, leading to considerable underestimation width by...
Model predictive control (MPC) is promising for fueling and core density feedback in nuclear fusion tokamaks, where the primary actuators, frozen hydrogen fuel pellets fired into plasma, are discrete. Previous approaches have only approximated pellet injection as a continuous input due to complexity that it introduces. In this letter, we model plasma hybrid system propose two MPC strategies control: mixed-integer (MI) using conventional programming (MIP) solver utilizing our novel...
Abstract In this paper, we present the first results of a systematically designed multi-input multi-output gas-injection controller on Tokamak á Configuration Variable (TCV). We demonstrate simultaneous real-time control NII emission front position and line-integrated electron density using nitrogen deuterium gas injection. Injection and/or affects both density. This interplay between loops is termed interaction and, when strongly present, makes designing significantly more complex problem....
Abstract The successful operation of fusion reactors requires plasma scenarios with good core confinement and acceptable first wall heat loads that are stable robust to external perturbations. This poses both physical technological challenges. One the technologies addresses these challenges is a complex feedback control system supports advances in understanding helps ensure operating conditions. marginally plasmas often leads off-normal events (such as disruptions) can prevent some extent....
<title>Abstract</title> Nuclear fusion could offer clean, abundant energy. However, managing the power exhausted from core plasma towards reactor wall remains a major challenge, compounded in emerging compact designs promising more cost-effective pathways commercial Alternative Divertor Configurations (ADCs) are potential solution. In this work, ADC exhaust control is demonstrated for first time, employing novel method to diagnose neutral gas buffer which shields target. Our work on MAST-U...
Abstract iFLOW is a free, open‐source, and python‐based framework graphical user interface to visualize analyze temperature time series, extract one dimensional thermal velocity, v T , bulk effective diffusivity, k e . Information of properties the sediment‐water mixture (bulk) water allows quantifying one‐dimensional Darcian flux, q seepage from Available software packages were developed quantify only based on specific mathematical model or focused data processing parameter estimation...
Abstract This paper presents DIV1D, a new 1D dynamic physics-based model of the divertor plasma under development to study and control dynamics detached plasmas. An innovative feature DIV1D is that it mimics cross-field transport using an effective flux expansion includes neutral gas background outside leg. We outline mapping procedure for static 2D SOLPS-ITER simulations plasmas in Tokamak á Configuration Variable, which can be used benchmark codes. For good agreement found most important...
In this paper, a number of new approximations are introduced to estimate the perturbative diffusivity (χ), convectivity (V), and damping (τ) in cylindrical geometry. For purpose, harmonic components heat waves induced by localized deposition modulated power used. The based on semi-infinite slab equation. main result is approximation χ under influence V τ phase two harmonics making less sensitive calibration errors. To understand why can well geometry, relationships between transport models...