Speaker
Description
The theoretical and numerical modelling of fundamental kinetic processes in low collision plasmas is the oldest and most traditional research activity that the plasma theory team in Nancy began in the ‘60s, and which in the ‘80s led to the development of the first Eulerian and semi-Lagrangian Vlasov codes.
I will present a few of the recent research activities and results, carried out along this tradition and sometimes in collaboration with colleagues abroad, to which I took part. A key element is the inter-disciplinary character of this research activity whose applications span laser-plasma interactions, magnetically confined plasmas, space and astrophysical plasmas.
In particular, I will discuss some recent results exemplifying energy conversion processes that involve the formation and dissipation of coherent structures in low-collision turbulent plasmas, by highlighting the way they can be fundamentally connected in spite of their different frameworks of application:
the formation of transport barriers in gyrokinetic turbulence in tokamaks [1,2]; the shear-driven mechanism with which a turbulent plasma can be anisotropically heated via the so-called pressure-strain interaction and the limitations this imposes to a gyrokinetic modelling [3]; a recently identified kinetic heating that converts the magnetic energy produced by anisotropy-driven beam-plasma instabilities into kinetic energy, and which is different from magnetic reconnection [4]; and the dissipation of current sheets by magnetic reconnection in solar wind turbulence [5,6].
References:
[1] ““Ion temperature gradient mode mitigation by energetic particles, mediated by forced-driven zonal flows”, J. N. Sama, A. Biancalani, A. Bottino, D. Del Sarto, R. J. Dumont, G. Di Giannatale, A. Ghizzo , T. Hayward-Schneider, Ph. Lauber, B. McMillan, A. Mishchenko, M. Muruggapan, B. Rettino, B. Rofman, F. Vannini, L. Villard, X. Wang, , Phys. Plasmas 31, 112503 (2024).”
[2]“Emergence of E ×B staircase driven by the negative mass instability in tokamak plasmas”, A. Ghizzo, D. Del Sarto, to be submitted to Phys. Rev. E.
[3] “Violation of the gyrotropic pressure closure due to a velocity shear in a magnetized plasma”, D. Del Sarto, F. Pegoraro, 21eme Rencontre du Non Linéaire, p.7, (2018).
[4] “Collisionless heating driven by Vlasov filamentation in a counterstreaming beams configuration”, A. Ghizzo, D. Del Sarto, H. Betar, Phys. Rev. Lett. 131, 035101 (2023).
[5] “Plasma Turbulence in the Near-Sun and Near-Earth Solar Wind: A Comparison via Observation-Driven 2D Hybrid Simulations”, L. Franci, E. Papini, D. Del Sarto, P. Hellinger, D. Burgess, L. Matteini, S. Landi, V. Montagud-Camps, Universe 8, 453 (2022).
[6] “Microscopic current sheets and fast tearing modes in plasma turbulence”, H. Betar, D. Del Sarto, Astrophysical Journal, 990, 28 (2025).
