A5003335603- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Fusion materials and technologies
- Superconducting Materials and Applications
- Ionosphere and magnetosphere dynamics
- Plasma Diagnostics and Applications
- Laser-Plasma Interactions and Diagnostics
- Nuclear Issues and Defense
- Space Science and Extraterrestrial Life
- Gyrotron and Vacuum Electronics Research
- Nuclear reactor physics and engineering
- Cold Fusion and Nuclear Reactions
- Dust and Plasma Wave Phenomena
- Atomic and Molecular Physics
- Solar and Space Plasma Dynamics
- Antenna Design and Analysis
- Physics of Superconductivity and Magnetism
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Magnetic Bearings and Levitation Dynamics
- Global Energy and Sustainability Research
- Electromagnetic Compatibility and Measurements
- Diverse Interdisciplinary Research Studies
- Geomagnetism and Paleomagnetism Studies
CEA Cadarache
2007-2023
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2007-2023
ITER
2011-2023
Institut de Recherche sur la Fusion par Confinement Magnétique
1998-2022
Royal Military Academy
2020
Korea Institute of Fusion Energy
2011
Southwestern Institute of Physics
2011
National Agency for New Technologies, Energy and Sustainable Economic Development
2011
Culham Centre for Fusion Energy
2011
Culham Science Centre
2011
Significant progress has been made in the area of advanced modes operation that are candidates for achieving steady state conditions a fusion reactor. The corresponding parameters, domain operation, scenarios and integration issues discussed this chapter. A review presently developed scenarios, including discussions on operational space, is given. heating current drive recent years, especially off-axis drive, which essential achievement required profile. actuators necessary to produce...
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...
Mastering nuclear fusion, which is an abundant, safe, and environmentally competitive energy, a great challenge for humanity. Tokamak represents one of the most promising paths toward controlled fusion. Obtaining high-performance, steady-state, long-pulse plasma regime remains critical issue. Recently, big breakthrough in steady-state operation was made on Experimental Advanced Superconducting (EAST). A with world-record pulse length 1056 s obtained, where density divertor peak heat flux...
The 2014–2016 JET results are reviewed in the light of their significance for optimising ITER research plan active and non-active operation. More than 60 h plasma operation with first wall materials successfully took place since its installation 2011. New multi-machine scaling type I-ELM divertor energy flux density to is supported by principle modelling. relevant disruption experiments modelling reported a set three mitigation valves mimicking setup. Insights L–H power threshold Deuterium...
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...
The experimental programme of Tore Supra, the largest superconducting tokamak in world (a = 0.72 m, R 2.4 Ip < 1.7 MA, BT 4.5 T) was devoted 2003 to studying heat removal capability and particle exhaust steady-state fully non-inductive current drive discharges simultaneously. This required both advanced technology integration real-time plasma control. In particular, an improvement position within a range few millimetres, new controls radio frequency power various actuators built around...
A 20 MW/5 GHz lower hybrid current drive (LHCD) system was initially due to be commissioned and used for the second mission of ITER, i.e. Q = 5 steady state target. Though not part currently planned procurement phase, it is now under consideration an earlier delivery. In this paper, both physics technology conceptual designs are reviewed. Furthermore, appropriate work plan also developed. This design, R&D, installation a MW LHCD on ITER follows Scientific Technical Advisory Committee...
The global energy confinement of combined ohmic and lower hybrid driven TORE SUPRA plasmas has been analysed at various densities. In contradiction to the L mode ITER scaling law, this analysis indicates that time depends strongly on plasma density. Furthermore, thermal electron content steady state discharges is found be in good agreement with Rebut-Lallia-Watkins (RLW) law. Current ramp experiments show an enhancement internal inductance, li. These results have extended regimes current...
In 2003, the performance of 'hybrid' regime was successfully validated in JET experiments up to βN = 2.8 at low toroidal field (1.7 T), with plasma triangularity and normalized Larmor radius (ρ*) corresponding identical ASDEX Upgrade discharges. Stationary conditions have been achieved fusion figure merit ( ) reaching 0.42 q95 3.9. The discharges show similar MHD, edge current profile behaviour, when compared Upgrade. addition, extended hybrid scenario operation higher 2.4 T lower ρ* towards...
A detailed study of lower hybrid current drive (LHCD) in ITER is provided, focusing on the wave propagation and mechanisms. combination ray-tracing Fokker–Planck calculations are presented for various plasma scenarios, frequency polarization. The dependence driven location power deposition upon coupled spectrum systematically determined, order to set objectives antenna design. respective effects finite-power levels, magnetic trapping, spectra accounted quantitatively estimated. sensitivity...
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...
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...
The fusion performance of JET plasmas can be enhanced by the generation internal transport barriers. influence theq-profile shape in local and global plasma has been investigated cases where core magnetic shear ranges from small positive to large negative. Internal barriers extending radii effective raising plasma. It is found that such tend generated more easily if q-profile contains a region negative shear. formation favoured neutral beam injection compared with ion cyclotron resonance...
A new ITER-relevant lower hybrid current drive (LHCD) launcher, based on the passive-active-multijunction (PAM) concept, was brought into operation Tore Supra tokamak in autumn 2009. The PAM launcher concept designed view of ITER to allow efficient cooling waveguides, as required for long pulse operation. In addition, it offers low power reflection close cut-off density, which is very attractive ITER, where large distance between plasma and wall may bring density front values. first...
A new model based on a combination of Bohm-like term plus gyro-Bohm-like is proposed for the electron and ion heat diffusivity in L mode regime, which commonest regime operation tokamaks. This derived using dimensionless analysis technique taking into account indications scaling laws global confinement time other experimental constraints diffusivity. The has been successfully tested against data from several different experiments ITER database local Tore Supra database. Statistical shown it...
The two-dimensional (2D) edge plasma density distribution in the scrape off layer magnetically connected to ion cyclotron resonance heating (ICRH) antennae is studied experimentally and numerically tokamak Tore Supra. A local decrease front of loaded ICRH antenna (“pump-out” effect) demonstrated by Langmuir probe measurements a low recycling regime. An up–down asymmetry heat-flux erosion also observed, associated with poloidal variations density. These redistributions are ascribed an E×B...
The question of heating a tokamak plasma by means electromagnetic waves in the ion cyclotron range frequencies (ICRF) is considered perspective large rf powers and low collisionality regime. In such case, quasilinear theory (QLT) validated Hamiltonian dynamics wave–particle interaction which exceeds threshold intrinsic stochasticity. represented evolution set three canonical action angle variables well adapted to magnetic configuration. This approach allows derivation diffusion coefficient...
This paper considers the heating mix of ITER for two main scenarios. Presently, 73 MW absorbed power are foreseen in 20/33/20 ECH, NBI and ICH. Given a sufficient edge stability, Q = 10—the goal scenario 2—can be reached with 40 irrespective method but depends sensitively inter alia on H-mode pedestal temperature, density profile shape characteristics impurity transport. ICH preferentially heats ions would contribute specifically ΔQ < 1.5. The success 5 steady-state 4 reduced current...
In optimized shear plasmas in the Joint European Torus [P. H. Rebut and B. E. Keen, Fusion Technol. 11, 13 (1987)], safety factor (q) profiles with negative magnetic are produced by applying lower hybrid (LH) waves during plasma current ramp-up phase. These produce a barrier to electron energy transport. The radius at which is located increases LH wave power. When heated high power from ion cyclotron resonance heating neutral beam injection, they can additionally transient internal transport...
During noninductively driven discharges in the Tore Supra tokamak, steady sinusoidal oscillations of central electron temperature, lasting as long 2 min, have been observed for first time. Having no helical structure, they cannot be ascribed to any known MHD instability. The most plausible explanation this new phenomenon is that plasma current density and temperature evolve a nonlinearly coupled predator-prey system. This interpretation supported by numerical solution resistive diffusion...
The recent development of real-time measurements and control tools in JET has enhanced the reliability reproducibility relevant ITER scenarios. Diagnostics such as charge exchange, interfero-polarimetry, electron cyclotron emission have been upgraded for measurements. In addition, processes like magnetic equilibrium q profile reconstruction developed applied successfully experiments using model based techniques. Plasma operation against magnetohydrodynamic instabilities are also benefiting...
We present the results of recent experiments related to real-time control internal transport barriers (ITBs) in JET. Using a simple criterion characterize ITB existence, location and strength, we have successfully controlled for first time radial electron temperature profile within ITB. The dimensionless variable used algorithm - ratio ion gyro-radius local gradient scale length is measure normalized characterizes satisfactorily main features with relatively low computational cost. show...