The center for Theoretical Physics (CPHT) at Ecole Polytechnique gathers research scientists working in diverse domains of fundamental and applied Physics. The overall coherence is assured by the corpus of common, transposable, mathematical and numerical methods.
CPHT is a joint research unit of CNRS and Ecole Polytechnique, and has a partnership with the Collège de France. His director is Jean-René Chazottes, Senior Researcher at CNRS.
CPHT is on the campus of Ecole Polytechnique, buildings 5 and 6. The reception offices are located in building 6 , offices 06.1046 and 06.1045.
 

Postal Address :
CPHT 
Ecole Polytechnique 
91128 Palaiseau cedex 
France

Secretary phone number : 01 69 33 42 01 (from abroad: +33 169 334 201)

Write an email to someone at CPHT :  : firstname.lastname@polytechnique.edu

 

 

The CPHT Young Researchers Seminar will be held on Thursday 30th May at 2:30 PM  in Louis Michel conference room.

Anustup Mukherjee :The Electronic and Transport Properties of the series FexCo1-xS2 through First-Principles Calculations.

Aditya Hebbar : Fantastic bounds and where to find them: An invitation to bootstrap.

The seminar will be followed by a high tea.

 

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PhD Student

Resarch activities at CPHT: Theory of Plasmas

 

Address CPHT, Ecole Polytechnique, 91128 Palaiseau cedex, France
Phone number +33 (0) 11 69 33 42 94
Email firstname.lastname@polytechnique.edu  
Office Building 6, Office 06.1021

Thesis: Fluid and Kinetic macroscopic instabilities in a tokamak plasma
Advisors: Hinrich Lutjens

Research interests: plasma physics, MHD, gyrokinetic theory, numerical methods, simulations and modelling

Abstract:

The dynamics governing the macroscopic instabilities in a tokamak plasma depend on a wide range of space-time scales. A detailed description of the underlying physics requires an appropriate physical model. It must be more advanced than an extended fluid model, the latter being restricted to the study of MHD or bi/multi-fluid effects. Its generalization towards a totally kinetic description makes it possible to study new phenomena, such as wave-particle resonances or finite Larmor radius effects. These effects give access to new families of instabilities, prohibited in the more restricted model, or in a model with a simplified geometry.

The shape of the small section of the torus has indeed a significant influence on the resonant modes in the system. The presence of a singular magnetic surface at equilibrium, the consideration of resistive effects inside the tokamak wall or the presence of external poloidal coils that define the magnetic field at equilibrium directly influence the families of resonant modes that are allowed in the system.

The development of ever more complex models is also motivated by experimental observations, which demonstrate that a simple fluid model such as MHD does not make it possible to accurately describe the physics involved, and that it is necessary to tend towards a kinetic model. This evolution of the physical model is conditioned by the numerical method used and the HPC resources available. The purpose of it is to evolve in a state-of-the-art model from a physical and numerical point of view.

This thesis work is based on the 2-fluid/kinetic hybrid code XTOR-K developed at CPhT. In XTOR-K, the fluid dynamics of the electrons and of a given fraction of the ions of the thermalized background plasma are coupled in a self-consistent way with the dynamics of selected populations of kinetic ions, which makes it possible to address all nonlinearities of the problem. The kinetic ions are handled by a PIC 6D method, integrating exactly the trajectories along the cyclotron gyrations. Unfortunately, the latter method is very costly in computational resources. Thus, one of the goals of this thesis is to try and implement a gyrokinetic solver that would compete with the current kinetic one. Since a gyrokinetic model neglects any finite Larmor radius effect, such a solver would make it possible to significantly reduce the computational time needed for each simulation.

The current version of our XTOR-K code assumes that the boundary of the simulation domain is a perfectly conducting toroidal shell. However, a large number of instabilities are located close to this shell, and their dynamics is significantly impacted by this proximity. In order to free ourselves from this constraint, we have to continue our development effort allowing us to adopt more realistic boundary conditions, with ultimately a resistive shell and a set of poloidal magnetic coils allowing the control in time of the shape of the small plasma section as well as its vertical stability.

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Marc Henneaux donnera son cours au Collège de France  sur le "Formalisme des antichamps, cohomologie BRST et renormalisation des théories de jauge" les mercredis 15, 22, 29 mai et 5, 12, 19 juin 2024.

Plus d'informations : ici

Le cours sera suivi d'un colloque les 20 et 21 juin intégré dans l'Institut d'été de l'ENS.

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The CPHT Young Researchers Seminar will be held on Thursday 7th March at 15h00 in Louis Michel conference room.

Our two speakers are coming from outside our lab this time again !!

Victor Franken : Quantum Gravity as a discovery tool for QFT.

Frederick del Pozo : Revealing topology through light in topological superconductors.

The seminar will be followed by a high tea.

 

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Le CMAP, le CMLS et le CPHT organisent des journées thématiques dont l'audience visée est un large public de mathématicien-ne-s et de physicien-ne-s. La prochaine journée aura pour thème les processus de branchement, thème qui sera abordé sous différents points de vue par :

Nicolas Curien (LMO, université Paris-Saclay)
Igor Kortchemski (CMAP, CNRS, école polytechnique)
Apolline Louvet (Technische Universität München )
Alberto Rosso (CNRS, LPTMS, université Paris-Saclay)

Cette journée aura lieu le 25 janvier 2023 de 10h30 à 16h15.

Plus d'informations sont disponibles à l'adresse suivante :
https://indico.math.cnrs.fr/event/11306/ 

Pour des raisons logistiques, l'inscription est gratuite mais obligatoire. Elle s'effectue à l'adresse suivante :
https://indico.math.cnrs.fr/event/11306/registrations/1028/

En espérant vous y voir nombreux et nombreuses,
Pour l'organisation, Anne-Sophie de Suzzoni, Jean-René Chazottes, Anne de Bouard, Stéphane Munier

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David Rivera Betancour  will publicly defend his thesis work on Wednesday 6 of December at 15:00 hrs in room Louis Michel. 
Title: Aspects of Carrollian physics.
 
There will be also the possibility to attend via Zoom with following link:
 
Everyone is invited to attend the defense as well as the pot de thèse afterwards.
 
 
 

 

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Workshop Fluids, black holes, conformal systems and null infinity

December 8th, 2023,
11 am – 6 pm
Salle Louis-Michel CPHT, École polytechnique

Speakers :

11:00-11:30
Blaise Goutéraux (CPHT-École polytechnique, Palaiseau, FRANCE)
Thermodynamics, entropy production and linear dynamical stability

11:45-12:15
Tassos Petkou (Aristotle University, Thessaloniki, GREECE)
Thermal partition functions as conformal graphs

12:30-13:00
Xavier Bekaert (Institut Denis Poisson, Tours, FRANCE)
Carrollian conformal scalar as Minkowskian singleton

Break 13:15-14h30

14:30-15:00
Yannick Herfray (Institut Denis Poisson, Tours, FRANCE)
Super null infinity and its super cuts

15:15-15:45
Olivera Miskovic (Pontificia Universidad Catolica, Valparaiso, CHILE)
Symplectic structure of the light front of field theories

Break 16:00-16h30

16:30-17:00
Simon Pekar (CPHT-École polytechnique, Palaiseau, FRANCE)
Higher-spin symmetry in flat space and its unfolded dynamics

17:15-17:45
Christos Charmousis (IJCLab-UPSaclay, Orsay, FRANCE)
Black holes with primary hair

Rejoindre Zoom Réunion
https://ecolepolytechnique.zoom.us/j/81919853661?pwd=RWc4azd5eFJ4dkkrOVM0OVJIZmlTdz09
ID de réunion: 819 1985 3661
Code secret: 253460

Organizers: Marios Petropoulos, David Rivera-Betancour, Matthieu Vilatte

 

 

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