Abstract Details
Abstracts
Author: Felix I Parra
Requested Type: Poster
Submitted: 2024-04-12 10:27:43
Co-authors: A. Geraldini, R.J. Ewart, M. Abazorius
Contact Info:
Princeton Plasma Physics Laboratory
100 Stellarator Road
Princeton, New Jersey 08540
United States
Abstract Text:
Controlling the energy flux to the wall of tokamaks and stellarators is crucial for magnetic confinement fusion energy. Since the width over which the exhausted power is spread depends on the turbulent cross-field transport, among other physics, there is an increasing interest in developing fluid, gyro-fluid and gyrokinetic codes that can describe that turbulence. The gyrokinetic and fluid descriptions are not valid in layers that form over the wall and have widths of the order of the Debye length (the Debye sheath), of the order of the gyro-radius (the magnetic presheath [1]) and of the order of the collisional mean-free-path (the collisional layer). These layers provide the boundary conditions for the gyrokinetic and fluid equations. Using the smallness of the angle between the magnetic field and the wall (first proposed as an expansion parameter in [2]), we have developed simplified models for these layers [3-5] that use minimal computational resources (the calculation takes a few minutes in one CPU, and it can be parallelized). With these models, we will show how these layers depend on parameters such as the electron-ion temperature ratio [6] and the angle between the magnetic field lines and the wall [7]. We will discuss what these layers imply for gyrokinetics and fluid models in the plasma edge.
References
[1] R. Chodura, Phys. Fluids 25, 1628 (1982).
[2] R.H. Cohen and D.D. Ryutov, Phys. Plasmas 5, 808 (1998).
[3] A. Geraldini et al, Plasma Phys. Control. Fusion 59, 025015 (2018).
[4] A. Geraldini et al, Plasma Phys. Control. Fusion 60, 125002 (2018).
[5] A. Geraldini, J. Plasma Phys. 85, 905870113 (2021).
[6] A. Geraldini et al, J. Plasma Phys. 85, 795850601 (2019).
[7] R.J. Ewart et al, Plasma Phys. Control. Fusion 64, 015010 (2022).
Comments:
Unfortunately, I have to be back in Princeton for the oral part of the doctoral general exam Thursday morning. For this reason, I will not be able to present my poster Wednesday afternoon.