A. Chomiczewska
A5022471268- Magnetic confinement fusion research
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Plasma Diagnostics and Applications
- Nuclear reactor physics and engineering
- Mass Spectrometry Techniques and Applications
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Viral Infections and Vectors
- Laser-induced spectroscopy and plasma
Institute of Plasma Physics and Laser Microfusion
2020-2024
Abstract WEST is an MA class superconducting, actively cooled, full tungsten (W) tokamak, designed to operate in long pulses up 1000 s. In support of ITER operation and DEMO conceptual activities, key missions are: (i) qualification high heat flux plasma-facing components integrating both technological physics aspects relevant particle exhaust conditions, particularly for the monoblocks foreseen divertor; (ii) integrated steady-state at confinement, with a focus on power issues. During phase...
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...
This paper summarizes the physical principles behind novel three-ion scenarios using radio frequency waves in ion cyclotron range of frequencies (ICRF). We discuss how to transform mode conversion electron heating into a new flexible ICRF technique for and fast-ion generation multi-ion species plasmas. The theoretical section provides practical recipes selecting plasma composition realize scenarios, including two equivalent possibilities choice resonant absorbers that have been identified....
Abstract We present recent highlights from the most operation phases of Wendelstein 7-X, advanced stellarator in world. Stable detachment with good particle exhaust, low impurity content, and energy confinement times exceeding 100 ms, have been maintained for tens seconds. Pellet fueling allows plasma reduced ion-temperature-gradient turbulence, during such phases, overall is so (energy often 200 ms) that attained density temperature profiles would not possible less optimized devices, since...
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 As part the DTE2 campaign in JET tokamak, we conducted a parameter scan T and D-T complementing existing pulses H D. For different main ion masses, type-I ELMy H-modes at fixed plasma current magnetic field can have pedestal pressure varying by factor of 4 total changing from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>β</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">N</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo>...
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 dimensionless isotope mass scaling experiment between pure Deuterium and Tritium plasmas with matched <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mi>ρ</mml:mi> <mml:mo>∗</mml:mo> </mml:msup> </mml:math> , <mml:mi>ν</mml:mi> β n q <mml:msub> <mml:mi>T</mml:mi> <mml:mi>e</mml:mi> </mml:msub> <mml:mrow> <mml:mo>/</mml:mo> </mml:mrow> <mml:mi>i</mml:mi> has been achieved in JET L-mode dominant electron heating (NBI+ohmic) conditions....
Beam-target reactions are responsible for a substantial fraction of the fusion power generated in D-T plasmas JET-ILW (Be/W-wall), with ion temperatures 10-12keV and large neutral-beam injection (NBI) power.It is known that injecting D beam ions energies ~100-150keV T-rich has larger potential beam-target than 50:50 D:T plasmas, but such scenario was never developed past experiments performed JET-C (Carbon-wall) TFTR 90's.On top intrinsic advantages using beams neutron production,...
Abstract The two best performing pulses of the so called ITER-Baseline scenario ( I p = 3.5 MA and P in ≈ 35 MW) JET-ITER like wall, one deuterium (D) other deuterium–tritium (D–T) plasma are examined compared this study. Generally, D–T Baseline exhibit an electron density level higher than D energy is comparable by up to 20%, reaching about 12 MJ pulse studied here. In contrast with pulses, often characterised increase time radiated power mantle region (0.70 < ρ 0.95), which may lead...
Abstract The experimental and theoretical analysis were focused on experiments conducted to assess the effect of plasma isotopes, protium (H), deuterium (D), tritium (T) ion cyclotron resonance heating (ICRH) related wall interactions. Comparison L-mode discharges with N = 1 3 He H minority ICRH scenarios done for different isotopes. For selected pulses, behaviour high-Z, mid-Z low-Z intrinsic impurity radiated power was investigated based data from VUV, visible spectroscopy, bolometry...
Abstract The mission of WEST (tungsten-W Environment in Steady-state Tokamak) is to explore long pulse operation a full tungsten (W) environment for preparing next-step fusion devices (ITER and DEMO) with focus on testing the ITER actively cooled W divertor tokamak conditions. Following successful completion phase 1 (2016-2021), 2 started December 2022 lower made entirely ITER-grade mono-blocks. A boronization prior first plasma attempt allowed smooth startup new divertor. Despite reduced...
Abstract Tokamak à configuration variable (TCV), recently celebrating 30 years of near-continual operation, continues in its missions to advance outstanding key physics and operational scenario issues for ITER the design future power plants such as DEMO. The main machine heating systems changes are first described. Then follow five sections: plasma scenarios. Base-Line (IBL) discharges, triangularity studies together with X3 N2 seeding. Edge localised mode suppression, a high radiation...
Abstract Density peaking has been studied between an ICRH and NBI identity plasma in JET. The comparison shows that 8 MW of heating/fueling increases the density by a factor two, being R / L n = 0.45 for pulse 0.93 one averaged radially over ρ tor 0.4, 0.8. dimensionless profiles q , * υ β T i e ≈ 1 were matched within 5% difference except central part ( < 0.3). curvature pinch (same -profile) thermo-pinch ) discharges is virtually zero. Both gyro-kinetic simulations integrated modelling...
Abstract Self-consistent core-scrape-off layer numerical simulations of an ASDEX-Upgrade discharge where the nitrogen (N) seeding is gradually replaced with krypton (Kr) during plasma current flat-top phase are presented. These performed COREDIV code focusing on prediction impurity evolution (W, Kr, N) matched global parameters: total and core radiation, temperature at target plate W concentration. The results compared experimental measurements for shot #30503 three different time points:...
Abstract This study deals with the comparison of impurity behaviour in pellet and gas fuelled JET-ITER like wall pulses aim finding mechanisms leading to generally observed higher concentration tungsten plasmas. In fact, is main high- Z JET-ILW plasmas responsible for most radiative losses plasma core. Analysis experimental data pertaining at different currents, input power electron densities integrated by numerical modelling self-consistent fluid transport code COREDIV. Experimentally,...
Experimental campaigns at the Joint European Torus with an ITER-like Be/W wall pure deuterium (D), tritium (T), and deuterium–tritium (DT) were a unique opportunity to explore various aspects related ITER operation. One of most important challenges in recent years was development hybrid scenario for D-T, based on reference plasmas. This kind scenario, one foreseen ITER, is characterized by low current plasma high normalized beta βN factor compared parallel optimized baseline [Hobirk et al.,...
The work presents the recent outcome of research on Joint European Torus with ITER-like wall (JET-ILW) concerning Be, mid-Z (Ni, Cu, Fe), and high-Z (W) impurities for a selection Neutral Beam Injection-heated, ELMy H-mode pulses using visible vacuum–ultraviolet spectroscopy together bolometry diagnostic. investigation is focused evaluation plasma triangularity (δ) impact impurity radiation in hydrogen (H), deuterium (D), tritium (T), deuterium–tritium (DT) plasmas described [P. A....
Abstract The behaviour of impurities in fusion plasmas is crucial importance for achieving sustained reactions, and understanding similarities differences between Deuterium (D) Tritium (T) needed to assess potential changes from DD DT ITER future reactors. first dimensionless dimensional isotope identity experiments L-mode were conducted at the JET W/Be wall. In approach, discharges with matched ρ ∗, ν β n , q T e / i compared emphasize direct effects, while approach engineering parameters...
Abstract The aim of this paper is to numerically study the influences impurities on high power hybrid discharges in JET ITER-like wall (ILW) configuration DD and deuterium–tritium (DT) scenarios. Numerical simulations with COREDIV code 32 MW auxiliary heating, 2.2 MA plasma current 2.8 T toroidal magnetic field ILW corner are presented. In five impurity species used: intrinsic: beryllium (Be) nickel (Ni) from side walls, helium (He) DT reaction, tungsten (W) divertor extrinsic neon (Ne) or...