Postdoc position on the development and implementation of efficient meshing strategies based on hybrid discontinuous Galerkin method for plasma simulations in WEST and ITER (co-funded by Amidex)

RESEARCHER PROFILE: Postdoc / R2: PhD holders 
RESEARCH FIELD(S) AND DISCIPLINES1: Computational science – Physical science

JOB /OFFER DESCRIPTION 
Fusion based on magnetic confinement aims at producing power by using the energy liberated by fusing deuterium and tritium nuclei at extremely high temperatures (107-108K), within a plasma confined by magnetic fields in machines of toroidal shape known as tokamaks. ITER (https://www.iter.org/), which was designed as the key experimental step between today's research machines and tomorrow's fusion power plants, is certainly among the most ambitious technological and scientific challenges that humanity has set itself in recent years. 

The success of ITER will require reliable and efficient numerical tools to perform tokamak relevant simulations. The Hybrid Discontinuous Galerkin (HDG) method, which allows a magnetic equilibrium free approach by using high-order finite elements, has already shown very promising and original results with a strong potential for development to target the objectives to be reached by simulations to ensure a successful ITER operation. Indeed, target plasma simulations in ITER relevant conditions strongly strains current codes and requires improving their performance and reliability.

In recent years, the team has successfully developed the state-of-the-art transport code SOLEDGE-HDG to investigate turbulent transport in realistic 2D tokamak geometries [Giorgiani et al., 2018; Scotto et al. 2021]. In particular, the code is the first to allow the simulation of a full plasma discharge, including transient phases such as the ramp--up and shutdown, which are critical for the study of the overall performance of the machine. To push forward the capability of the HDG solver, and in particular to move to 3D transport simulations, we propose in this project to work on efficient meshing strategies based on triangles and quadrangles in 2D, and to their extension to 3D. The notion of optimal mesh with anisotropic flows such as in tokamak is very closely linked to the compatibility between the anisotropy of the mesh and that of the target flow.

In this context, a one-year renewable postdoctoral position is opened at the M2P2 laboratory in Marseille (Aix-Marseille Univ, CNRS, Ecole Centrale) to focus on meshing strategy able to optimize computations by differencing the mesh features between the core (close magnetic field lines) and the edge (around the separatrix and to the tokamak wall) in order to deal with the strong anisotropy of the plasma flow and the complex wall and plasma equilibrium geometries. Two strategies will be mainly investigated related to the alignment/misalignment of the mesh and its structured/unstructured nature.

WHAT WE OFFER 
This post-doc fellowship is part of the SAPHIR project funded by the Initiative d’excellence of Aix-Marseille Université AMIDEX to support the development of efficient simulation tools of flows in tokamak relevant configurations.  The project is co-supervised by two laboratories, M2P2 and I2M, co-accredited by Aix-Marseille University-CNRS-Ecole Centrale Méditerranée. M2P2 associates skills in numerical modelling, coding and plasma physics, and hosts the last generation of the French edge plasma codes in conjunction with IRFM-CEA. I2M Lab, the institute of Mathematics of Marseille, is in charge of numerical analysis and scientific computing issues raised by the system at hand.

Supervision of the research work will be assured by Eric Serre (M2P2 Lab), Frederic Schwander (M2P2 Lab) and Michel Mehrenberger (I2M Lab). 

Net monthly salary of €2,365.52 to €2,589.68 depending on experience

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TYPE OF CONTRACT: TEMPORARY / JOB STATUS: FULL TIME / HOURS PER WEEK: 37
JOB NOT FUNDED THROUGH AN EU RESEARCH FRAMEWORK PROGRAMME
APPLICATION DEADLINE: 1/04/2023 to 01/06/2023
ENVISAGED STARTING DATE:  1/04/2023 to 01/06/2023
ENVISAGED DURATION: 12 months renewable 
WORK LOCATION(S): M2P2 Lab, UMR7340, Ecole Centrale Marseille, 38 rue Joliot-Curie 13451 Marseille, France

QUALIFICATIONS, REQUIRED EDUCATION LEVEL, PROFESSIONAL SKILLS, RESEARCH REQUIREMENTS 
The candidate will hold a PhD in mathematics, physics or computer science, with a solid background in numerical modelling and coding. Competences in numerical analysis and plasma physics will be also appreciated. 

SOFT SKILLS
The numerical developments required will involve team-working skills to interact frequently with other post-docs/PhD working on the same numerical code. 

REQUESTED DOCUMENTS OF APPLICATION, SELECTION PROCESS

• A detailed CV
• A cover letter

WHERE TO APPLY: Please send full application to: eric.serre@univ-amu.fr