Abstract Details
| status: | file name: | submitted: | by: |
|---|---|---|---|
| approved | sherwood_2026_abstract_zocco.pdf | 2026-03-17 07:43:57 | Alessandro Zocco |
Abstracts
Author: Alessandro Zocco
Requested Type: Poster
Submitted: 2026-03-17 07:42:43
Co-authors: Eduardo Rodriguez, James Edmiston
Contact Info:
IPP Greifswald
Wendelsteinstrasse 1
Greifswald, 17491
Germany
Abstract Text:
Our understanding of the physics of trapped electrons [1] is mostly based on electrostatic results. These have been extremely important in the description of particle transport both in tokamaks and stellarators, and in the assessment of the properties of turbulence in optimised stellarators. However, the persistence of trapped-electron effects at finite $beta$ in gyrokinetic simulations, and the high-$beta$ requirements in a stellarator like Wendelstein 7-X to achieve good trapped-electron properties [8] (for the so-called max-J configurations ) put in doubt any electrostatic analysis.
Analytical studies of electromagnetic trapped electron instabilities are extremely rare in the literature .
It is clear that while high-order corrections in a perturbative expansion for small magnetic drifts are necessary to reproduce ideal MHD results, it is not obvious to predict: i) what is the electromagnetic trapped-electrons resonant contribution when no fluid (non-resonant) effect can provide destabilization, like for the regular strongly-driven kinetic ballooning mode and/or ideal ballooning modes ii) what are the actual constraints on the plasma pressure that determine the validity of the TCH trapped-electrons-modified KBM equation, iii) how do electrons participate to the interchange physical mechanism that drives kinetic ballooning modes unstable, iv) what is the impact of the symmetries of magnetic curvature, for different families on confining devices, in relation to the destabilisation of finite$-beta$ trapped-electron modes. In this work, we address these problems. Refs. Rosenbluth Sloan 971 Phys. Fluids 14, Tang W, Connor J and Hastie R 1980 Nucl. Fusion 20 1439, Zocco Rodriguez and Edmiston, JPP, to appear, (2026)
Characterization: 1.0
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