G. Telesca
A5022841778- Magnetic confinement fusion research
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Plasma Diagnostics and Applications
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Superconducting Materials and Applications
- Nuclear reactor physics and engineering
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- High-Energy Particle Collisions Research
- Medical Imaging Techniques and Applications
- Structural Engineering and Materials Analysis
- Electron and X-Ray Spectroscopy Techniques
- Laser Design and Applications
- Meteorological Phenomena and Simulations
- Gyrotron and Vacuum Electronics Research
- Silicon and Solar Cell Technologies
- Electrostatic Discharge in Electronics
- Numerical methods in inverse problems
- Nuclear Engineering Thermal-Hydraulics
- Fault Detection and Control Systems
- Particle Accelerators and Free-Electron Lasers
- Advanced Data Storage Technologies
- Anomaly Detection Techniques and Applications
Institute of Plasma Physics and Laser Microfusion
2019-2024
Culham Centre for Fusion Energy
1993-2024
Culham Science Centre
2009-2024
Royal Military Academy
1979-2020
Ghent University
2006-2019
Forschungszentrum Jülich
1994-2009
Queen's University Belfast
2009
National Agency for New Technologies, Energy and Sustainable Economic Development
2001-2003
Laboratoire de Physique des Plasmas
1979-1992
Edge radial electric fields were induced in the edge of TEXTOR tokamak by means a polarization electrode order to study their influence on plasma profiles and its confinement. The studies include generation H-mode behaviour with either positive or negative polarity. Particle confinement (τp) deuterium impurity ions as well energy (τE) are investigated. For which remain below threshold for L-H transition, an interesting regime reduced particle without noticeable loss is found. A strong...
Stationary high energy confinement is observed on TEXTOR-94 for times limited only by the flux swing of transformer using strong edge radiation cooling. Necessary tools are feedback control radiated power and plasma content. At highest densities obtained (up to 1.2 Greenwald limit), exceeds edge-localized-mode-free H-mode scaling ITERH93-P more than 20%. β limits reached with fH89/qa≈0.6. No detrimental effect seeded impurity seen. These discharges meet many conditions necessary a fusion...
Impurity injection in the JET ELMy H-mode regime has produced high-confinement, quasi-steady-state plasmas with densities close to Greenwald density. However, at large Ar densities, a sudden loss of confinement is observed. A possible correlation between and observed MHD phenomena, both core edge plasma, was considered. The degradation coincided impurity profile peaking following disappearance sawtooth activity. In addition, density analysis confirmed that central modes prevented peaking....
The first results of the Dynamic Ergodic Divertor in TEXTOR, when operating m/n=3/1 mode configuration, are presented. deeply penetrating external magnetic field perturbation this configuration increases toroidal plasma rotation. Staying below excitation threshold for m/n=2/1 tearing mode, rotation is always direction current, even if projection rotating opposite direction. observed consistent with a radial electric field, generated by an enhanced electron transport ergodic layers near...
Improved confinement is achieved on TEXTOR under high power conditions (up to 4 MW of additional heating with NBI-co+ICRH, NBI-co+counter or NBI-co+counter+ICRH) edge radiative cooling employing silicon neon as the radiating impurities. It shown that in quasi-stationary up 85% input can be radiated. Such fractions offer possibility utilizing these techniques facilitate exhaust problem for a Tokamak reactor. Discharges exhibit enhanced properties at densities, e.g. central line averaged...
An overview of the results obtained so far for radiative I-mode regime on upgraded Torus Experiment Technology Oriented Research (TEXTOR-94) [Proceedings 16th IEEE Symposium Fusion Engineering (Institute Electrical and Electronics Engineers, Piscataway, NJ, 1995), Vol. 1, p. 470] is given. This under quasistationary conditions with edge neon seeding in a pumped limiter tokamak circular cross section. It combines high confinement β (up to normalized beta, βn=2) low q values (down qa=2.8)...
One of the most severe problems for fusion reactors is power load on plasma facing components. The challenge to develop operation scenarios, which combine sufficient energy confinement with benign heat loads radiative type-III ELMy H-mode seems a possible solution such an integrated ITER scenario. Nitrogen seeded H-modes standard inductive scenario and high beta stationary hybrid are investigated respect their transient steady-state fluxes divertor, properties, edge operational space, core...
This paper addresses the issues of impurity behaviour during argon seeding experiments in JET, which and D2 have been simultaneously puffed ELMy H-mode discharges to reach high density regimes, maintaining good confinement properties throughout plasma discharge. The analysis is based mainly on a 1-D diffusion model, evaluates transport coefficients three experimental scenarios.
Recent progress towards obtaining high density and confinement in JET as required for the ITER reference scenario at Q = 10 is summarized. Plasmas with simultaneous H98(y,2) 1 densities up to n/nGW~1 are now routinely obtained. This has been possible (i) by using plasmas (δ~0.5) medium (δ~0.3-0.4) triangularity sufficient heating power maintain Type I ELMs, (ii) impurity seeded low (δ⩽0.2) triangularity, (iii) an optimized pellet injection sequence, maintaining energy raising density, (iv)...
High-Z materials as tungsten are intended to be used in future fusion reactors due their low sputtering rates and high melting points. In this context the important question is whether use of high-Z compatible with concept a cold radiative boundary. To investigate local release transport behaviour impurities, Mo W test limiters were auxiliary heated discharges under different radiation scenarios neon seeding. addition, laser blow-off well xenon gas puffing performed. some particular...
An overview is given of recent advances toward the realization high density, confinement plasmas with radiating mantles in limiter and divertor tokamaks worldwide. Radiatively improved mode discharges on Torus Experiment for Technology Oriented Research 94 (TEXTOR-94) [Proceedings 16th IEEE Symposium Fusion Engineering, 1995 (Institute Electrical Electronics Engineers, Piscataway, NJ, 1995), p. 470] have recently been obtained at trans-Greenwald densities (up to n̄/nGW=1.4) free edge...
ELMy H-mode experiments at JET in 2000/mid-2002 have focused on discharges with normalized parameters for plasma density, energy confinement and beta similar to those of the ITER QDT = 10 reference regime (n/nGW ∼ 0.85, H98(y,2) 1, βN 1.8). plasmas been realized reaching or even exceeding steady-state conditions (up 5 s 12 τE) a reproducible way only limited by duration additional heating phase. These results obtained (a) highly triangular plasmas, increasing average triangularity δ towards...
Scaling to larger tokamaks of high confinement plasmas with radiating edges, induced by impurities, is being studied through internationally collaborative experiments on JET. In campaigns till the end 2000, three different regimes have been explored. A small number limiter L-mode discharges seeded neon most closely repeated approach used TEXTOR-94, but collisionality and particle transport in JET impede central peaking density associated improved confinement. Divertor L-modes at intermediate...
The design value for ITER is based on operation at n/nGW = 0.85, βn 1.8 and H98(y,2) 1. These values have been routinely achieved in JET argon seeded ELMy H-mode discharges different divertor configurations with triangularities. Two main scenarios are emerging from the experiments.
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...
In anticipation of revised operational limits accompanying upgrade the JET tokamak to an all-metal, ITER-like wall, systematic studies have been conducted moderating divertor heat load in type I ELMy H-mode by enhanced deuterium fuelling and seeding with extrinsic impurities neon or nitrogen. These were found differ mainly roughly ten times higher level nitrogen than presently required approach outboard detachment, their effects upon ELMs. With either species up input power ?17?MW, strongly...
Abstract In this paper we present results of numerical simulations nitrogen seeded JET discharges. particular, have benchmarked the code against type III ELMy pulses. addition to recovering main discharge parameters, interplay between and intrinsic carbon is also reproduced. Predictions for discharges with higher plasma current I p = 3.5 MA different input powers (14 < P aux 23 MW) demonstrate that it possible achieve high radiation fractions (> 80%) simultaneously reduce both...
A stationary high level of edge radiation ( gamma =Prad/Ptot up to ~90% with peak ~1 MW/m3) has been obtained in TEXTOR by using silicon and/or neon as radiating impurities. The confinement and neutron reactivity are not degraded but can even be improved at plasma densities. Stationary reactor relevant heating radiated power flows a figure merit fH/qa=0.6 have achieved. interpretation these results shows reduction the bulk transport presence cooling. properties radiatively cooled discharges...
The radiative improved mode obtained on the limiter tokamak TEXTOR-94 combines possibility of power exhaust by a radiating plasma boundary (with fraction radiated with respect to total input up 90% neon or argon cooling) energy confinement (as good as in ELM-free H-mode divertor tokamaks) at high densities (line-averaged central-electron density equal even above Greenwald limit ) quasi-stationary discharges. An overview is given substantial changes plasma-edge properties occurring levels ....
After the first demonstration of successful operation with ion cyclotron resonance heating (ICRH) on TEXTOR using an antenna without Faraday shield (FS), a further comparison FS and has been made over wide range plasma conditions (including improved confinement regime TEXTOR), in zero phase pi operation, various scenarios. No restriction operational was found to exist for screenless antenna. A theoretical analysis shows that side limiters are sufficient protect conductor from front can take...