A5037579108- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Nuclear Physics and Applications
- Solar and Space Plasma Dynamics
- Restraint-Related Deaths
- Nuclear reactor physics and engineering
- Plasma Diagnostics and Applications
Tokamak Energy (United Kingdom)
2023-2025
University of York
2020-2023
University of California, Los Angeles
2021
Ioffe Institute
2017-2020
The Globus-M spherical tokamak has demonstrated practically all of the project objectives during 15-year period operation. main factor limiting further progress in plasma performance is a relatively low toroidal magnetic field. maximum field achieved on was 0.4 T with exception limited number shots 0.55 T, which led to damage coil 2002. increase up 1.0 together current 0.5 MA will result significant enhancement operating parameters upgraded Globus-M2 machine. experimental program be focused...
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...
A technique, volumetric power optimization, is presented for enhancing the output of magnetic confinement fusion devices. Applied to a tokamak, this approach involves shifting burning plasma region larger volume while introducing minimal perturbations boundary shape. This edge perturbation—squareness—is analogous pinching and stretching boundary. Stability calculations confirm that alteration compatible with maintaining stability. optimization method optimizing could improve performance...
In this paper, the turbulent transport properties of ST40 hot ion plasmas are examined and fully predictive time evolving modelling a plasma pulse was performed. Understanding on spherical tokamaks (STs) is challenging due to their unique geometry characteristics. typically unstable scale Trapped Electron Modes (TEMs) Ubiquitous (UMs), driven from kinetic response trapped particles passing ions, electron Temperature Gradient (ETGs) at edge plasma. A comparison between linear modes...
Abstract In the final Globus-M experimental campaign B tor and I p were raised by 25% up to 0.5 T 250 kA, respectively, expanding available range of parameters. these experiments an overall improvement in plasma performance was observed, total stored energy neutron rate increased significantly. The confinement time dependence on n e close linear. L-H transition threshold 5–10 times higher than predicted scaling. Despite small plasma-wall distance, level radiation losses main volume...
Abstract Like most magnetic confined fusion experiments, the ST40 tokamak started off with a small subset of diagnostics and gradually increased diagnostic set to include more complex comprehensive systems. To make each operational phase, forward models various are used developed aid design, provide consistency-checks during commissioning, test analysis methods, build workflows constrain high-level parameters inform interpretation, theory modelling. For new workflows, minimum-viable-products...
Following successful campaigns on the compact high field spherical tokamak ST40, resistive gold foil bolometers have now been installed to measure radiated power profile. Positioned midplane, two bolometer cameras offer perspectives of horizontal and vertical planes, while third camera, situated above provides a view top divertor plates, including X-point strike points. These use commercial off-the-shelf data acquisition platform with modules specifically designed for in Wheatstone bridge...
The paper presents the latest results and summarizes study of ion heat transport in Globus-M spherical tokamak regimes with neutral beam injection. Ion was investigated discharges various toroidal magnetic fields plasma currents. Measurements temperature were carried out using charge-exchange recombination spectroscopy a particle analyzer. Plasma simulations code ASTRA have shown that is predominantly neoclassical even for low collisionality range. local analysis indicates core stable to...
Recent research at three small tokamaks with different parameters located the Ioffe Institute—the spherical tokamak Globus-M, large aspect ratio FT-2 and compact TUMAN-3M—are reviewed. This overview covers energy confinement (Globus-M FT-2), L–H transition (TUMAN-3M Alfvén waves TUMAN-3M), ion cyclotron emission (TUMAN-3M), major plasma discharge disruption (Globus-M) scrape-off layer studies. A full-f global gyrokinetic modeling benchmark using synthetic diagnostics in is described....
The Globus-M2 spherical tokamak is the considerably upgraded Globus-M facility. Its technical parameters were increased as much possible to achieve promising range of physical (sub-fusion temperatures and collisionality less than unity). These will be achieved in a compact magnetic configuration similar that tokamak, plasma current toroidal field amounting 0.5 MA 1 T, respectively. demand increase resulted need for complete redesign electromagnetic system because equilibrium requirements...
A diagnostic system for plasma radiated power tomography on Globus-M was upgraded with a new linear array based silicon photodiodes. The hardware of the 256-channel tangential matrix and 24-channel is described. algorithm 2D tomographic reconstruction emissivity presented. It uses Tikhonov regularization method anisotropic diffusion functional as side constraint. Simulated profiles were used to test assess capabilities developed algorithm. Data analysis carried out in ohmic neutral beam...
The properties of the edge ion-scale turbulence are studied using beam emission spectroscopy (BES) diagnostic on MAST. Evidence formation large-scale high-amplitude coherent structures, filamentary density blobs and holes, 2–4 cm inside plasma separatrix is presented. Measurements radial velocity skewness fluctuations indicate that holes propagate radially inwards, with profile peaking at 7–10 separatrix. Poloidal velocities measured cross-correlation time delay estimation (CCTDE) found to...
Deep plasma fueling by the injection of high-speed high-density hydrogen jet has been observed on Globus-M unmagnetized a gun led to twofold increase core density. Presented here are results measurement velocities during movement in tokamak plasma. It is demonstrated that deceleration times and helium jets accordance with predictions penetration models based consideration Alfvén conductivity inhomogeneity curvature magnetic field. confirmed main mechanism governing depth for considered...
Analysis of stability the peeling-ballooning modes in edge plasma Globus-M tokamak is presented. Studies were performed using ideal 3D MHD code written BOUT++ framework. The localized which are frequently observed could be described theory. It was found that parameters range for modes. instability with a toroidal number n = 12 and typical distances between filaments approximately ∼12 cm to most unstable. This statement agrees Doppler backscattering measurements. also considered whether...
A new burn control scheme for tokamaks is described where the total fusion power controlled by adjusting plasma volume fraction that packed into dense regions. In an example spherical tokamak burning plasma, modifying edge squareness doubled at almost constant and density. Therefore, increased could be extremely beneficial to a reactor desirable load balancing. Experiments have observed impact of on modified core volume, highlighting practical relevance this approach.
As part of its roadmap to developing commercial fusion plants, Tokamak Energy Ltd. operates the high field spherical tokamak ST40. Studies on this device will help expand physics basis by characterizing confinement and triple product. In support this, bolometers broadband x-ray sensitive diodes can provide information key energy loss mechanisms plasma. These include core magnetohydrodynamic activity that deteriorates confinement, such as sawtooth crashes be used characterize relaxations in...
This paper presents the measurement results of radiated power Prad and effective ion charge Zeff in a toroidal magnetic field up to 0.7 T plasma current 300 kA for wide range electron density, which were first obtained on Globus-M2 tokamak. An analysis demonstrated that content radiation losses relative input decreased tokamak compared Globus-M tokamak, measured profiles had strong dip central region. In addition, decrease with increasing density was observed.
Embedding diagnostics in future pilot plants will be a challenging task, because of space- and irradiation-related concerns. Relying on high-fidelity synthetic would then valuable. The 3D Monte-Carlo ray-tracing code CHERAB allows the development numerous spectroscopic diagnostics. Focus present work is introduction new models. forward modelling Dα camera ST40, privately funded, high-field spherical tokamak, owned operated by Tokamak Energy Ltd, comparison against experimental data chosen as...
The properties of the edge ion-scale turbulence are studied using beam emission spectroscopy (BES) diagnostic on MAST. Evidence formation large-scale high-amplitude coherent structures, filamentary density blobs and holes, 2$-$4 cm inside plasma separatrix is presented. Measurements radial velocity skewness fluctuations indicate that holes propagate radially inwards, with profile peaking at 7$-$10 separatrix. Poloidal velocities measured cross-correlation time delay estimation (CCTDE) found...