169 results on '"Ghendrih, Philippe"'
Search Results
2. Transport barrier onset and edge turbulence shortfall in fusion plasmas
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Dif-Pradalier, Guilhem, Ghendrih, Philippe, Sarazin, Yanick, Camenen, Yann, Donnel, Peter, Garbet, Xavier, Grandgirard, Virginie, Munschy, Yann, Vermare, Laure, and Widmer, Fabien
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Physics - Plasma Physics - Abstract
Turbulent plasmas notably self-organize to higher energy states upon application of additional free energy sources or modification of edge operating conditions. Mechanisms whereby such bifurcations occur have been actively debated for decades. Enhanced confinement occurs at the plasma edge, where a shortfall of predicted turbulence intensity has been puzzling scientists for decades. We show, from the primitive kinetic equations that both problems are connected and that interplay of confined plasma turbulence with its material boundaries is essential to curing the shortfall of predicted turbulence and to triggering spontaneous transport barrier onset at the plasma edge. Both problems determine access to improved confinement and are central to fusion research. A comprehensive discussion of the underlying mechanisms is proposed. These results, highly relevant to the quest for magnetic fusion may also be generic to many problems in fluids and plasmas where turbulence self-advection is active.
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- 2022
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3. The 21N-moment multi-temperature coefficients for Zhdanov closure
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Raghunathan, Madhusudan, Marandet, Yannick, Bufferand, Hugo, Ciraolo, Guido, Ghendrih, Philippe, Tamain, Patrick, and Serre, Eric
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Physics - Plasma Physics - Abstract
We provide the 21N-moment multi-temperature collision coefficients for the Boltzmann collision operator using the Sonine-Hermite polynomial ansatz in the style of Zhdanov et al. First, we outline the general derivation method. Then, we provide the collision coefficients in the most general form in terms of the Chapman-Cowling integrals for any potential of interaction for the 21N-moment approximation. Then, we provide the the collision coefficients for the specific case of the approximated Coulomb potential cross-section with Debye cutoff. These coefficients help in order to find easy implementation in current SOL/edge fluid packages which currently implement the 21N-moment single-temperature coefficients. This provides the completion of a missing link in the current literature., Comment: 19 pages, 0 figures. Accepted by Contributions to Plasma Physics (Dec 2021). arXiv admin note: substantial text overlap with arXiv:2103.02455
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- 2021
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4. Multi-temperature Generalized Zhdanov Closure for Scrape-Off Layer/Edge Applications
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Raghunathan, Madhusudan, Marandet, Yannick, Bufferand, Hugo, Ciraolo, Guido, Ghendrih, Philippe, Tamain, Patrick, and Serre, Eric
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Physics - Plasma Physics - Abstract
The derivation of the multi-temperature generalized Zhdanov closure is provided starting from the most general form of the left hand side of the moment averaged kinetic equation with the Sonine-Hermite polynomial ansatz for an arbitrary number of moments. The process of arriving at the reduced higher-order moment equations, with its assumptions and approximations, is explicitly outlined. The generalized multi-species, multi-temperature coefficients from the authors' previous article are used to compute values of higher order moments such as heat flux in terms of the lower order moments. Transport coefficients and the friction and thermal forces for magnetic confinement fusion relevant cases with the generalized coefficients are compared to the scheme with the single-temperature coefficients previously provided by Zhdanov et al. It is found that the 21N-moment multi-temperature coefficients are adequate for most cases relevant to fusion. Furthermore, the 21N-moment scheme is also tested against the trace approximation to determine the range of validity of the trace approximation with respect to fusion relevant plasmas. Possible refinements to the closure scheme are illustrated as well, in order to account for quantities which might be significant in certain schemes such as the drift approximation., Comment: Submitted to Plasma Physics and Controlled Fusion, July 15, 2021
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- 2021
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5. Generalized Collisional Fluid Theory for Multi-Component, Multi-Temperature Plasma Using The Linearized Boltzmann Collision Operator for Scrape-Off Layer/Edge Applications
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Raghunathan, Madhusudan, Marandet, Yannick, Bufferand, Hugo, Ciraolo, Guido, Ghendrih, Philippe, Tamain, Patrick, and Serre, Eric
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Physics - Plasma Physics - Abstract
Grad's method is used on the linearized Boltzmann collision operator to derive the most general expressions for the collision coefficients for a multi-component, multi-temperature plasma up to rank-2. In doing so, the collision coefficients then get expressed as series sum of pure coefficients of temperature and mass ratios multiplied by the cross-section dependent Chapman-Cowling integrals. These collisional coefficients are compared to previously obtained coefficients by Zhdanov et al [Zhdanov V.M., Transport processes in multi-component plasma, Taylor and Francis (2002)] for 13N-moment multi-temperature scheme. First, the differences in coefficients are compared directly, and then the differences in first approximation to viscosity and friction force are compared. For the 13N-moment multi-temperature coefficients, it is found that they behave reasonably similarly for small temperature differences, but display substantial differences in the coefficients when the temperature differences are high, both for the coefficients and for viscosity and friction force values. Furthermore, the obtained coefficients are compared to the 21N-moment single-temperature approximation provided by Zhdanov et al, and it is seen that the differences are higher than the 13N-moment multi-temperature coefficients, and have substantial differences even in the vicinity of equal temperatures, especially for the viscosity and friction force calculations., Comment: Corrected some typos from the previous version. Accepted by Plasma Physics and Controlled Fusion (April 9,2021)
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- 2021
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6. Global fluid simulations of edge plasma turbulence in tokamaks: a review
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Schwander, Frédéric, Serre, Eric, Bufferand, Hugo, Ciraolo, Guido, and Ghendrih, Philippe
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- 2024
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7. Non-uniform splines for semi-Lagrangian kinetic simulations of the plasma sheath
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Bourne, Emily, Munschy, Yann, Grandgirard, Virginie, Mehrenberger, Michel, and Ghendrih, Philippe
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- 2023
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8. Verification and accuracy check of simulations with PoPe and iPoPe
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Cartier-Michaud, Thomas, Ghendrih, Philippe, Grandgirard, Virginie, and Serre, Eric
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- 2023
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9. Kinetic plasma-wall interaction using immersed boundary conditions
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Munschy, Yann, primary, Bourne, Emily, additional, Dif-Pradalier, Guilhem, additional, Donnel, Peter, additional, Ghendrih, Philippe, additional, Grandgirard, Virginie, additional, and Sarazin, Yanick, additional
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- 2024
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10. Author Correction: Transport barrier onset and edge turbulence shortfall in fusion plasmas
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Dif-Pradalier, Guilhem, Ghendrih, Philippe, Sarazin, Yanick, Caschera, Elisabetta, Clairet, Frédéric, Camenen, Yann, Donnel, Peter, Garbet, Xavier, Grandgirard, Virginie, Munschy, Yann, Vermare, Laure, and Widmer, Fabien
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- 2022
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11. Collisional relaxation and dynamical scaling in multiparticle collisions dynamics
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Lepri, Stefano, Bufferand, Hugo, Ciraolo, Guido, Di Cintio, Pierfrancesco, Ghendrih, Philippe, and Livi, Roberto
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Physics - Plasma Physics - Abstract
We present the Multi-Particle-Collision (MPC) dynamics approach to simulate properties of low-dimensional systems. In particular, we illustrate the method for a simple model: a one-dimensional gas of point particles interacting through stochastic collisions and admitting three conservation laws (density, momentum and energy). Motivated from problems in fusion plasma physics, we consider an energy-dependent collision rate that accounts for the lower collisionality of high-energy particles. We study two problems: (i) the collisional relaxation to equilibrium starting from an off-equilibrium state and (ii) the anomalous dynamical scaling of equilibrium time-dependent correlation functions. For problem (i), we demonstrate the existence of long-lived population of suprathermal particles that propagate ballistically over a quasi-thermalized background. For (ii) we compare simulations with the predictions of nonlinear fluctuating hydrodynamics for the structure factors of density fluctuations. Scaling analysis confirms the prediction that such model belong to the Kardar-Parisi-Zhang universality class., Comment: 12 pages, 4 figures. Accepted for publication in Proceedings of the IHP workshop "Numerical aspects of nonequilibrium dynamics", 25-27 April 2017 Paris, France, in "Proceedings in Mathematics and Statistics" (Springer)
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- 2018
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12. Fluid and kinetic modelling for non-local heat transport in magnetic fusion devices
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Ciraolo, Guido, Bufferand, Hugo, Di Cintio, Pierfrancesco, Ghendrih, Philippe, Lepri, Stefano, Livi, Roberto, Marandet, Yannick, Serre, Eric, Tamain, Patrick, and Valentinuzzi, Matteo
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Physics - Plasma Physics - Abstract
In order to improve the presently used ad hoc flux limiter treatment of parallel heat flux transport in edge plasma fluid codes we consider here a generalized version of the Fourier law implementing a non-local kernel for the heat flux computation. The Bohm boundary condition at the wall is recovered introducing a volumetric loss term representing the contribution of suprathermal particles to the energy out flux. As expected, this contribution is negligible in the strongly collisional regime while it becomes more and more dominant for marginally and low collisional regimes. In the second part of the paper, we consider a kinetic approach where collisions are considered using the Multi-Particle-Collision (MPC) algorithm. Kinetic simulation results at medium and low collisionality are also reported., Comment: 13 Pages, 6 figures, Accepted for publication in Contributions to Plasma Physics
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- 2018
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13. Kinetic plasma-sheath self-organization
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Munschy, Yann, primary, Bourne, Emily, additional, Dif-Pradalier, Guilhem, additional, Donnel, Peter, additional, Ghendrih, Philippe, additional, Grandgirard, Virginie, additional, and Sarazin, Yanick, additional
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- 2024
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14. Collisional Relaxation and Dynamical Scaling in Multiparticle Collisions Dynamics
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Lepri, Stefano, Bufferand, Hugo, Ciraolo, Guido, Di Cintio, Pierfrancesco, Ghendrih, Philippe, Livi, Roberto, Giacomin, Giambattista, editor, Olla, Stefano, editor, Saada, Ellen, editor, Spohn, Herbert, editor, and Stoltz, Gabriel, editor
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- 2019
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15. Beam-Plasma Instability and Fast Particles: the Lynden-Bell Approach
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Carlevaro, Nakia, Fanelli, Duccio, Garbet, Xavier, Ghendrih, Philippe, Montani, Giovanni, and Pettini, Marco
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Physics - Plasma Physics - Abstract
The beam-plasma instability, i.e. the response of the plasma bulk to the injection of supra thermal charged-particle beams, results to be appropriately characterized by a long-range interaction system. This physical system hosts a number of very interesting phenomena and, in particular, the emergence of long-lived quasi-stationary states. We characterize the self-consistent distribution functions of such out-of-equilibrium states by means of the Lynden-Bell's theory. The prediction of this theory, based on the statistical mechanics of the Vlasov equation, are checked against the outcomes of numerical simulations of the discrete system. Moreover, a phenomenological study of the effective resonance band for the system response is also addressed. A threshold value has been found in the initial spread of beam-particle momenta. This threshold allows to discriminate between the resonant and non-resonant regimes. The analysis of the thermalization of a few percents of the beam population characterized by large initial momenta (with respect to the main part of the beam itself) is also performed and it confirms and deepens the understanding of the physical meaning of the mentioned threshold., Comment: 21 pages, 14 figures
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- 2013
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16. Accuracy of unperturbed motion of particles in a gyrokinetic semi-Lagrangian code
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Latu, Guillaume, Grandgirard, Virginie, Abiteboul, Jérémie, Bergot, Morgane, Crouseilles, Nicolas, Garbet, Xavier, Ghendrih, Philippe, Mehrenberger, Michel, Sarazin, Yanick, Sellama, Hocine, Sonnendrücker, Eric, and Zarzoso, David
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Computer Science - Numerical Analysis ,Mathematics - Analysis of PDEs ,Mathematics - Numerical Analysis - Abstract
Inaccurate description of the equilibrium can yield to spurious effects in gyrokinetic turbulence simulations. Also, the Vlasov solver and time integration schemes impact the conservation of physical quantities, especially in long-term simulations. Equilibrium and Vlasov solver have to be tuned in order to preserve constant states (equilibrium) and to provide good conservation property along time (mass to begin with). Several illustrative simple test cases are given to show typical spurious effects that one can observes for poor settings. We explain why Forward Semi-Lagrangian scheme bring us some benefits. Some toroidal and cylindrical GYSELA runs are shown that use FSL., Comment: No. RR-8054 (2012)
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- 2012
17. Transport barrier for the radial diffusion due to the ExB drift motion of guiding centers in cylindrical confinement geometry
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Izacard, Olivier, Tronko, Natalia, Chandre, Cristel, Ciraolo, Guido, Vittot, Michel, and Ghendrih, Philippe
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Physics - Plasma Physics ,Nonlinear Sciences - Chaotic Dynamics - Abstract
We consider the radial transport of test particles due to the ExB drift motion in the guiding center approximation. Using an explicit expression to modify the electrostatic potential, we show that it is possible to construct a transport barrier which suppresses radial transport. We propose an algorithm for the implementation of this local modification computed from an electrostatic potential known on a spatio-temporal grid. The number of particles which escape the inner region defined by the barrier measures the efficiency of the control. We show that the control is robust by showing a significant reduction of radial transport, when applied with a reduced number of probes aligned on a circle., Comment: 13 pages, 9 figures, 1 column
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- 2010
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18. Derivation of a gyrokinetic model. Existence and uniqueness of specific stationary solutions
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Ghendrih, Philippe, Hauray, Maxime, and Nouri, Anne
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Mathematics - Analysis of PDEs - Abstract
A finite Larmor radius approximation is derived from the classical Vlasov equation, in the limit of large (and uniform) external magnetic field. We also provide an heuristic derivation of the electroneutrality equation in the finite Larmor radius setting. Existence and uniqueness of a solution is proven in the stationary frame for solutions depending only on the direction parallel to the magnetic field and factorizing in the velocity variables.
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- 2010
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19. Barriers for the reduction of transport due to the EXB drift in magnetized plasmas
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Tronko, Natalia, Vittot, Michel, Chandre, Cristel, Ghendrih, Philippe, and Ciraolo, Guido
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Mathematical Physics ,Mathematics - Dynamical Systems ,Nonlinear Sciences - Chaotic Dynamics - Abstract
We consider a 1 1/2degrees of freedom Hamiltonian dynamical system, which models the chaotic dynamics of charged test-particles in a turbulent electric field, across the confining magnetic field in controlled thermonuclear fusion devices. The external electric field E = \nabla\bigvee is modeled by a phenomenological potential V and the magnetic field B is considered uniform. It is shown that, by introducing a small additive control term to the external electric field, it is possible to create a transport barrier for this dynamical system. The robustness of this control method is also investigated. This theoretical study indicates that alternative transport barriers can be triggered without requiring a control action on the device scale as in present Internal Transport Barriers (ITB)., Comment: 18
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- 2009
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20. Control of test particle transport in a turbulent electrostatic model of the Scrape Off Layer
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Ciraolo, Guido, Ghendrih, Philippe, Sarazin, Yanick, Chandre, Cristel, Lima, Ricardo, Vittot, Michel, and Pettini, Marco
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Physics - Plasma Physics ,Mathematics - Dynamical Systems ,Nonlinear Sciences - Chaotic Dynamics - Abstract
The ${\bm E}\times{\bm B}$ drift motion of charged test particle dynamics in the Scrape Off Layer (SOL)is analyzed to investigate a transport control strategy based on Hamiltonian dynamics. We model SOL turbulence using a 2D non-linear fluid code based on interchange instability which was found to exhibit intermittent dynamics of the particle flux. The effect of a small and appropriate modification of the turbulent electric potential is studied with respect to the chaotic diffusion of test particle dynamics. Over a significant range in the magnitude of the turbulent electrostatic field, a three-fold reduction of the test particle diffusion coefficient is achieved.
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- 2007
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21. Reduction and approximation in gyrokinetics
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Ghendrih, Philippe, Lima, Ricardo, and Mendes, R. Vilela
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Physics - Plasma Physics ,Physics - Fluid Dynamics - Abstract
The gyrokinetics formulation of plasmas in strong magnetic fields aims at the elimination of the angle associated with the Larmor rotation of charged particles around the magnetic field lines. In a perturbative treatment or as a time-averaging procedure, gyrokinetics is in general an approximation to the true dynamics. Here we discuss the conditions under which gyrokinetics is either an approximation or an exact operation in the framework of reduction of dynamical systems with symmetry, Comment: 15 pages latex
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- 2007
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22. Control of stochasticity in magnetic field lines
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Chandre, Cristel, Vittot, Michel, Ciraolo, Guido, Ghendrih, Philippe, and Lima, Ricardo
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Nonlinear Sciences - Chaotic Dynamics - Abstract
We present a method of control which is able to create barriers to magnetic field line diffusion by a small modification of the magnetic perturbation. This method of control is based on a localized control of chaos in Hamiltonian systems. The aim is to modify the perturbation locally by a small control term which creates invariant tori acting as barriers to diffusion for Hamiltonian systems with two degrees of freedom. The location of the invariant torus is enforced in the vicinity of the chosen target. Given the importance of confinement in magnetic fusion devices, the method is applied to two examples with a loss of magnetic confinement. In the case of locked tearing modes, an invariant torus can be restored that aims at showing the current quench and therefore the generation of runaway electrons. In the second case, the method is applied to the control of stochastic boundaries allowing one to define a transport barrier within the stochastic boundary and therefore to monitor the volume of closed field lines.
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- 2005
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23. Tailoring Phase Space : A Way to Control Hamiltonian Transport
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Ciraolo, Guido, Chandre, Cristel, Lima, Ricardo, Vittot, Michel, Pettini, Marco, and Ghendrih, Philippe
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Nonlinear Sciences - Chaotic Dynamics - Abstract
We present a method to control transport in Hamiltonian systems. We provide an algorithm - based on a perturbation of the original Hamiltonian localized in phase space - to design small control terms that are able to create isolated barriers of transport without modifying other parts of phase space. We apply this method of localized control to a forced pendulum model and to a system describing the motion of charged particles in a model of turbulent electric field.
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- 2004
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24. Controlling chaotic transport in a Hamiltonian model of interest to magnetized plasmas
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Ciraolo, Guido, Chandre, Cristel, Lima, Ricardo, Vittot, Michel, Pettini, Marco, Figarella, Charles, and Ghendrih, Philippe
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Nonlinear Sciences - Chaotic Dynamics - Abstract
We present a technique to control chaos in Hamiltonian systems which are close to integrable. By adding a small and simple control term to the perturbation, the system becomes more regular than the original one. We apply this technique to a model that reproduces turbulent ExB drift and show numerically that the control is able to drastically reduce chaotic transport.
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- 2004
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25. Control of chaotic transport in Hamiltonian systems
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Ciraolo, Guido, Chandre, Cristel, Lima, Ricardo, Vittot, Michel, Pettini, Marco, Figarella, Charles, and Ghendrih, Philippe
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Nonlinear Sciences - Chaotic Dynamics ,Mathematical Physics ,Physics - Plasma Physics - Abstract
It is shown that a relevant control of Hamiltonian chaos is possible through suitable small perturbations whose form can be explicitly computed. In particular, it is possible to control (reduce) the chaotic diffusion in the phase space of a Hamiltonian system with 1.5 degrees of freedom which models the diffusion of charged test particles in a ``turbulent'' electric field across the confining magnetic field in controlled thermonuclear fusion devices. Though still far from practical applications, this result suggests that some strategy to control turbulent transport in magnetized plasmas, in particular tokamaks, is conceivable., Comment: Latex2e-Revtex, 4 pages, 6 figures
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- 2003
26. Kinetic plasma-sheath self-organization
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Munschy, Yann, Bourne, Emily, Dif-Pradalier, Guilhem, Donnel, Peter, Ghendrih, Philippe, Grandgirard, Virginie, Sarazin, Yanick, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and European Project: 824158,H2020-EU.1.4. - EXCELLENT SCIENCE - Research Infrastructures ,EoCoE-II(2019)
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Kinetic ,[PHYS]Physics [physics] ,Sheath ,simulation ,Plasma physics ,Plasma wall interaction - Abstract
The interaction between a plasma and a solid surface is studied in a (1D-1V) kinetic framework using a localized particle and convective energy source. Matching the quasineutral plasma region and sheath horizon is addressed in the fluid framework with a zero heat flux closure. It highlights non-polytropic nature of the physics of parallel transport. Shortfalls of this approach compared to a reference kinetic simulation, highlighting the importance of the heat flux, leads to addressing the sound velocity, non-collisional closure and higher moment closure. No gain in the predictive capability is obtained. The kinetic constraint at the sheath horizon is discussed and modified to account for conditions that are actually met in simulations, namely quasineutrality with a small but finite charge density. Analyzing the distribution functions shows that collisional transfer is mandatory to achieve steady-state self-organization on the open field lines.
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- 2023
27. Collisional Relaxation and Dynamical Scaling in Multiparticle Collisions Dynamics
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Lepri, Stefano, primary, Bufferand, Hugo, additional, Ciraolo, Guido, additional, Di Cintio, Pierfrancesco, additional, Ghendrih, Philippe, additional, and Livi, Roberto, additional
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- 2019
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28. Role of avalanche transport in competing drift wave and interchange turbulence
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Ghendrih, Philippe, primary, Dif-Pradalier, Guilhem, additional, Panico, Olivier, additional, Sarazin, Yanick, additional, Bufferand, Hugo, additional, Ciraolo, Guido, additional, Donnel, Peter, additional, Fedorczak, Nicolas, additional, Garbet, Xavier, additional, Grandgirard, Virginie, additional, Hennequin, Pascale, additional, Serre, Eric, additional, and Tamain, Patrick, additional
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- 2022
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29. Transport barrier onset and edge turbulence shortfall in fusion plasmas
- Author
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Dif-Pradalier, Guilhem, primary, Ghendrih, Philippe, additional, Sarazin, Yanick, additional, Caschera, Elisabetta, additional, Clairet, Frédéric, additional, Camenen, Yann, additional, Donnel, Peter, additional, Garbet, Xavier, additional, Grandgirard, Virginie, additional, Munschy, Yann, additional, Vermare, Laure, additional, and Widmer, Fabien, additional
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- 2022
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30. Role of avalanche transport in competing drift wave and interchange turbulence
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Ghendrih, Philippe, Dif-Pradalier, Guilhem, Panico, Olivier, Sarazin, Yanick, Bufferand, Hugo, Ciraolo, Guido, Donnel, Peter, Fedorczak, Nicolas, Garbet, Xavier, Grandgirard, Virginie, Hennequin, Pascale, Serre, Eric, Tamain, Patrick, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), École polytechnique (X), Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)
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History ,[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,Computer Science Applications ,Education - Abstract
We complete the 2D 2-fields turbulence model previously used with an interchange-like instability by slightly modifying the parallel loss terms to drive drift wave instabilities. We show that the instability driven by temperature fluctuations of the sheath losses is identical to that of the drift wave turbulence. The linear analysis is performed and used to select control parameters that yield identical maximum growth rates for the interchange alone and drift wave alone instability. Combining the two instabilities doubles the maximum growth rate. The non-linear simulations are used to analyse the SOL width. The simulations allow one to identify a low field side SOL region where interchange and drift wave are unstable and a high field side SOL region where only the drift wave is unstable. The SOL profiles appear exponential in the region close to the source but depart from a simple exponential fall-off in the far SOL. The low field side SOL width is found to be larger in the interchange alone case, slightly smaller when both instabilities are present and finally narrower when only the drift waves. For the high field side SOL, without interchange, the drift wave SOL width is observed to be identical to that on the low field side and larger than that when both instabilities at play. The Sherwood dimensionless parameter, ratio of convective particle flux divided by the diffusive particle flux, is used to compare the efficiency of turbulent transport. The profiles of the Sherwood parameter for time and flux surface averaged transport indicate that turbulent transport is dominant close to the separatrix but is less effective towards the far SOL. The Sherwood parameter evolution, determined with the flux-surface averaged transport, indicates that outward avalanche transport with corrugations governs the case with interchange only. When combining the two instabilities, outward avalanche transport is less pronounced and inward avalanche transport is observed, reducing the overall turbulent transport efficiency. The avalanche transport with drift waves only compared to interchange only is found to be inhibited.
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- 2022
31. Collisions in magnetised plasmas
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Ghendrih Philippe, Cartier-Michaud Thomas, Dif-Pradalier Guilhem, Esteve Damien, Garbet Xavier, Grandgirard Virginie, Latu Guillaume, Norscini Claudia, and Sarazin Yanick
- Subjects
Applied mathematics. Quantitative methods ,T57-57.97 ,Mathematics ,QA1-939 - Abstract
Approximations for closing the kinetic equation for the one particle distribution function are calculated by using propagators. These provide the formal structure of the collision term in the Landau approximation. The method allows one to investigate the effect of inhomogeneities at the Debye scale and to analyse magnetised collisions, when the Larmor radius is smaller than the Debye length. This method also allows one developing a simple renormalisation scheme to derive the Lenard-Balescu collision operator.
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- 2015
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32. Unraveling the competition/synergy between turbulence and 3D magnetic perturbations
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Varennes, Robin, Garbet, Xavier, Bourne, Emilie, Vermare, L., Sarazin, Yanick, Dif-Pradalier, Guilhem, Grandgirard, Virginie, Ghendrih, Philippe, Donnel, Peter, Peret, Mathieu, Obrejan, Kevin, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and icard, valerie
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[NLIN] Nonlinear Sciences [physics] ,[NLIN]Nonlinear Sciences [physics] - Abstract
International audience
- Published
- 2022
33. Interface transport barriers in magnetized plasmas
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Norscini, Claudia, primary, Cartier-Michaud, Thomas, additional, Dif-Pradalier, Guilhem, additional, Garbet, Xavier, additional, Ghendrih, Philippe, additional, Grandgirard, Virginie, additional, and Sarazin, Yanick, additional
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- 2022
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34. Comparison of different interpolation operators including nonlinear subdivision schemes in the simulation of particle trajectories
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Bensiali, Bouchra, Bodi, Kowsik, Ciraolo, Guido, Ghendrih, Philippe, and Liandrat, Jacques
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- 2013
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35. Simulation Verification with PoPe
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Ghendrih, Philippe, Cartier-Michaud, Thomas, Grandgirard, Virginie, Serre, Eric, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)
- Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph] ,[PHYS.PHYS.PHYS-FLU-DYN]Physics [physics]/Physics [physics]/Fluid Dynamics [physics.flu-dyn] ,[PHYS.PHYS.PHYS-CLASS-PH]Physics [physics]/Physics [physics]/Classical Physics [physics.class-ph] ,[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] ,[PHYS.COND.CM-SM]Physics [physics]/Condensed Matter [cond-mat]/Statistical Mechanics [cond-mat.stat-mech] - Abstract
We present the theoretical background of the PoPe and iPoPe verification scheme. The verification that is performed uses the output of actual simulations of production runs. With a small computing overhead it is possible to check that the problem that is solved numerically is consistent with the equations that are to be addressed. In fact, one shows that the numerical error determined by both procedures can be split into a part proportional to the existing operators of the equations, thus modifying their control parameters, completed by a residual error orthogonal to these operators. The accuracy of the numerical solution can be tested on the error as well as on the modification of the control parameters. To illustrate the method, the evolution equation of a simple mechanical system with two conjugate degrees of freedom is used as simulation test bed. Importantly, although dissipative, the trajectory equations evolve towards a chaotic attractor, a strange attractor, characterised by a positive Lyapunov exponent and therefore sensitivity to initial conditions. It is shown that the chaotic state cannot be verified with the standard Method of Manufactured Solution. We present different facets of the PoPe verification method applied to this test case. We show that the evaluation of the accuracy is case dependent for two reasons. First, the error that is generated depends on the values of the control parameter and not only on the numerical scheme. Second, the target accuracy will depend on the problem one wants to address. In a case characterised by bifurcations between different states, the accuracy is determined by the level of detail of the bifurcation phenomena one wants to achieve. A unique verification index is proposed to characterise the accuracy, and consequently the verification, of any given simulation in the production runs. This PoPe index then gives a level of confidence of each simulation. A PoPe index of zero characterises a situation with 100% error level. One finds that although the accuracy is poor the robust features of the solution can still be recovered. The maximum PoPe index is determined by machine precision, typically in the range of 12 to 14. As an illustration this PoPe index is used to choose between a high order integration scheme and a reduced order integration scheme that is less precise but requires less operations. For the chosen example the PoPe index indicates that the high order scheme leads to a reduction of computer resources up to a factor 4 at given accuracy.
- Published
- 2022
36. Verification and Accuracy Check of Simulations with Pope and Ipope
- Author
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Ghendrih, Philippe, primary
- Published
- 2022
- Full Text
- View/download PDF
37. Improving conservation properties of a 5D gyrokinetic semi-Lagrangian code
- Author
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Latu, Guillaume, Grandgirard, Virginie, Abiteboul, Jérémie, Crouseilles, Nicolas, Dif-Pradalier, Guilhem, Garbet, Xavier, Ghendrih, Philippe, Mehrenberger, Michel, Sarazin, Yanick, and Sonnendrücker, Eric
- Published
- 2014
- Full Text
- View/download PDF
38. Phase space structures in gyrokinetic simulations of fusion plasma turbulence
- Author
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Ghendrih, Philippe, Norscini, Claudia, Cartier-Michaud, Thomas, Dif-Pradalier, Guilhem, Abiteboul, Jérémie, Dong, Yue, Garbet, Xavier, Gürcan, Ozgür, Hennequin, Pascale, Grandgirard, Virginie, Latu, Guillaume, Morel, Pierre, Sarazin, Yanick, Storelli, Alexandre, and Vermare, Laure
- Published
- 2014
- Full Text
- View/download PDF
39. Transport in Fusion Plasmas: Is the Tail Wagging the Dog?
- Author
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Dif-Pradalier, Guilhem, primary, Ghendrih, Philippe, additional, Sarazin, Yanick, additional, Caschera, Elisabetta, additional, Clairet, Frederic, additional, Camenen, Yann, additional, Garbet, Xavier, additional, Grandgirard, Virginie, additional, Munschy, Yann, additional, Vermare, Laure, additional, and Widmer, Fabien, additional
- Published
- 2021
- Full Text
- View/download PDF
40. Fusion plasma turbulence described by modified sandpile dynamics
- Author
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Ghendrih, Philippe, Ciraolo, Guido, Dif-Pradalier, Guilhem, Norscini, Claudia, Sarazin, Yanick, Abiteboul, Jérémie, Cartier-Michaud, Thomas, Garbet, Xavier, Grandgirard, Virginie, and Strugarek, Antoine
- Published
- 2014
- Full Text
- View/download PDF
41. Color Figures
- Author
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Diamond, Patrick H., primary, Garbet, Xavier, additional, Ghendrih, Philippe, additional, and Sarazin, Yanick, additional
- Published
- 2015
- Full Text
- View/download PDF
42. Model order reduction approach to one-dimensional collisionless closure problem
- Author
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Gillot, Camille, Dif-Pradalier, Guilhem, Garbet, Xavier, Ghendrih, Philippe, Grandgirard, Virginie, Sarazin, Yanick, CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), and Sarazin, Yanick
- Subjects
[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,[PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] - Published
- 2021
43. model of interchange turbulent transport: on the correlation between scrape off layer width and core confinement in tokamaks
- Author
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Fedorczak, N., Peret, Mathieu, Ghendrih, Philippe, Tamain, Patrick, Bufferand, Hugo, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and icard, valerie
- Subjects
[PHYS]Physics [physics] ,[PHYS.PHYS]Physics [physics]/Physics [physics] ,Physics::Plasma Physics ,[PHYS.PHYS] Physics [physics]/Physics [physics] ,[PHYS] Physics [physics] - Abstract
International audience; Spectral filament paradigm: self consistent prediction of turbulent spectra (, Φ) of flux driven 2D isothermal interchange turbulence Predicts macroscopic transport properties (flux, fluctuations) in scrape-off layer ( SOL width) but also in the core ( confinement time) SOL transport: quantitative agreement with Tore Supra data (circular plasmas), recovers impact of divertor leg length on SOL width () in TCV, recovers multi-machine parametric sensitivity of Core confinement: recovers multi-machine parametric sensitivity of and correlation between core confinement and heat flux width Offers a flexible paradigm for addressing the optimization of power exhaust versus core confinement (key: impact of geometry in model) 2D isothermal interchange model (TOKAM2D)
- Published
- 2019
44. PoPe method for quantitative simulation verification of production runs
- Author
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Ghendrih, Philippe, Cartier-Michaud, Thomas, Ghendrih, Philippe, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
- Subjects
[INFO.INFO-PF]Computer Science [cs]/Performance [cs.PF] ,[NLIN.NLIN-AO] Nonlinear Sciences [physics]/Adaptation and Self-Organizing Systems [nlin.AO] ,[NLIN.NLIN-CD] Nonlinear Sciences [physics]/Chaotic Dynamics [nlin.CD] ,[INFO.INFO-PF] Computer Science [cs]/Performance [cs.PF] ,ACM: F.: Theory of Computation/F.2: ANALYSIS OF ALGORITHMS AND PROBLEM COMPLEXITY ,[SPI.PLASMA]Engineering Sciences [physics]/Plasmas ,[NLIN.NLIN-CD]Nonlinear Sciences [physics]/Chaotic Dynamics [nlin.CD] ,[SPI.PLASMA] Engineering Sciences [physics]/Plasmas ,[PHYS.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] ,[PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] ,[INFO.INFO-MO] Computer Science [cs]/Modeling and Simulation ,[NLIN.NLIN-AO]Nonlinear Sciences [physics]/Adaptation and Self-Organizing Systems [nlin.AO] ,[INFO.INFO-MO]Computer Science [cs]/Modeling and Simulation - Published
- 2017
45. Fluid description of neutral particles in divertor regimes in WEST
- Author
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Valentinuzzi, Matteo, Giorgiani, Giorgio, Marandet, Yannick, Bufferand, Hugo, Ciraolo, Guido, Ghendrih, Ph., Tamain, Patrick, Serre, Eric, Ghendrih, Philippe, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), ANR-10-EQPX-0029,EQUIP@MESO,Equipement d'excellence de calcul intensif de Mesocentres coordonnés - Tremplin vers le calcul petaflopique et l'exascale(2010), European Project: 633053,H2020,EURATOM-Adhoc-2014-20,EUROfusion(2014), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
hybrid model ,computational fluid dynamics ,Computational fluid dynamics ,Kinetic energy ,01 natural sciences ,010305 fluids & plasmas ,Physics::Fluid Dynamics ,models ,Discontinuous Galerkin method ,Physics::Plasma Physics ,0103 physical sciences ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,Kinetic Monte Carlo ,010306 general physics ,Physics ,Coupling ,business.industry ,Divertor ,Mechanics ,Plasma ,Solver ,Condensed Matter Physics ,flow ,discontinuous galerkin ,transport ,simulations ,business - Abstract
International audience; A new neutral fluid code has been developed as a necessary step towards a hybrid fluid/kinetic neutral model, to be used in ITER or DEMO simulations, where part of the divertor will be very collisional for neutrals. The neutral fluid code, which is able to handle complex geometries in view of the coupling to Soledge2D, is tested on plasma backgrounds obtained by Soledge2D‐Eirene in WEST geometry, for different divertor regimes, and is found to be in fair agreement with the kinetic Monte Carlo solver Eirene. The differences are due to the simplifications introduced in the fluid model and to the fact that a fluid description is not fully valid in these cases.
- Published
- 2018
46. Impact of self-consistent neutrals dynamics and particle sources on edge plasma transport and turbulence in 3D first principle simulations
- Author
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Tamain, Patrick, Baudoin, Camille, Bufferand, Hugo, Ciraolo, Guido, Fan, Dongmei, Fedorczak, Nicolas, Galassi, Davide, Ghendrih, Philippe, Luce, Benjamin, Marandet, Yannick, Nace, Nicolas, Serre, Eric, Schwander, Frédéric, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Physique des interactions ioniques et moléculaires (PIIM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Boutin, Olivier, and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[SPI.GPROC] Engineering Sciences [physics]/Chemical and Process Engineering ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2018
47. Effects of the electrostatic shear on the edge plasma in a two-field 휿−흐 like model implemented in the transport code SOLEDGE2D-EIRENE
- Author
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Baschetti, Serafina, Bufferand, Hugo, Ciraolo, Guido, Ghendrih, Philippe, Serre, Eric, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Boutin, Olivier, and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
[SPI.GPROC] Engineering Sciences [physics]/Chemical and Process Engineering ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,ComputingMilieux_MISCELLANEOUS - Abstract
International audience
- Published
- 2018
48. A multi-species collisional operator for full-F global gyrokinetics codes : Numerical aspects and validation with the GYSELA code
- Author
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Donnel, Peter, Garbet, Xavier, Sarazin, Yanick, Grandgirard, Virginie, Asahi, Yuuichi, Bouzat, Nicolas, Caschera, Elisabetta, Dif-Pradalier, Guilhem, Ehrlacher, Charles, Ghendrih, Philippe, Latu, Guillaume, Passeron, Chantal, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), TOkamaks and NUmerical Simulations (TONUS), Institut de Recherche Mathématique Avancée (IRMA), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Inria Nancy - Grand Est, and Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)
- Subjects
[PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph] ,multispecies ,[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,H-theorem ,neoclassic ,collision - Abstract
A linearized multi-species collision operator valid for arbitrary masses and charges has been developed and implemented in the gyrokinetic code GYSELA [9]. This operator has all the required properties : it conserves particles, total momentum and energy, fulfills the Boltzmann H theorem and recovers neoclassical results. This operator takes into account both pitch angle scattering and energy diffusion while operting in the v , µ phase space. Derivatives with respect to the magnetic moment are treated using a projection on a set of orthogonal polynomials. The numerical aspects of the implementation are detailed and a set of physical benchmarks allows a verification of the properties of the operator.
- Published
- 2018
49. Tokamak Edge Plasma Turbulence Interaction with Magnetic X-Point in 3D Global Simulations
- Author
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Galassi, Davide, primary, Ciraolo, Guido, additional, Tamain, Patrick, additional, Bufferand, Hugo, additional, Ghendrih, Philippe, additional, Nace, Nicolas, additional, and Serre, Eric, additional
- Published
- 2019
- Full Text
- View/download PDF
50. Drift-driven cross-field transport and Scrape-Off Layer width in the limit of low anomalous transport
- Author
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Baudoin, Camille, Tamain, Patrick, Bufferand, Hugo, Ciraolo, Guido, Fedorczak, Nicolas, Galassi, Davide, Gallo, Alberto, Ghendrih, Philippe, Nace, Nicolas, Institut de Recherche sur la Fusion par confinement Magnétique (IRFM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Modélisation et Simulation Numérique (en mécanique des fluides) (M2P2), Centre National de la Recherche Scientifique (CNRS)-Université de Provence - Aix-Marseille 1-Université Paul Cézanne - Aix-Marseille 3-Université de la Méditerranée - Aix-Marseille 2, Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Université de Provence - Aix-Marseille 1-Centre National de la Recherche Scientifique (CNRS), and Baudoin, Camille
- Subjects
[PHYS.PHYS.PHYS-PLASM-PH]Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] ,[PHYS.PHYS.PHYS-PLASM-PH] Physics [physics]/Physics [physics]/Plasma Physics [physics.plasm-ph] - Abstract
The impact of the ∇B-drift in the cross-field transport and its effect on the density and power scrape-off layer (SOL) width in the limit of low anomalous transport is studied with the fluid code SolEdge2D. In a first part of the work, the simulations are run with an isothermal reduced fluid model. It is found that a ∇B-drift dominated regime is reached in all geometries studied (JET-like, ASDEX-like and circular analytic geometries), and that the transition toward this regime comes along with the apparition of supersonic shocks, and a complex parallel equilibrium. The parametric dependencies of the SOL width in this regime are investigated, and the temperature and the poloidal magnetic field are found to be the principal parameters governing the evolution of the SOL width. In the second part of this paper, the impact of additional physics is studied (inclusion of the centrifugal drift, self-consistent variation of temperature and the treatment of the neutral species). The addition of centrifugal drift and neutral species are shown to play a role in the establishment of the parallel equilibrium, impacting the SOL's width. Finally, the numerical results are compared with the estimate of the Goldston's heuristic drift based model (HD-model), which has showed good agreement with experimental scaling laws. We find that the particles SOL's widths in the ∇B-drift dominated regime are, at least, two times smaller than the estimate of the HD-model. Moreover, in the parametric dependencies proposed by the HD-model, only the dependency with B pol is retrieved but not the one on T .
- Published
- 2017
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