A5059443777- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Nuclear reactor physics and engineering
- Solar and Space Plasma Dynamics
- Per- and polyfluoroalkyl substances research
- Quantum, superfluid, helium dynamics
- Atomic and Subatomic Physics Research
- Laser-induced spectroscopy and plasma
- Advanced MRI Techniques and Applications
- Advanced Aircraft Design and Technologies
- Earthquake and Tsunami Effects
- Advanced Frequency and Time Standards
- Advanced NMR Techniques and Applications
- Effects and risks of endocrine disrupting chemicals
- Gas Dynamics and Kinetic Theory
- Toxic Organic Pollutants Impact
- Nuclear Materials and Properties
- Physics of Superconductivity and Magnetism
- Calibration and Measurement Techniques
Culham Centre for Fusion Energy
2012-2025
Culham Science Centre
2015-2024
United Kingdom Atomic Energy Authority
2019-2024
California Environmental Protection Agency
2022
National Centre for Nuclear Research
2021
University of Liverpool
2011-2013
CEA Cadarache
2013
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2011-2013
Rutherford Appleton Laboratory
2009
Divertor detachment is explored on the TCV tokamak in alternative magnetic geometries. Starting from typical single-null shapes, poloidal flux expansion at outer strikepoint varied by a factor of 10 to investigate X-divertor characteristics, and total 70 study properties super-X divertor. The effect an additional X-point near target investigated divertors. Detachment studied these plasmas during Ohmic density ramps with ion B drift away primary X-point. threshold, depth detachment, stability...
Abstract The tokamak à configuration variable (TCV) continues to leverage its unique shaping capabilities, flexible heating systems and modern control system address critical issues in preparation for ITER a fusion power plant. For the 2019–20 campaign configurational flexibility has been enhanced with installation of removable divertor gas baffles, diagnostic capabilities an extensive set upgrades new dual frequency gyrotrons. baffles reduce coupling between main chamber allow detailed...
The TCV tokamak is augmenting its unique historical capabilities (strong shaping, strong electron heating) with ion heating, additional heating compatible high densities, and variable divertor geometry, in a multifaceted upgrade program designed to broaden operational range without sacrificing fundamental flexibility. rooted three-pronged approach aimed at ITER support, explorations towards DEMO, research. A 1 MW, tangential neutral beam injector (NBI) was recently installed promptly...
Abstract The research program of the TCV tokamak ranges from conventional to advanced-tokamak scenarios and alternative divertor configurations, exploratory plasmas driven by theoretical insight, exploiting device’s unique shaping capabilities. Disruption avoidance real-time locked mode prevention or unlocking with electron-cyclotron resonance heating (ECRH) was thoroughly documented, using magnetic radiation triggers. Runaway generation high- Z noble-gas injection runaway dissipation...
Major developments on the Mega Amp Spherical Tokamak (MAST) have enabled important advances in support of ITER and physics basis a spherical tokamak (ST) based component test facility (CTF), as well providing new insight into underlying physics. For example, L–H transition studies benefit from high spatial temporal resolution measurements pedestal profile evolution (temperature, density radial electric field) stability edge current has been inferred motional Stark effect measurements. The...
SOLPS simulations of MAST-U have been carried out to identify in more detail the physics and operational properties novel divertor configurations such as Super-x (SXD), particular detachment. A well diagnosed L-mode discharge from MAST has utilised determine transport coefficients representative for plasmas. Simulations show that under same core plasma conditions, SXD is strongly detached whilst conventional (CD) not (1 eV versus 20 at plate). The detachment higher power losses (1.6×)...
This paper investigates the power loads at inner and outer divertor targets of attached, Ohmic L-mode, deuterium plasmas in TCV tokamak, various experimental situations using an Infrared thermography system. The study comprises variations leg length target flux expansion, plasma current a reversal magnetic field direction. direct impact geometry on scrape-off layer (SOL) transport—parameterised by SOL fall-off , spreading factor Su in-out asymmetry—is reported for constant core properties....
Divertor detachment in the TCV tokamak has been investigated through experiments and modelling. Density ramp were carried out ohmic heated L-mode pulses with ion ∇B drift directed away from primary X-point, similar to previous studies [1]. Before roll-over current outer strike point, C III Dα emission leg recede slowly point toward at a rate of ∼2.0 × 10−19 m/m−3 along magnetic field as electron temperature reduces increasing density. Around onset detachment, upstream density profile target...
The mega amp spherical tokamak (MAST) was a low aspect ratio device (R/a = 0.85/0.65 ~ 1.3) with similar poloidal cross-section to other medium-size tokamaks. physics programme concentrates on addressing key issues for the operation of ITER, design DEMO and future tokamaks by utilising high resolution diagnostic measurements closely coupled theory modelling significantly advance our understanding. An empirical scaling energy confinement time that favours higher power, lower collisionality...
Partial detachment is the desired regime for baseline burning plasma scenario in ITER and next-step devices, as it allows to dissipate majority of energy carried by charged particles through scrape-off-layer (SOL) thus avoids localised heat flux deposition divertor region.The COMPASS tokamak equipped with an open has a relatively short connection length, both factors being unfavourable access detachment.As such, only approach naturally detached operation at very high lineaveraged densities...
Abstract This contribution aims to improve existing scalings of the L-mode power decay length <?CDATA ${\lambda_{q}^{{\rm omp}}}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msubsup> <mml:mi>λ</mml:mi> <mml:mi>q</mml:mi> </mml:mrow> <mml:mi mathvariant="normal">o</mml:mi> mathvariant="normal">m</mml:mi> mathvariant="normal">p</mml:mi> </mml:msubsup> </mml:math> , especially for plasma configurations with strike points at ITER-relevant...
Knowing the ion temperature in scrape-off layer (SOL) of tokamaks is great importance for understanding heat flux to plasma facing components. Few measurements are available SOL temperatures compared with electron due relative complexity measurement. Two retarding field energy analysers (RFEAs) have been used mega amp spherical tokamak (MAST) measure at both midplane and divertor ohmic L-mode plasmas a range densities. Midplane Ti was found be higher than Te by factor about 2 or greater....
A deep understanding of plasma transport at the edge magnetically confined fusion plasmas is needed for handling and control heat loads on machine first wall. Experimental observations collected a number tokamaks over last three decades taught us that flux profiles divertor targets X-point configurations can be parametrized by using two scale lengths scrape-off layer (SOL) transport, separately characterizing main SOL () (Sq). In this work we challenge current interpretation these as well...
The STORM module of BOUT++ (Easy et al 2014 Phys. Plasmas 21 122515) is generalized to simulate plasma turbulence at the periphery tokamak devices in diverted configurations and it used carry out three-dimensional nonlinear flux-driven simulations double null configuration with realistic experimental parameters an L-mode discharge Mega Ampere Spherical Tokamak. reliability modeling scrape-off layer (SOL) dynamics assessed by comparing numerical results measurements from a reciprocating...
Abstract Spherical tokamaks are key to the successful design of operating scenarios future fusion reactors in areas divertor physics, neutral beam current drive and fast ion physics. MAST Upgrade, which has successfully concluded its first experimental campaign, was specifically designed address role radial gradient distribution driving excitation magneto-hydrodynamic (MHD) instabilities, such as toroidal Alfvén eigenmodes, fish-bones long-lived mode, thanks two tangential injection systems,...
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...
Retarding field energy analysers (RFEAs) have been used to compare the ion temperature (Ti) of large plasma filaments with background (composed small scale filaments) at midplane and divertor target in L mode discharges Mega Amp spherical tokamak (MAST). At low densities, divertor, distances from 2 4 cm separatrix ions was found be 3 times larger than plasma. midplane, electron for both around 7 smaller had a flat profile across scrape off layer (SOL). higher filament temperatures were...
A detailed description of the Langmuir probe system on Mega Ampere Spherical Tokamak Upgrade is presented. The features 850 tile-embedded probes and 40 bespoke electronic modules that each have capability to drive acquire data from up 16 in a time-multiplexed manner. provides spatiotemporal-resolved measurements (1 cm ∼1 ms, respectively) divertor region ion saturation current, electron temperature, floating potential. standard interpretation current-voltage (IV) characteristics apply...
Abstract Recent results from MAST Upgrade are presented, emphasising understanding the capabilities of this new device and deepening key physics issues for operation ITER design future fusion power plants. The impact MHD instabilities on fast ion confinement have been studied, including first observation losses correlated with Compressional Global Alfvén Eigenmodes. High-performance plasma scenarios developed by tailoring early current ramp phase to avoid internal reconnection events,...
New diagnostic, modelling and plant capability on the Mega Ampère Spherical Tokamak (MAST) have delivered important results in key areas for ITER/DEMO upcoming MAST Upgrade, a step towards future ST devices path to fusion currently under procurement. Micro-stability analysis of pedestal highlights potential roles micro-tearing modes kinetic ballooning formation. Mitigation edge localized (ELM) using resonant magnetic perturbation has been demonstrated toroidal mode numbers n = 3, 4, 6 with...
The ball pen probe (BPP) technique is used successfully to make profile measurements of plasma potential, electron temperature and radial electric field on the Mega Amp Spherical Tokamak (MAST). potential measured by BPP shown significantly differ from floating both in polarity shape. By combining can be measured, which compared with Thomson scattering (TS) diagnostic. Excellent agreement between two diagnostics obtained when secondary emission accounted for potential. From an estimate...
New measurements of ion energies and currents in type I mitigated ELMs have been carried out the ASDEX Upgrade far scrape-off layer using a retarding field analyser (RFA). The temperature averaged over an ELM, T i ELM measured 35–60 mm outside separatrix (i.e. 15–25 front outboard limiter) is range 20–200 eV, which 5–50% at pedestal top. decreases with distance e-folding length ∼10 SOL for particular set conditions, increases energy W . Lowest during ELMs. Likewise, ELM-averaged current ,...