A5060386422- Magnetic confinement fusion research
- Fusion materials and technologies
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Ionosphere and magnetosphere dynamics
- Nuclear reactor physics and engineering
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Nuclear Physics and Applications
- Health, Environment, Cognitive Aging
- Optical measurement and interference techniques
- Particle Accelerators and Free-Electron Lasers
- Metallurgical Processes and Thermodynamics
- Delphi Technique in Research
- Infrared Target Detection Methodologies
- Laser-induced spectroscopy and plasma
- Single-cell and spatial transcriptomics
- Laser-Matter Interactions and Applications
- Advanced Frequency and Time Standards
- Radiation Effects in Electronics
- Cell Image Analysis Techniques
- Fault Detection and Control Systems
- Calibration and Measurement Techniques
- Astronomical Observations and Instrumentation
- Medical Imaging Techniques and Applications
Oak Ridge National Laboratory
2019-2024
Culham Centre for Fusion Energy
2016-2023
Culham Science Centre
2016-2023
United Kingdom Atomic Energy Authority
2019-2023
Massachusetts Institute of Technology
2019-2021
Royal Military Academy
2020
Durham University
2016-2019
Abstract A series of experiments have been executed at JET to assess the efficacy newly installed shattered pellet injection (SPI) system in mitigating effects disruptions. Issues, important for ITER disruption mitigation system, such as thermal load mitigation, avoidance runaway electron (RE) formation, radiation asymmetries during quench electromagnetic control and RE energy dissipation addressed over a large parameter range. The efficiency has examined various SPI strategies. paper...
Abstract Precise values for radiated energy in tokamak disruption experiments are needed to validate mitigation techniques burning plasma tokamaks like ITER and SPARC. Control room analysis of power ( P rad ) on JET assumes axisymmetry, since fitting 3D radiation structures with limited bolometry coverage is an under-determined problem. In mitigated disruptions, toroidally asymmetric 3D, due fast-growing MHD modes localized impurity sources. To address this problem, Emis3D adopts a physics...
Abstract The integration of good core and edge/pedestal confinement with strong dissipation heat particles in the divertors is a significant challenge for development fusion energy. Alternative divertor configurations offer potential advantages by broadening operational space where device can operate detached acceptable power exhaust. First results from MAST Upgrade are presented high mode experiments outer Super-X configuration, showing that naturally detach when formed no discernible...
Summary: The Imaging and Molecular Annotation of Xenografts Tumors Cancer Grand Challenges team was set up with the objective developing “next generation” pathology cancer research by using a combination single-cell spatial omics tools to produce 3D molecularly annotated maps tumors. Its activities overlapped, in some cases catalyzed, revolution biology that saw new technologies being deployed investigate roles tumor heterogeneity micro-environment. See related article Stratton et al., p. 22...
<p>IMAXT Consortium Author List</p>
<div>Summary:<p>The Imaging and Molecular Annotation of Xenografts Tumors Cancer Grand Challenges team was set up with the objective developing “next generation” pathology cancer research by using a combination single-cell spatial omics tools to produce 3D molecularly annotated maps tumors. Its activities overlapped, in some cases catalyzed, revolution biology that saw new technologies being deployed investigate roles tumor heterogeneity micro-environment.</p><p><a...
<p>IMAXT Consortium Author List</p>
Abstract Spherical tokamaks (STs) present unique challenges and opportunities in the area of particle power exhaust, intensified due to their more compact sizes.&#xD;Substantial efforts are underway STs determine limits dissipative operational regimes advanced divertor solutions, including at MAST-U which provides access Super-X configuration.&#xD;Power balance, upper/lower asymmetries have been studied using SOLPS-ITER simulations divertor. &#xD;A set with experimentally...
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...
A prototype infrared video bolometer (IRVB) was successfully deployed in the Mega Ampere Spherical Tokamak Upgrade (MAST or MAST-U), first deployment of such a diagnostic spherical tokamak. The IRVB designed to study radiation around lower x-point, another tokamaks, and has potential estimate emissivity profiles with spatial resolution beyond what is achievable resistive bolometry. system fully characterized prior installation on MAST-U, results are summarized here. After installation, it...
A new system of probes was recently installed in the divertor tokamak COMPASS order to investigate ELM energy density with high spatial and temporal resolution. The consists two arrays rooftop-shaped Langmuir (LPs) used measure floating potential or ion saturation current one array Ball-pen (BPPs) plasma a resolution ~3.5 mm. combination BPPs LPs yields electron temperature microsecond We report on design probe first results profile measurements ELMy H-mode L-mode. also present comparative...
Abstract Disruption mitigation remains a critical, unresolved challenge for ITER. To aid in addressing this challenge, shattered pellet injection (SPI) system was installed on JET and experiments conducted at range of thermal energy fractions stored energies excess 7 MJ. The primary goals these were to investigate the efficacy SPI ability plasma assimilate multiple pellets. Single injections produced saturation total radiated ( W rad ) with increasing injected neon content, suggesting...
A suite of multi-channel resistive bolometers has been implemented to measure the total radiation from Mega Amp Spherical Tokamak Upgrade plasmas, with cameras covering core plasma and lower divertor chamber. Data are digitized processed using novel field-programmable gate array-based electronics, offering improved compactness new operational capabilities. synthetic diagnostic developed explore quality 2D reconstructions available system quantify uncertainty on quantities such as radiated...
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 Real-time magnetic control has been developed to deliver precise of multiple plasma shape parameters for advanced divertor configurations, including double-null, Super-X, X-point target and X-divertor the first time on MAST Upgrade (MAST-U) spherical tokamak. Successful real-time equilibrium different variables accomplished in 2022–2023 MAST-U experimental campaign configurations. Application boundary reconstruction algorithm, LEMUR, is described compared with off-line diagnostic...
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...
Abstract A tomographic method for reconstructing the axially symmetric D α emission profile in ITER scrape-off layer and divertor from intensity measurements fields of view (FoV) Vis/IR TV Divertor Impurity Monitor diagnostics is under development. The takes into account strong background signal due to stray light produced by reflections metal wall vacuum chamber. allows filter out signals measured main accuracy this tested within framework a synthetic diagnostic, which uses Raysect Cherab...
Laser-wakefield accelerators (LWFAs) driven by widely available 100s TW-class near-infrared laser systems have been shown to produce GeV-level electron beams with 10s-100s pC charge in centimetre-scale plasma. As the strength of ponderomotive force is proportional square wavelength, more efficient LWFAs could be realised using longer wavelength lasers. Here we present a numerical study showing that [Formula: see text], sub-picosecond CO2 lasers peak powers 100-800 TW can high-charge beams,...
Abstract A new method for estimating the global erosion of beryllium (Be) in ITER is proposed. The uses raytracing-aided tomography to reconstruct three-dimensional (3D) profile visible-light emissivity boundary plasma from images captured with filtered cameras VIS/IR wide angle viewing system, H-alpha (and Visible) Spectroscopy diagnostics and signals collected Divertor Impurity Monitor. light reflected into detectors metallic plasma-facing components (PFCs) out process. reconstructed Be...
<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...
Plasma detachment involves interactions of the plasma with impurities and neutral particles, leading to significant losses power, momentum, particles. Accurate mapping emissivity in divertor X-point region is essential for assessing relationship between particle flux radiative detachment. The recently validated InfraRed Video Bolometer (IRVB) diagnostic, MAST-U enables this higher spatial resolution than more established methods like resistive bolometers. In previous preliminary work,...
A new resistive bolometer system has been developed for MAST-Upgrade. It will measure radiated power in the Super-X divertor, with millisecond time resolution, along 16 vertical and horizontal lines of sight. The uses a Xilinx Zynq-7000 series Field-Programmable Gate Array (FPGA) D-TACQ ACQ2106 carrier to perform real data acquisition signal processing. FPGA enables AC-synchronous detection using high performance digital filtering achieve signal-to-noise ratio be able output processed...
This paper presents techniques for evaluating the radiated power in JET disruptions. Disrupting plasmas are shown to have non-axisymmetric radiation profiles, motivating re-evaluation of standard calculating total at using bolometry. Four single-channel bolometers different toroidal locations exploited quantify asymmetry. Toroidal peaking factors integrated over entire disruption up 1.5 been observed when varying quantity neon pellets used disruptions mitigated by shattered pellet injection....
High bandwidth, high spatial resolution measurements of electron temperature, density, and plasma potential are valuable for resolving turbulence in the boundary tokamaks. While conventional Langmuir probes can provide such measurements, either their temporal or is limited: former by sweep rate necessary obtaining I-V characteristics latter need to use multiple electrodes, as case triple double probe configurations. The Mirror Probe (MLP) bias technique overcomes these limitations rapidly...
In this paper we report on the development and demonstration of density feedback control for MAST-U. Sinusoidal perturbations are used to measure frequency response from a deuterium gas valve (actuator) line-integrated core electron measured by interferometer (sensor). range relevant design, only two system-identification experiments were needed regress first-order dynamic model. This control-oriented model informs offline design proportional integral controller with established loop-shaping...