A5000597047- Magnetic confinement fusion research
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Astro and Planetary Science
- Superconducting Materials and Applications
- Laser-Plasma Interactions and Diagnostics
- Fusion materials and technologies
- Plasma Diagnostics and Applications
- Particle accelerators and beam dynamics
- Nuclear reactor physics and engineering
- Astronomical Observations and Instrumentation
- Nuclear physics research studies
- Stellar, planetary, and galactic studies
- Atomic and Molecular Physics
- Quantum chaos and dynamical systems
- European and International Law Studies
- Material Science and Thermodynamics
- Geomagnetism and Paleomagnetism Studies
- Atomic and Subatomic Physics Research
- International Arbitration and Investment Law
- Astronomy and Astrophysical Research
- Magnetic properties of thin films
- Gas Dynamics and Kinetic Theory
- Radiation Detection and Scintillator Technologies
- Elasticity and Wave Propagation
Kurchatov Institute
2009-2023
Moscow State Institute of International Relations
2018-2021
École Polytechnique Fédérale de Lausanne
2000-2009
Princeton Plasma Physics Laboratory
2007
Centre National de la Recherche Scientifique
2007
Institut National de Physique Nucléaire et de Physique des Particules
2007
National Institute for Fusion Science
2003-2005
Plasma (Russia)
2000-2003
Energy Institute
2002
Numerical results for the three mono-energetic transport coefficients required a complete neoclassical description of stellarator plasmas have been benchmarked within an international collaboration. These are flux-surface-averaged moments solutions to linearized drift kinetic equation which determined using field-line-integration techniques, Monte Carlo simulations, variational method employing Fourier–Legendre test functions and finite-difference scheme. The benchmarking has successfully...
Compact optimized stellarators offer novel solutions for confining high-β plasmas and developing magnetic confinement fusion. The three-dimensional plasma shape can be designed to enhance the magnetohydrodynamic (MHD) stability without feedback or nearby conducting structures provide drift-orbit similar tokamaks. These configurations possibility of combining steady-state low-recirculating power, external control, disruption resilience previous with low aspect ratio, high β limit, good...
Fast particles in fusion plasmas may drive Alfvén modes unstable leading to fluctuations of the internal electromagnetic fields and potential loss particles. Such instabilities can have an impact on performance wall-load machines with burning such as ITER. A linear benchmark for a toroidal eigenmode (TAE) is done 11 participating codes broad variation physical well numerical models. reasonable agreement around 20% has been found growth rates. Also, eigenfunctions mode frequencies satisfying....
A comparative study of energy transport for medium- to high-density discharges in the stellarator-heliotrons TJ-II, W7-AS and LHD is carried out. The specific discharge parameters are chosen apply a recently concluded benchmarking neoclassical (NC) coefficients (Beidler et al 2011 Nucl. Fusion 51 076001) perform this validation study. In contrast previous experiments at low densities which electron was predominant (Yokoyama 2007 47 1213), current also exhibit significant ion transport. As it...
A quasi-isodynamic stellarator with poloidally closed contours of the magnetic field strength B (Mikhailov 2002 Nucl. Fusion 42 L23) has been obtained by an integrated physics optimization comprising MHD and neoclassical theory. For a configuration six periods aspect ratio approximately 12, main result is attainability essentially MHD-stable high-beta ([beta] approximate to 0.085) plasma low transport, vanishing bootstrap current in long-mean-free-path regime excellent a-particle confinement.
New experimental observations of the plasma potential using heavy ion beam probe diagnostic are presented together with a theoretical description formation electric field Er in T-10 circular tokamak (B0 = 1.5–2.5 T, R 1.5 m, 0.3 m). Ohmically heated (OH) deuterium plasmas main parameters , Te(0) < 1.3 keV, Ti(0) 0.6 keV characterized by negative φ(ρ) maximum values φ(6 cm) −1400 V respect to wall. The profile monotonically increases towards edge. A density rise due gas puff is accompanied...
Key physics issues in the design of a high- quasi-axisymmetric stellarator configuration are discussed. The goal study is compact with aspect ratio comparable to that tokamaks and good transport stability properties. Quasi-axisymmetry has been used provide drift trajectories. Ballooning stabilization accomplished by strong axisymmetric shaping, yielding whose core second regime for ballooning modes. A combination externally generated shear non-axisymmetric corrugation plasma boundary...
The (n, gamma) cross section of 206Pb has been measured at the CERN n_TOF facility with high resolution in energy range from 1 eV to 600 keV by using two optimized C6D6 detectors. In investigated interval about 130 resonances could be observed, which 61 had enough statistics reliably analyzed via R-matrix analysis code SAMMY. Experimental uncertainties were minimized, particular respect (i) angular distribution effects prompt capture gamma-rays, and (ii) TOF-dependent background due...
Strategies for the improvement of quasiaxisymmetric stellarator configurations are explored. Calculations equilibrium flux surfaces candidate also presented. One optimization strategy is found to generate with improved neoclassical confinement, simpler coils lower current density, and surface quality relative previous designs. The calculations find significant differences in extent islands stochastic regions between configurations. (These do not incorporate predicted beneficial effects...
The possibility of fulfilling the condition poloidal closure contours second adiabatic invariant for all reflected particles is studied systems with poloidally closed magnetic field B on surfaces through computational stellarator optimization. It shown that by adjusting geometry this possible in a major fraction plasma volume. most salient characteristic (as compared to previous quasi-isodynamic configurations) axis whose curvature vanishes cross sections an extremum and renders...
A Hamiltonian/Lagrangian theory to describe guiding centre orbit drift motion which is canonical in the Boozer coordinate frame has been extended include full electromagnetic perturbed fields anisotropic pressure 3D equilibria with nested magnetic flux surfaces. redefinition of velocity eliminate due finite equilibrium radial and choice a gauge condition that sets component vector potential zero are invoked guarantee angular coordinates retain structure. The momenta identified particle...
Neoclassical transport and α particle confinement are analysed for three 3-D reactor designs - the QAS3, ST/sphellamak hybrid sphellamak using VENUS code. It is observed that neither QAS3 nor truly a quasi-axisymmetric configuration. Thus governed by helical deformation of magnetic field strength, these configurations do not effectively confine trapped particles. On other hand, nearly isodynamic structure in plasma core, which leads to almost perfect confinement, neoclassical very similar...
A new three-dimensional code, VENUS+δf, for neoclassical transport calculations in nonaxisymmetric toroidal systems is presented. Numerical drift orbits from the original VENUS code and δf method developed tokamak are combined. The first results obtained with VENUS+δf compared theory different collisional regimes a JT-60 test case both monoenergetic particles Maxwellian distribution; good agreement found. Successful benchmarking of bootstrap current Wendelstein 7-X configuration DKES...
A Hamiltonian formulation of the guiding center drift orbits is extended to pressure anisotropy and field perturbations in axisymmetric systems. The Boozer magnetic coordinates are shown retain canonical properties anisotropic plasmas with finite electrostatic electromagnetic perturbed fields that solely affect parallel component vector potential. equations motion developed coordinate frame satisfied by direct verification velocities. numerical application illustrates significance retaining...
The ideal magnetohydrodynamic (MHD) stability of the National Compact Stellarator Experiment (NCSX) is extensively analyzed using most advanced three-dimensional MHD codes. It shown that NCSX stable to finite-n modes, including vertical mode, external kink modes and ballooning modes. However, high-n peak near plasma edge are found be weakly unstable. A global calculation shows significantly more than local infinite-n
Normalized bootstrap current coefficients are calculated for Large Helical Device (LHD, Japan) plasma configurations with different magnetic axis positions using the VENUS+δf code [Fusion Sci. Technol. 50, 440 (2006)]. The dependences on collisionality regimes (over full experimental range of LHD discharges) and radii presented. comparison VENUS+δf, SPBSC DKES codes results is shown. approach to discussed. effect iota = 1 islands considered.
To evaluate the bootstrap current in nonaxisymmetric toroidal plasmas quantitatively, a δf Monte Carlo method is incorporated into moment approach. From drift-kinetic equation with pitch-angle scattering collision operator, and neoclassical conductivity coefficients are calculated. The viscosity evaluated from these two monoenergetic transport coefficients. Numerical results obtained by for model heliotron reasonable agreement asymptotic formulae variational principle.
Bootstrap current calculations with the neoclassical SPBSC and VENUS+δf codes have been performed on experimental Large Helical Device (LHD, NIFS, Japan) configurations different magnetic axis positions simplified plasma density temperature profiles. In this paper, we use experimentally obtained electron profiles for LHD discharges #61863 #82582 to compute corresponding magnetohydrodynamic equilibrium states collisional frequency. An improved operator has implemented into code. The...
The equilibrium and linear fluid Magnetohydrodynamic (MHD) stability in an inward-shifted large helical device heliotron configuration are investigated with the 3D ANIMEC TERPSICHORE codes, respectively. A modified slowing-down distribution function is invoked to study anisotropic pressure conditions. An appropriate choice of coefficients exponents allows simulation neutral beam injection which angle varied from parallel perpendicular. analysis concentrates on application...
A Hamiltonian formulation of the relativistic guiding center drifts is extended to anisotropic pressure plasmas. The magnetic coordinates devised by Boozer are adapted model and retain canonical properties for two-dimensional three-dimensional toroidal plasma equilibria including finite electrostatic perturbations provided that any electromagnetic perturbation only alters parallel component vector potential. mapping technique from arbitrary flux outlined. direct evaluation drift velocity...
In current-free stellarators, the parallel current density is normally too weak to drive global external kink modes. However, at finite values of β, bootstrap (BC) can provide sufficient free energy trigger this class mode in some stellarator systems. The effect BC collisionless 1/ν regime has been investigated several different types reactor systems all with a volume V∼1000 m3. quasiaxisymmetric and quasihelically symmetric large β cause low order resonances move into emerge out plasma...
Properties of toroidal Alfvén eigenmodes (TAEs), driven by neutral beam injection (NBI) hot ions, are described for the tokamak T-15 under construction in Kurchatov Institute to test a possible influence on and plasma particle losses. The baseline scenario with 10-s flat-top 2 MA current stage, 6-MW NBI plus 6 MW electron cyclotron resonance (ECR) heating is computed ASTRA code. spatial structure frequencies different TAE modes indexes n = 8 have been obtained ideal magnetohydrodynamic KINX...