A5000080028- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Fusion materials and technologies
- Superconducting Materials and Applications
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Solar and Space Plasma Dynamics
- Nuclear reactor physics and engineering
- Plasma Diagnostics and Applications
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Physics of Superconductivity and Magnetism
- Quantum chaos and dynamical systems
- Dust and Plasma Wave Phenomena
- Laser-induced spectroscopy and plasma
- Astro and Planetary Science
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Gamma-ray bursts and supernovae
- Vibration and Dynamic Analysis
- Advanced Data Storage Technologies
- Ocean Waves and Remote Sensing
- Combustion and Detonation Processes
- Electrostatic Discharge in Electronics
- Fluid Dynamics Simulations and Interactions
Chalmers University of Technology
1986-2024
European Commission
2012-2024
Royal Military Academy
2020
Directorate-General for Research and Innovation
2009-2018
Culham Science Centre
1998-2016
CEA Cadarache
2002-2011
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2002-2011
École Polytechnique Fédérale de Lausanne
2007-2011
Ghent University
2007-2008
Tekes
2007
CRONOS is a suite of numerical codes for the predictive/interpretative simulation full tokamak discharge. It integrates, in modular structure, 1D transport solver with general 2D magnetic equilibria, several heat, particle and impurities models, as well momentum sources. This paper gives first comprehensive description suite: overall structure code, main available details on workflow implementation. Some examples applications to analysis experimental discharges predictions ITER scenarios are...
The scaling of the energy confinement in H mode plasmas with different hydrogenic isotopes (hydrogen, deuterium, DT and tritium) is investigated JET. For ELM-free modes thermal time τth found to decrease weakly isotope mass (τth ∼M-0.25±0.22), whilst ELMy shows practically no dependence ∼M0.03±0.1). Detailed local transport analysis reveals that edge region increases strongly mass, whereas core decreases (τthcore ∝ M-0.16), approximate agreement theoretical models gyro-Bohm type (τgB ∼M-0.2).
Parametric scalings of the intrinsic (spontaneous, with no external momentum input) toroidal rotation observed on a large number tokamaks have been combined an eye towards revealing underlying mechanism(s) and extrapolation to future devices. The velocity has found increase plasma stored energy or pressure in JET, Alcator C-Mod, Tore Supra, DIII-D, JT-60U TCV, decrease increasing current some these cases. Use dimensionless parameters led roughly unified scaling MA ∝ βN, although variety Mach...
Comparisons between time dependent simulations and experiments in ion cyclotron heated plasmas the JET tokamak have been made. A code, PION-T, has used to simulate heating. The scenario that analysed is minority heating of hydrogen a deuterium plasma. Two measured quantities compared with calculations, namely anisotropic plasma energy content 2.4 MeV neutron flux from (D,D) reactions. versions PION-T code used, one zero banana width which simplified model for taking finite drift orbits into...
Analysis of MHD activity in pellet enhanced performance (PEP) pulses is used to determine the position rational surfaces associated with safety factor q. This gives evidence for negative shear central region plasma. The plasma equilibrium calculated from measured q values yields a Shafranov shift reasonable agreement experimental value about 0.2 m. corresponding current profile has two large off-axis maxima bootstrap electron temperature and density measurements. A transport simulation shows...
METIS is a numerical code aiming at fast full tokamak plasma analyses and predictions. It combines 0D scaling-law normalised heat particle transport with 1D current diffusion modelling 2D equilibria. contains several heat, impurities models, as well particle, momentum sources, which allow faster than real time scenario simulations. This paper gives first comprehensive description of the suite: overall structure code, main available details on simulation workflow implementation. Some examples...
Abstract The fast-ion distribution function in fusion plasmas can be inferred by inverting Doppler-shifted measurements from diagnostics. full parametrised three constants of motion with the addition a binary index. However, limited number measurements, cogent prior information must added to regularise inverse problem, enabling reconstruction function. In this paper, we demonstrate how incorporate wave-particle interactions ion cyclotron range frequencies (ICRF) as future ITER tokamak test...
Results are presented from a series of dedicated experiments carried out on JET in tritium, DT, deuterium and hydrogen plasmas to determine the dependence H mode power threshold plasma isotopic mass. The Pthr ∝ Aeff-1 scaling is established over whole range. This result makes it possible for fusion reactor with 50:50 DT mixture access regime about 20% less than that needed DD mixture. first systematic measurements necessary transition type I ELM regime, which occurs after mode, also...
The first measurements of toroidal rotation the bulk plasma during purely ion cyclotron resonance frequency (ICRF) heated H-modes on JET tokamak are reported. Substantial acceleration in direction current occurs at transition into H-mode. In present paper relationship between and improved confinement H-mode is investigated. We conclude that dominant driving mechanism for pressure gradient.
Scenarios of steady-state, fully non-inductive current in Tore Supra are predicted using a package simulation codes (CRONOS). The plasma equilibrium and transport consistently calculated with the deposition power. achievement high injected energy discharges up to 1 GJ is shown. Two main scenarios considered: low density regime 90% driven by lower hybrid waves—lower drive (LHCD)—and combining LHCD ion cyclotron resonance heating bootstrap fraction 25%. predictive simulations existing also reported.
In this paper, the basic theory of runaway electron production is reviewed and recent progress discussed. The mechanisms primary secondary generation electrons are described their dynamics during a tokamak disruption analysed, both in simple analytical model through numerical Monte Carlo simulation. A criterion for when these generate significant current derived, first self-consistent simulations kinetics presented. Radial cross-field diffusion shown to inhibit avalanches, as indicated...
Reactor relevant ICRH scenarios have been assessed during DT experiments on the JET tokamak using H mode divertor discharges with ITER-like shapes and safety factors. Deuterium minority heating in tritium plasmas was demonstrated for first time. For 9% deuterium, an power of 6 MW gave 1.66 fusion from reactions between suprathermal deuterons thermal tritons. The Q value steady state discharge reached 0.22 length RF flat-top (2.7 s), corresponding to three plasma energy replacement times....
An overview of JET experimental results in DT plasmas directly relevant to ITER modes operation is presented. Experiments D:T mixtures varying from 100:0 10:90 and those carried out hydrogen show that the H mode threshold power has an approximately inverse isotope mass dependence. Matching some key dimensionless parameters values, similarity experiments with shape safety factor q global energy confinement time practically independent isotopic (~A0.03±0.08), where A atomic hydrogenic species....
Ion cyclotron resonance heating (ICRH) experiments have been carried out in JET D-T plasmas using scenarios applicable to reactors. Deuterium minority tritium is used for the first time and produces 1.66 MW of fusion power an ICRH 6 MW. The $Q$ value 0.22, which a record steady state discharges. Fundamental $\mathrm{He}{}^{3}$ ICRH, both 50:50 dominated plasmas, generates strong bulk ion temperatures up 13 keV. Second harmonic seen heat mainly electrons as expected conditions. All three...
Quasi-steady operation has been achieved at JET in the high-confinement regime with internal transport barriers (ITBs). The ITB maintained up to 11 s. This duration, much larger than energy confinement time, is already approaching a current resistive time. high-performance phase limited only by plant constraints. radial profiles of thermal electron and ion pressures have steep gradients typically mid-plasma radius. A large fraction non-inductive (above 80%) sustained throughout poloidal beta...
Third-harmonic ion-cyclotron-resonance heating of ${}^{4}\mathrm{He}$-beam ions has produced for the first time on JET tokamak high-energy populations ${}^{4}\mathrm{He}$ to simulate 3.5 MeV fusion-born alpha (\ensuremath{\alpha}) particles. Acceleration energy range is confirmed by \ensuremath{\gamma}-ray emission from nuclear reaction ${}^{9}\mathrm{Be}(\ensuremath{\alpha},n\ensuremath{\gamma}){}^{12}\mathrm{C}$ and excitation Alfv\'en eigenmodes. Concomitant electron sawtooth...
The first experimental observation of a radio frequency (rf) wave-induced particle pinch trapped ions has been made in experiments at the Joint European Torus with nearly on-axis high power toroidally asymmetric ICRF (ion cyclotron range frequencies) heating. Significant differences have detected discharges when waves directed opposite toroidal directions. In particular, fast-ion-driven Alfv\'en eigenmode activity, sawtooth behavior, and proton distribution functions found to be strongly...
Quasistationary operation has been achieved on the Joint European Torus tokamak in internal-transport-barrier (ITB) scenarios, with discharge time limited only by plant constraints. Full current drive was obtained over all high performance phase using lower hybrid drive. For first feedback control total pressure and electron temperature profile implemented using, respectively, neutral beams ion-cyclotron waves. Although impurity accumulation could be a problem steady state ITBs, these...
Monte Carlo operators for the orbit-averaged Fokker–Planck equation describing collisions and wave–particle interaction are constructed. Special emphasis is put on ion-cyclotron-resonance heating of tokamaks, but results applicable to general quasilinear processes in arbitrary magnetic configurations which particle motion integrable. All effects nonstandard orbit topology, such as large widths, fully taken into account. The may be used simulating, e.g., radio-frequency heating, wave-driven...
Gamma-ray images of fast D- and 4He-ions accelerated with third-harmonic ion-cyclotron-resonance heating 4He-beam were simultaneously recorded for the first time in JET tokamak experiments dedicated to investigation burning plasmas 3.5 MeV fusion alpha (α) particles. Gamma (γ) rays, born as a result nuclear reactions, 9Be(4He, nγ)12C 12C(D, pγ)13C, between ions main plasma impurities, are measured using two-dimensional multicollimator spectrometer array, which distinguishes γ-rays from...
Observations of bulk plasma rotation in radio frequency (RF) heated JET discharges are reported. This study is concentrated on RF L-mode plasmas. In particular, the toroidal profiles plasmas by ion cyclotron resonance (ICRF) waves and lower hybrid (LH) have been analysed. It first time that with LH measured dedicated discharges. found outer region co-current direction irrespective heating scenario. An interesting feature profile appears to be hollow many at low current, but a current itself...
The kinetic theory of runaway electron avalanches caused by close Coulomb collisions is extended to account for radial diffusion. This found slow down the growth avalanches. An approximate analytical formula rate derived and verified a three-dimensional Monte Carlo code constructed this purpose. As poloidal magnetic flux that available induce an electric field in tokamak limited, can be prevented altogether sufficiently strong requisite fluctuation level sensitive mode structure speed...
Ion cyclotron resonance heating in a toroidal plasma not only increases the perpendicular energy of resonating ions but also results their spatial transport. Depending on direction propagation waves, will either drift inwards or outwards giving rise to an RF induced rotation with torque component co-current counter-current directions, respectively. It is found that transport by field, topology ion orbits and wave field consistent absorption are important for determining distribution function...