A5076706254- Magnetic confinement fusion research
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Nuclear reactor physics and engineering
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Anomaly Detection Techniques and Applications
- Network Security and Intrusion Detection
- Groundwater flow and contamination studies
- Seismology and Earthquake Studies
- Plasma and Flow Control in Aerodynamics
- Advanced Data Storage Technologies
- Nuclear Materials and Properties
- Fault Detection and Control Systems
- earthquake and tectonic studies
- Nuclear Physics and Applications
- Earthquake Detection and Analysis
- Particle accelerators and beam dynamics
United Kingdom Atomic Energy Authority
2020-2024
Culham Science Centre
2020-2024
Culham Centre for Fusion Energy
2020-2024
Abstract The JET hybrid scenario has been developed from low plasma current carbon wall discharges to the record-breaking Deuterium-Tritium plasmas obtained in 2021 with ITER-like Be/W wall. development started pure Deuterium refinement of current, and toroidal magnetic field choices succeeded solving heat load challenges arising 37 MW injected power ITER like environment, keeping radiation edge core controlled, avoiding MHD instabilities reaching high neutron rates. have re-run Tritium...
Abstract In view of the future high power nuclear fusion experiments, early identification disruptions is a mandatory requirement, and presently main goal moving from disruption mitigation to avoidance control. this work, deep-convolutional neural network (CNN) proposed provide detection disruptive events at JET. The CNN ability learn relevant features, avoiding hand-engineered feature extraction, has been exploited extract spatiotemporal information 1D plasma profiles. model trained with...
Reliable disruption prediction (DP) and mitigation systems are considered unavoidable during international thermonuclear experimental reactor (ITER) operations in the view of next fusion reactors such as DEMOnstration Power Plant (DEMO) China Fusion Engineering Test Reactor (CFETR). In last two decades, a great number DP have been developed using data-driven methods. The performance models has improved over years both for more appropriate choice diagnostics input features availability...
The achievement of a steady ELMy H-mode phase with high ion temperature, but without gradual rise in plasma radiation, has been crucial point to establish performance scenarios JET ITER-like-wall plasmas. Indeed, radiation events, due the release Z impurities, such as Nickel and Copper, W sputtered from divertor, can strongly reduce power crossing separatrix slow ELMs dynamics, thus inducing H L transition. In particular, baseline plasmas, because outward neoclassical transport [A.R. Field...
In ITER and next step fusion reactors, the chosen materials for first wall are Beryllium Tungsten because of their good thermodynamic mechanical properties, low level erosion, neutron activation, Tritium retention. However, radiation events due to release such high Z materials, can be responsible plasma cooling, which affect ELM dynamics [A.R. Field et al. 2021 Plasma Phys. Control. Fusion 63 095,013], trigger MHD instabilities [G. Pucella Nucl. 61 046,020], inhibit achievement thermonuclear...
Abstract Unusually high power loads on the beryllium limiter caused by neutral beam re-ionisation, and much cooler divertor target surfaces were observed during recent JET tokamak tritium campaign. As both phenomena are driven scrape-off layer (SOL) physics, SOL features of 72 H-mode discharges their deuterium references have been studied. The majority (70) had exponentially decaying profiles. plasmas to increased separatrix density collisionality compared references. This is associated with...
The Sequence of Physics Events (SPE) that leads the plasma towards a disruption can be different in discharges. An Event, this framework, refers to signature physical phenomenon (e.g. peaked ne profile or bolometric peaking factor), whose duration may vary from few ms several hundreds ms. SPE have direct influence on evolution pulses. Then, it is reasonable assume their identification provide relevant information keep discharges within safe operational space. In work, first, set Event...
Abstract The presented data refer to the Shattered Pellet Injector (SPI) experiments carried out at JET in 2019–2020. This paper is a full journal version of originally as posters TMPDM_2020 and EPS_2021. presents various aspects interaction pellets with plasma associated disruptions. experiment was performed I p = (1.1–3.1) MA plasmas mainly Ne + D 2 pellet composition, but also Ar pellets. Current Quench (CQ) time, τ 80−20 , key characteristic mitigation effectiveness. A high content or...
Abstract As JET is developing and testing operational scenarios for higher fusion performance, an increase in pulse disruptivity being observed. On a deeper analysis, we find that several radiative phenomena play active role determining the outcome of pulse. The analysis enabled by use real-time tomography based on bolometer diagnostic. Even though plasma inverse problem, machine learning to train forward model provides radiation profile directly, single matrix multiplication step. This used...
Abstract Recently, a linear disruption predictor (Vega et al 2020 Nucl. Fusion 60 026001) was installed in the JET real-time network for mitigation purposes. From mathematical point of view, is based on computing centroids disruptive examples and non-disruptive two-dimensional space. This reason calling it centroid method (CM). It uses single signal: mode lock normalized to plasma current. The not thresholds trigger alarms but differences amplitudes between consecutive samples. article...