7 February 2024

Post-doctoral contract offer
To start before end of 2024

Subject : Electrostatic instabilities and transport in magnetizedfusion plasmas – theory and simulations
Informations générales
Workplace: Nancy, France (if absolutely necessary, remote work will be allowed for a few months)
Type of contract: Postdoctoral fixed-term contract, full-timeContract period: 24 months (an extension by one year is possible – funds are available)
Expected date of employment: Between March and December 2024 (ideally: September)Remuneration : Depending on experience, between 2597€ and 3246€ monthly before taxes
Typical monthly cost of life: About €400-500 for lodging, €300 food & misc.
Desired level of education: PhD
Experience required: -Subject description
To ensure the success of magnetic confinement thermonuclear fusion experiments such as ITER,
and to design a commercial fusion reactor, we need to overcome a number of remaining scientificchallenges. In particular, understanding and controlling instabilities and plasma turbulence is key inthe future of fusion energy. The target of current research is a robust predictability of characteristics(linear and non-linear) and the macroscopic impacts of turbulence (mainly transport, or turbulentmixing). Several paths can be explored, depending on the recruited person:
1. Modeling cylindrical plasmas.
Linear devices enable fundamental investigation of edge physics in a cylindrical geometry thatfacilitates modelisation, instrumentation, measurements, and interpretations. A new linear device,called SPEKTRE, is under construction in our laboratory. It is designed to approach the main
conditions encountered in the edge of fusion reactors such as ITER. A 2-minutes video presentationof SPEKTRE is available at http://bit.ly/ijl-spektre. It is a rather large device, the cylindrical vessel
being almost 1 meter in diameter, and more than 6 meters in length. The magnetic field will range
from 0.1 to possibly 0.9 T.
Conceptual drawing of theSPEKTRE device. The main
vacuum vessel, 6 m long and90 cm in diameter, houses aplasma confined by 13 copper
coils (in yellow).

Theoretical modelisation of SPEKTRE plasmas is an opportunity to test and improve the predictive
capabilities of existing models. It is also essential to prepare a toolbox of modelisation to be readyto exploit the future experiments. We will adopt a fluid and/or a gyrokinetic approach :- Two different electrostatic fluid codes can be used, a specific BOUT++ module and/or theNumerical Linear Device (NLD) code. An important objective is to treat adequately boundary
conditions (including sinks and sources of particles, energy, and momentum), and equilibrium
flows. In addition, it will be interesting to model impurities self-consistently.

-The gyrokinetic code GYSELA can be used in a cylindrical limit by taking a very large aspectratio. In this configuration, preliminary results show the presence of ITG and PVG instabilities.
Simulations can be used to explore the nonlinear coupling between these waves.

2. Role of fine-scale structures in both real-space AND velocity-space.
In hot plasmas, collisions are so rare that vortexlike fine scale structures develop in the phasespace of the particle distribution: coupling both real
space and velocity space. This is illustrated in thefigure, which show fluctuations of the distributionfunction in the (x,v) phase-space. Many PS vorticesof various sizes can form and interact, leading to a
new type of turbulence, which can be explored by
gyrokinetic simulations. More precisely, by isolating
one type of low-dimensional turbulence (dominatedby trapped-electron modes, TEM), as a fundamental prototype of more general turbulence, andtaking advantage of the reduced gyrokinetic numerical simulation code TERESA, phase-spacestructures can be investigated.

In summary, the mission for this postdoctoral work is to perform numerical simulations of hightemperature, magnetized plasmas, in cylindrical and/or toroidal geometry, and to analyse the results
based on linear, quasi-linear and non-linear theories, existing or to be developed. This work will
provide the building blocks towards a more comprehensive turbulence theory, with academic andsocioeconomic applications, not only in fusion energy, but in astrophysics, space weather, and space
exploration as well.

Work context
The post-doc will work within the “Fusion Plasmas” research group based in Nancy, under thesupervision of Dr. Maxime Lesur, in collaboration with the Institute for Magnetic Fusion Research in
CEA Cadarache, both LPP and CPHT in Polytechnique near Paris, the LPIIM in Marseille, the Centerfor Energy Research in UC San Diego, and the RIAM in Kyushu University, Japan. The work program
could include short stays in some of these laboratories.
This contract is funded by the Lorraine Université d’Excellence (LUE) initiative, and is part of one of
the 200 projects selected by Institut Universitaire de France.

About Institut Jean Lamour
The Institut Jean Lamour (IJL) is a joint research unit (UMR 7198) of CNRS and Université deLorraine. Focused on materials and processes science and engineering, it covers: materials,metallurgy, plasmas, surfaces, nanomaterials and electronics.
It regroups 183 researchers/lecturers, 91 engineers/technicians/administrative staff, 150 doctoral
students and 25 post-doctoral fellows. Partnerships exist with 150 companies and our researchgroups collaborate with more than 30 countries throughout the world.
Its exceptional instrumental platforms are spread over 4 sites; the main one is a new building locatedon Artem campus in Nancy.
In this large institute, the employees benefit from efficient administrative and technical services.

ApplicationApplicants are invited to send a résumé (free format) and cover letter to:
maxime.lesur@univ-lorraine.fr
if possible before March 15th, 2024.