A5009510963- Magnetic confinement fusion research
- Superconducting Materials and Applications
- Fusion materials and technologies
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- High-Energy Particle Collisions Research
- Oceanographic and Atmospheric Processes
- Atomic and Subatomic Physics Research
- Nuclear Materials and Properties
- Anomaly Detection Techniques and Applications
- Quantum chaos and dynamical systems
- Laser-induced spectroscopy and plasma
- Fault Detection and Control Systems
- Metallurgical Processes and Thermodynamics
- Plasma Diagnostics and Applications
- Geomagnetism and Paleomagnetism Studies
- Particle Detector Development and Performance
- Russia and Soviet political economy
- Radiation Therapy and Dosimetry
Culham Science Centre
2015-2024
KTH Royal Institute of Technology
2013-2024
United Kingdom Atomic Energy Authority
2022-2024
Culham Centre for Fusion Energy
2021-2023
Royal Military Academy
2020
The STEP (Spherical Tokamak for Energy Production) Programme aims to deliver a UK prototype fusion energy plant, targeting 2040, and path commercial viability of fusion. To on this aim, we have performed initial scoping identify the design point spherical tokamak powerplant producing at least 100MWe net electric output that is self-sufficient in tritium production. We developed rapid workflow starts with systems code process develop an can then be iterated plasma codes jetto fiesta add...
Abstract STEP is a spherical tokamak prototype power plant that being designed to demonstrate net electric power. The design phase involves the exploitation of plasma models optimise fusion performance subject satisfying various physics and engineering constraints. A modelling workflow, including integrated core modelling, MHD stability analysis, SOL pedestal coil set free boundary equilibrium solvers, whole design, has been developed specify parameters develop viable scenarios. model JETTO...
STEP is a spherical tokamak prototype power plant that being designed to demonstrate net electric power. The design phase involves the exploitation of plasma models optimise fusion performance subject satisfying various physics and engineering constraints. A modelling workflow, including integrated core modelling, MHD stability analysis, SOL pedestal coil set free boundary equilibrium solvers, whole design, has been developed specify parameters develop viable scenarios. model JETTO used...
Abstract We present an overview of results from a series L–H transition experiments undertaken at JET since the installation ITER-like-wall (JET-ILW), with beryllium wall tiles and tungsten divertor. Tritium, helium deuterium plasmas have been investigated. Initial in tritium show ohmic transitions low density power threshold for ( P LH ) is lower than ones densities, while we still lack contrasted data to provide scaling high densities. In there notable shift which minimum <?CDATA...
Abstract The recent deuterium–tritium campaign in JET-ILW (DTE2) has provided a unique opportunity to study the isotope dependence of L-H power threshold an ITER-like wall environment (Be and W divertor). Here we present results from dedicated transition experiments at JET-ILW, documenting tritium plasmas, comparing them with matching deuterium hydrogen datasets. From earlier it is known that as plasma isotopic composition changes deuterium, through varying deuterium/hydrogen concentrations,...
Abstract JET experiments using the fuel mixture envisaged for fusion power plants, deuterium and tritium (D–T), provide a unique opportunity to validate existing D–T prediction capabilities in support of future device design operation preparation. The 2021 experimental campaign has achieved powers sustained over 5 s ITER-relevant conditions i.e. with baseline or hybrid scenario full metallic wall. In preparation campaign, extensive predictive modelling was carried out several assumptions...
Abstract In the initial stages of ITER operation, ELM mitigation systems need to be commissioned. This requires controlled flat-top operation in type-I ELMy H-mode regimes. Hydrogen or helium plasma discharges are used exclusively these ensure negligible production neutrons from fusion reactions. With expected higher L-H power threshold hydrogen and plasmas compared corresponding D D/T plasmas, it is uncertain whether available auxiliary sufficient operate stable H-mode. has been...
New experiments at JET with the ITER like wall show for first time that ITER-relevant low field side resonance harmonic ICRH can be used to control sawteeth have been initially lengthened by fast particles.In contrast previous [J.P. Graves et al, Nature Communs 3, 624 (2012)] high sawtooth undertaken JET, it is found of L-mode plasmas controlled less accurate alignment between layer and inversion radius.This advantage, as well discovery shortened various antenna phasings, including dipole,...
Abstract The Joint European Torus recently carried out an experimental campaign using a plasma consisting of both deuterium (D) and tritium (T). We observed high-frequency mode reflectometer interferometer in D-T heated with low power neutral beam injection, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>P</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">N</mml:mi> mathvariant="normal">B</mml:mi> mathvariant="normal">I</mml:mi> </mml:mrow>...
Abstract In this work, we use reduced and perturbative models to examine the stability of toroidal Alfvén eigenmodes (TAEs) during internal transport barrier (ITB) afterglow in JET experiments designed for observation alpha driven TAEs. We demonstrate that JET-like conditions, it is sufficient an incompressible cold plasma model TAE reproduce experimental adiabatic features such as frequency position. When ion cyclotron resonant heating (ICRH) used destabilize TAEs, core-localised modes are...
We present a study of the power threshold for L–H transitions (PLH) in almost pure helium plasmas, obtained recent experiments at JET with an ITER-like wall (Be and W divertor). The most notable new result is that density which PLH minimum, , considerably higher than deuterium hydrogen plasmas. discuss possible implications ITER its pre-fusion operating phase.
Abstract To design a robust termination scenario for burning ITER plasma is challenge that requires extensive core and divertor modelling. The presented work consists of coupled core/edge/SOL/divertor simulations, performed with the JINTRAC code, studying Q=10 flat-top phase exit 15MA/5.3T DT scenario. modelling utilizes recently implemented option to treat deuterium tritium separately in SOL/divertor enabling consistent treatment whole volume which unique capability JINTRAC. In addition,...
Abstract In this work, the MARS-F/K codes (Liu et al 2000 Phys. Plasmas 7 3681; Liu 2008 15 112503) are utilized to model passive and active control of n = 1 ( is toroidal mode number) resistive wall (RWM) in a spherical tokamak (aspect ratio A 1.66). It found that stabilization RWM gives relatively small increase normalized beta above no-wall limit, relying on plasma flow drift kinetic resonance damping from both thermal energetic particles. Results show with flux-to-voltage scheme, which...
Abstract A novel high-performance computing algorithm, developed in response to the next generation of computational challenges associated with burning plasma regimes ITER-scale tokamak devices, has been tested and is described herein. The Lorentz-orbit code for use stellarators tokamaks ( LOCUST ) designed computationally scalable modelling fast-ion dynamics, presence detailed first wall geometries fine 3D magnetic field structures. It achieves this through multiple levels single...
JET experiments have compared the efficacy of low- and high-field side ion cyclotron resonance heating (ICRH) as an actuator to deliberately minimise sawtooth period. It is found that low-field ICRH with low minority concentration optimal for control two main reasons. Firstly, means any toroidal phasing ( $-90^{\circ }$ , $+90^{\circ or dipole) has a destabilising effect on sawteeth, meaning dipole can be employed, since this preferable due less plasma wall interaction from Resonant...
Abstract Recent JET D–T campaigns opened the possibility of unique isotope studies to investigate L–H transition physics in view reactor plasmas and study origin observed power threshold minimum. In present paper, we characterise transitions low high-density branches NBI-heated plasmas. As discussed has been hypothesised be determined by transport losses plasma ions, i.e. so-called ion heat flux ( Q i ). We first balance analysis evaluate at transition. Due experimental setting being similar...
In the initial stages of ITER operation, ELM mitigation systems need to be commissioned. This requires controlled flat-top operation in type-I ELMy H-mode regimes. Hydrogen or helium plasma discharges are used exclusively these ensure negligible production neutrons from fusion reactions. With expected higher L-H power threshold hydrogen and plasmas compared corresponding D D/T plasmas, it is uncertain whether available auxiliary sufficient operate stable H-mode. has been investigated using...
The dynamics of discrete global modes in a toroidal plasma interacting with an energetic particle distribution is studied, and particular when the system using nonlinear quasilinear descriptions are macroscopically similar. can be described bump-on-tail model two-dimensional phase space particles. A Monte Carlo framework developed for this included decorrelation wave- phase, which used to extrinsic stochastisation wave-particle interactions. From description, version also developed, by...
The JT-60SA device offers unique conditions before ITER for the study of interaction energetic particles with plasma waves. With similar dimensions to JET, e.g., a major radius but slightly more elongated volume, is used as high-power where additional heating power (including 10 MW 500 keV Neutral Beam Injection) up 41 and potential high non-inductive current operation pave path numerous challenges in physics on MHD stability, particular, when considering effects particles. Several...
A Monte-Carlo model for interactions between a single Alfven eigenmode and energetic ions in tokamak is presented. phenomenological decorrelation of the wave-particle phase introduced to mimic by collisions or other waves. Analysis dedicated how strength affects nonlinear interactions. Several phenomena that have been observed some earlier models describing dynamics eigenmodes verified, such as growth saturation wave mode amplitude giving rise localized flattening distribution function, well...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation E. Tholerus, T. Hellsten, Johnson; The effects of phase decorrelation on the dynamics bump-on-tail instability. Physics Plasmas 1 August 2015; 22 (8): 082106. https://doi.org/10.1063/1.4928094 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar...
Coupling of an ICRF antenna to fast magnetosonic waves in a toroidal plasma is studied, considering incomplete damping and passive conducting elements, e.g. limiters, near the antenna. The system characterized by coupling broad spectrum partially overlapping resonant modes, whose frequency widths are due finite damping. Small variations parameters, particular density, can change individual modes significantly. Therefore, statistical analysis required. Currents conductors antenna, which...