A5072487240- Magnetic confinement fusion research
- Fusion materials and technologies
- Laser-induced spectroscopy and plasma
- Plasma Diagnostics and Applications
- Atomic and Molecular Physics
- Particle accelerators and beam dynamics
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Nuclear reactor physics and engineering
- Laser-Matter Interactions and Applications
- Laser Material Processing Techniques
- Nuclear Physics and Applications
- Laser-Plasma Interactions and Diagnostics
- Model Reduction and Neural Networks
- Gas Dynamics and Kinetic Theory
- Mass Spectrometry Techniques and Applications
- Nuclear Materials and Properties
- X-ray Spectroscopy and Fluorescence Analysis
- Ion-surface interactions and analysis
- Plasma Applications and Diagnostics
- Diamond and Carbon-based Materials Research
Culham Science Centre
2022-2024
United Kingdom Atomic Energy Authority
2022-2024
Culham Centre for Fusion Energy
2023-2024
University College Dublin
2017-2020
Czech Technical University in Prague
2017
Abstract The quasi-continuous exhaust (QCE) regime is a that naturally type-I ELM-free. It combines the high density at plasma edge needed for power with normalised energy confinement typical H-mode operation. In QCE large-scale ELMs are avoided and high-frequent, low-amplitude filaments present leading to name-giving transport of particles energy.
This contribution reports first time was successfully achieved in JET metal wall. More so, it demonstrated recent deuterium-tritium...
Abstract In JET deuterium-tritium (D-T) plasmas, the fusion power is produced through thermonuclear reactions and between thermal ions fast particles generated by neutral beam injection (NBI) heating or accelerated electromagnetic wave in ion cyclotron range of frequencies (ICRFs). To complement experiments with 50/50 D/T mixtures maximizing reactivity, a scenario dominant non-thermal reactivity has been developed successfully demonstrated during second campaign DTE2, as it was predicted to...
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 The work describes the pedestal structure, transport and stability in an effective mass ( A eff ) scan from pure deuterium to tritium plasmas using a type I ELMy H-mode dataset which key parameters that affect behaviour (normalized pressure, ratio of separatrix density density, ion Larmor radius, collisionality rotation) are kept as constant possible. Experimental results show significant increase at top with increasing , modest reduction temperature pressure. variations heights...
Abstract In the paper we present an overview of interpretive modelling a database JET-ILW 2021 D-T discharges using TRANSP code. The main aim is to assess our capability computationally reproducing fusion performance various plasma scenarios different external heating and mixtures, understand driving mechanisms. We find that simulations confirm general power-law relationship between increasing power output, which supported by absolutely calibrated neutron yield measurements. A comparison...
Abstract The paper reports the first demonstration of in situ laser-induced desorption — quadrupole mass spectrometry (LID-QMS) application on a large scale fusion device performed summer 2023. LID-QMS allows direct measurements fuel inventory plasma facing components without retrieving them from device. diagnostic desorbs retained gases by heating 3 mm diameter spot wall using 1 ms long laser pulse and detects QMS. Thus, it can measure gas content at any position accessible to laser....
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 The pre-thermal quench (pre-TQ) dynamics of a pure deuterium ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi mathvariant="normal">D</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:math> ) shattered pellet injection (SPI) into <mml:mn>3</mml:mn> <mml:mstyle scriptlevel="0"/> <mml:mi>MA</mml:mi> / <mml:mn>7</mml:mn> <mml:mi>MJ</mml:mi> JET H-mode plasma is studied via 3D non-linear MHD modelling with the JOREK code....
Abstract JET returned to deuterium-tritium operations in 2023 (DTE3 campaign), approximately two years after DTE2. DTE3 was designed as an extension of JET's 2022-2023 deuterium campaigns, which focused on developing scenarios for ITER and DEMO, integrating in-depth physics understanding control schemes. These were evaluated with mixed D-T fuel, using the only remaining tritium-capable tokamak until its closure 2023. A core-edge-SOL integrated H-mode scenario developed tested D-T, showing...
Abstract The required heating power, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>P</mml:mi> <mml:mi>LH</mml:mi> </mml:mrow> </mml:msub> </mml:math> , to access the high confinement regime (H-mode) in tritium containing plasmas is investigated JET with ITER-like wall at a toroidal magnetic field of <mml:mi>B</mml:mi> <mml:mi>t</mml:mi> <mml:mo>=</mml:mo> <mml:mn>1.8</mml:mn> T and plasma current <mml:mi>I</mml:mi>...
Abstract Divertor power load is a major challenge towards burning plasma in next-step tokamak. Here, the first results of divertor characterisation tritium plasmas type-I ELMy H-mode, obtained JET deuterium-tritium campaign (DTE2) performed 2021, are presented. It demonstrated that both, transient loads due to ELMs as well fall-off length, do not exhibit an explicit ion mass dependence, with remarkably similar values and deuterium references. This gives improved credence published scaling...
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...
Soft x-ray emission spectra of dysprosium, erbium and thulium ions created in laser-produced plasmas were recorded with a flat-field grazing-incidence spectrometer the 2.5–8 nm spectral range. The produced using an Nd:YAG laser 7 ns pulse duration at various power densities. experimental interpreted aid Cowan suite atomic structure codes flexible code. At wavelengths above 5.5 are dominated by overlapping n = 4 − unresolved transition arrays from adjacent ion stages. Below 6 nm, 5...
Thomson scattered light is polarized in the same orientation as incident laser beam at low electron temperatures (Te). At high Te, part of spectrum begins to become randomly due relativistic reasons. First measurements depolarized scattering were obtained from Joint European Torus (JET) pulses 2016. This paper builds upon these initial with data during 2021. These new improve first results, particular, by obtaining spectral spectrum. The recent JET campaign was well suited long and hot...
Abstract A statistical analysis is carried out of the similarity profiles plasma parameters: electron temperature T e , density n and pressure P at stage quasi-stationary current (the so called flat-top stage) about 9000 discharges in JET tokamak, among from #84458 to #99419 that covers almost entire database successful ITER-like wall machine. For all these parameters, existence universal shown as functions normalized minor radius column ρ . The discharge (DUPs) are obtained by dividing...
The present paper is dedicated to the study of discrepancies encountered in electron temperature (Te) measurements carried out with cyclotron emission (ECE) and Thomson scattering (TS) diagnostics core JET tokamak. A large database discharges has been collected, including high-performance scenarios performed deuterium only deuterium–tritium mixtures. Discrepancies have found between Te taken an X-mode ECE interferometer (TECE) a LIDAR TS system (TLID) for Te&gt;5 keV. Depending on plasma...
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...
This work presents a system upgrade of the High Resolution Thomson Scattering (HRTS) diagnostic [Pasqualotto et al., Rev. Sci. Instrum. 75, 3891-3893 (2004)] on JET that allows it to measure low temperature (1-500 eV) plasma pre- and post-Thermal quench (TQ), which would help us further understand Shattered Pellet Injection (SPI) physics. The was done by connecting optic fibers from original HRTS four spectrometers specialized in measuring plasmas. upgraded for measurement at up 12 spatial...
For high-temperature JET and TFTR discharges, electron cyclotron emission (ECE) measurements of central temperature were systematically found to be up 20% higher than those taken with Thomson scattering. In recent high-performance T e measurements, performed LIDAR scattering the X-mode ECE interferometer, have been studied in a large database, including deuterium (DD), deuterium-tritium plasmas (DT). Discrepancies between observed outside experimental uncertainties. at high , or lower LIDAR,...
The soft x-ray emission spectra of femtosecond-laser-produced plasmas from 2nd row transition elements yttrium (Z = 39) to palladium 46), with the exception technetium 43), were measured in 1–5 nm region. Plasmas produced by shining pulses a titanium–sapphire laser 65 fs pulse duration and an energy per 4.5 mJ focused intensity 3 × 1015 W cm−2 onto bulk targets. While molybdenum 42) contain only unresolved arrays (UTA) already observed nanosecond picosecond laser-target interactions...
Abstract The effects of shape and thickness a tin surface layer the energy 170 ps neodymium:yttrium-aluminum-garnet laser pulse on conversion efficiency (CE) into extreme ultraviolet emission in 13.5 nm region is investigated. Whereas CE up to 1.16% 2% reflection band multilayer Mo/Si optics was measured for bulk Sn target at 25 mJ, significant enhancement 1.49% demonstrated 200-nm-thick microstructured porous alumina substrate.