View in EDS

A zero order study of the effect of resonances on fast ions measured by FILD in ASDEX Upgrade.

Saved in:
Bibliographic Details
Title: A zero order study of the effect of resonances on fast ions measured by FILD in ASDEX Upgrade.
Authors: Zestanakis, P A1 (AUTHOR) panosz@central.ntua.gr, Anastassiou, G1 (AUTHOR), Rueda-Rueda, J2 (AUTHOR), Galdon-Quiroga, J3 (AUTHOR), Kominis, Y1 (AUTHOR), Upgrade Team, the ASDEX1 (AUTHOR), Tokamak Exploitation Team, the EUROfusion1 (AUTHOR)
Source: Plasma Physics & Controlled Fusion. Nov2025, Vol. 67 Issue 11, p1-18. 18p.
Subjects: Fast ions, Phase space, Plasma waves, Magnetohydrodynamics, Detectors, Magnetohydrodynamic instabilities, Tokamaks
Abstract: This work introduces the resonance index (RI) technique, a new methodology for exploring magnetohydrodynamic induced fast ion (FI) losses in tokamaks, with applications to cases involving toroidicity induced Alfvén eigenmodes and neoclassical tearing modes in ASDEX Upgrade. The RI technique focuses on the impact of the FI phase space topology on the mechanisms that drive FI loses and aims at the interpretation of signals from the FI loss detector (FILD). A fresh approach to orbit labeling is presented, linking the FI phase space with the FILD plane. Key findings, such as notable changes in RI and a distinct maximum along the boundary dividing phase space regions emphasize the importance of phase space topology in resonant interactions. As a deliberately zero-order model, RI retains only the axisymmetric guiding-center motion, assumes the toroidal canonical momentum to be effectively invariant, and folds the unknown mode structure into a single width parameter. These simplifications sacrifice quantitative accuracy for speed and transparency, making RI a qualitative—but rapid—tool for interpreting FILD patterns with surprising success in reproducing experimental findings. [ABSTRACT FROM AUTHOR]
Copyright of Plasma Physics & Controlled Fusion is the property of IOP Publishing and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:This work introduces the resonance index (RI) technique, a new methodology for exploring magnetohydrodynamic induced fast ion (FI) losses in tokamaks, with applications to cases involving toroidicity induced Alfvén eigenmodes and neoclassical tearing modes in ASDEX Upgrade. The RI technique focuses on the impact of the FI phase space topology on the mechanisms that drive FI loses and aims at the interpretation of signals from the FI loss detector (FILD). A fresh approach to orbit labeling is presented, linking the FI phase space with the FILD plane. Key findings, such as notable changes in RI and a distinct maximum along the boundary dividing phase space regions emphasize the importance of phase space topology in resonant interactions. As a deliberately zero-order model, RI retains only the axisymmetric guiding-center motion, assumes the toroidal canonical momentum to be effectively invariant, and folds the unknown mode structure into a single width parameter. These simplifications sacrifice quantitative accuracy for speed and transparency, making RI a qualitative—but rapid—tool for interpreting FILD patterns with surprising success in reproducing experimental findings. [ABSTRACT FROM AUTHOR]
ISSN:07413335
DOI:10.1088/1361-6587/ae105c