A5021004394- Magnetic confinement fusion research
- Superconducting Materials and Applications
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Ionosphere and magnetosphere dynamics
- Nuclear reactor physics and engineering
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Atomic and Molecular Physics
- Nuclear physics research studies
- Muon and positron interactions and applications
- Nuclear Physics and Applications
- Solar and Space Plasma Dynamics
- Inertial Sensor and Navigation
- Modeling and Simulation Systems
- X-ray Spectroscopy and Fluorescence Analysis
- Ion-surface interactions and analysis
- Non-Destructive Testing Techniques
- Advanced Radiotherapy Techniques
- Rare-earth and actinide compounds
- Advancements in Photolithography Techniques
- Geomagnetism and Paleomagnetism Studies
- Magnetic Field Sensors Techniques
- Atomic and Subatomic Physics Research
- High-pressure geophysics and materials
Aalto University
2012-2025
Max Planck Institute for Plasma Physics
2024
Tokamak Energy (United Kingdom)
2016-2023
Royal Military Academy
2020
Culham Science Centre
2017
VTT Technical Research Centre of Finland
2014
Tekes
2008-2014
Japan Atomic Energy Agency
2009
Abstract The most efficient and promising operational regime for the International Thermonuclear Experimental Reactor tokamak is high-confinement mode. In this regime, however, periodic relaxations of plasma edge can occur. These edge-localized modes pose a threat to integrity fusion device. Here we reveal strong impact energetic ions on spatio-temporal structure in tokamaks using nonlinear hybrid kinetic–magnetohydrodynamic simulations. A resonant interaction between fast at electromagnetic...
The 2014–2016 JET results are reviewed in the light of their significance for optimising ITER research plan active and non-active operation. More than 60 h plasma operation with first wall materials successfully took place since its installation 2011. New multi-machine scaling type I-ELM divertor energy flux density to is supported by principle modelling. relevant disruption experiments modelling reported a set three mitigation valves mimicking setup. Insights L–H power threshold Deuterium...
Tokamak Energy Ltd, UK, is developing spherical tokamaks using high temperature superconductor magnets as a possible route to fusion power relatively small devices. We present an overview of the development programme including details enabling technologies, key modelling methods and results, remaining challenges on path compact fusion.
Abstract For the past several years, JET scientific programme (Pamela et al 2007 Fusion Eng. Des . 82 590) has been engaged in a multi-campaign effort, including experiments D, H and T, leading up to 2020 first with 50%/50% D–T mixtures since 1997 ever plasmas ITER mix of plasma-facing component materials. this purpose, concerted physics technology was launched view prepare campaign (DTE2). This paper addresses key elements developed by directly contributing preparation. intense preparation...
Abstract Ion temperatures of over 100 million degrees Kelvin (8.6 keV) have been produced in the ST40 compact high-field spherical tokamak (ST). excess 5 keV not previously reached any ST and only obtained much larger devices with substantially more plasma heating power. The corresponding fusion triple product is calculated to be <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>n</mml:mi> <mml:mi>i</mml:mi> <mml:mn>0</mml:mn>...
Abstract ST40 is a compact, high-field ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>B</mml:mi> <mml:mi mathvariant="normal">T</mml:mi> <mml:mn>0</mml:mn> </mml:mrow> </mml:msub> <mml:mtext>⩽</mml:mtext> <mml:mn>2.1</mml:mn> <mml:mstyle scriptlevel="0"/> <mml:mtext>T</mml:mtext> </mml:math> ) spherical tokamak (ST) with mission to expand the physics and technology basis for ST route commercial fusion. The research programme covers...
Collective Thomson scattering (CTS) experiments were carried out at ASDEX Upgrade to measure the one-dimensional velocity distribution functions of fast ion populations. These measurements are compared with simulations using codes TRANSP/NUBEAM and ASCOT for two different neutral beam injection (NBI) configurations: NBI sources only one source. The measured CTS spectra as well inferred clearly asymmetric a consequence anisotropy populations selected geometry experiment. As expected, one-beam...
Abstract Experiments on ASDEX Upgrade (AUG) in 2021 and 2022 have addressed a number of critical issues for ITER EU DEMO. A major objective the AUG programme is to shed light underlying physics confinement, stability, plasma exhaust order allow reliable extrapolation results obtained present day machines these reactor-grade devices. Concerning pedestal physics, mitigation edge localised modes (ELMs) using resonant magnetic perturbations (RMPs) was found be consistent with reduction linear...
The Alfvén instability nonlinearly excited the energetic-particle-driven geodesic acoustic mode on ASDEX-Upgrade tokamak, as demonstrated experimentally. mechanism of excitation and nonlinear evolution is not yet fully understood. In present work, a first-principles simulation using MEGA code investigated properties in both linear growth saturated phases. Here we show that successfully reproduced coexistence these two modes, agreed with experimental results well. Conclusive evidence showed...
Abstract On the basis of several recent breakthroughs in fusion research, many activities have been launched around world to develop power plants on fastest possible time scale. In this context, high-fidelity simulations plasma behavior large supercomputers provide one main pathways accelerating progress by guiding crucial design decisions. When it comes determining energy confinement a magnetic device, which is key quantity interest, gyrokinetic turbulence are considered approach choice –...
A strong toroidal rotation braking has been observed in plasmas with application of an n = 1 magnetic perturbation field on the JET tokamak. Calculation results from momentum transport analysis show that torque induced by a global profile. The maximal value this is at plasma core region (ρ < 0.4) and it about half neutral beam injection torque. calculation shows mainly regime core, but close to transition between 1/ν regimes. neoclassical viscosity (NTV) regimes calculated. magnitude NTV...
The wall loads due to fusion alphas as well neutral beam injection- and ICRF-generated fast ions were simulated for ITER reference scenario-2 scenario-4 including the effects of ferritic inserts (FIs), test blanket modules (TBMs), 3D with two limiter structures. simulations carried out using Monte Carlo guiding-centre orbit-following code ASCOT. FIs found very effective in ameliorating detrimental toroidal ripple: ion are reduced practically their negligible axisymmetric level. thermonuclear...
The impact of edge localized modes (ELMs) and externally applied resonant non-resonant magnetic perturbations (MPs) on fast-ion confinement/transport have been investigated in the ASDEX Upgrade (AUG), DIII-D KSTAR tokamaks.Two phases with respect to ELM cycle can be clearly distinguished ELM-induced losses.Inter-ELM losses are characterized by a coherent modulation plasma density around separatrix while intra-ELM appear as well-defined bursts.In high collisionality plasmas mitigated ELMs,...
Within the ITPA Topical Group on Energetic Particles, we have investigated impact that various mechanisms breaking tokamak axisymmetry can fusion alpha particle confinement in ITER as well wall power loads due to these alphas. In addition well-known TF ripple, 3D effect ferromagnetic materials (in ferritic inserts and test blanket modules) ELM mitigation coils are included mechanisms. scenario 4 was chosen since, its lower plasma current, it is more vulnerable for off-normal features. First,...
Abstract The ASDEX Upgrade (AUG) programme, jointly run with the EUROfusion MST1 task force, continues to significantly enhance physics base of ITER and DEMO. Here, full tungsten wall is a key asset for extrapolating future devices. high overall heating power, flexible mix comprehensive diagnostic set allows studies ranging from mimicking scrape-off-layer divertor conditions DEMO at density fully non-inductive operation ( q 95 = 5.5, ) low density. Higher installed electron cyclotron...
Abstract The non-resonant magnetic braking effect induced by a non-axisymmetric perturbation is investigated on JET and TEXTOR. collisionality dependence of the torque n = 1, where toroidal mode number, generated error field correction coils observed. observed located mainly in plasma core (normalized radius ρ < 0.4) increases with decreasing collisionality. neoclassical viscosity (NTV) collisionless regime modelled using numerical solution bounce-averaged drift kinetic equation....
Abstract Mitigating edge localized modes (ELMs) with resonant magnetic perturbations (RMPs) can increase energetic particle losses and resulting wall loads, which have previously been studied in the vacuum approximation. This paper presents recent results of fusion alpha NBI ion ITER baseline scenario modelled Monte Carlo orbit following code ASCOT a realistic field including effect plasma response. The response was found to reduce but losses, up 4.2% injected power being lost. Additionally,...
Abstract An overview of recent results obtained at the tokamak ASDEX Upgrade (AUG) is given. A work flow for predictive profile modelling AUG discharges was established which able to reproduce experimental H-mode plasma profiles based on engineering parameters only. In center, theoretical predictions current redistribution by a dynamo effect were confirmed experimentally. For core transport, stabilizing fast ion distributions turbulent transport shown be important explain isotope and...
Auxiliary heating such as neutral beam injection (NBI) and ion cyclotron resonance (ICRH) will accelerate ions in ITER up to energies the MeV range, i.e. which are also typical for alpha particles. Fast of any these populations elevate collective Thomson scattering (CTS) signal proposed CTS diagnostic ITER. It is interest determine contributions fast large Doppler shifts scattered radiation since conclusions can mostly be drawn dominant contributor. In this study, distribution functions...
Here we demonstrate a comprehensive comparison of collective Thomson scattering (CTS) measurements with steady-state Monte Carlo simulations performed the ASCOT and VENUS codes. The were taken at location on magnetic axis as well an off-axis location, using two projection directions each location. agree on-axis, but for geometries discrepancies are observed both directions. For near perpendicular direction respect to field, between measurement can be explained by uncertainty in plasma...
Abstract The Mega Ampère Spherical Tokamak (MAST) programme is strongly focused on addressing key physics issues in preparation for operation of ITER as well providing solutions DEMO design choices. In this regard, MAST has provided results understanding and optimizing H-mode confinement, operating with smaller edge localized modes (ELMs), predicting handling plasma exhaust tailoring auxiliary current drive. all cases, the high-resolution diagnostic capability complemented by sophisticated...
Abstract In tokamaks, a leading platform for fusion energy, periodic filamentary plasma eruptions known as edge-localized modes occur in plasmas with high-energy confinement and steep pressure profiles at the edge. These could damage tokamak wall but can be suppressed using small three-dimensional magnetic perturbations. Here we demonstrate that these perturbations change topology just inside gradient region of We identify signatures island, their observation is linked to suppression modes....