Abstract Details
Abstracts
Author: Alexey R Knyazev
Requested Type: Poster
Submitted: 2025-03-13 13:44:15
Co-authors: A. Lachmann, A. S. Hyder, E. J. Paul
Contact Info:
Columbia University
500 W 120th St
New York, New York 10027
USA
Abstract Text:
Recent advances in stellarator optimization [1,2] have achieved fusion power-plant relevant levels of fast particle confinement [3]. Further progress in equilibrium design necessitates assessment and minimization of particle losses from MHD waves present in these equilibria. For energetic ions, an important transport [4] mechanism is the resonant interaction of shear Alfvén waves with energetic ions [5,6]. Fast particle transport and their effects on MHD stability are currently under investigation using various fidelity models, including hybrid-kinetic [7] and recent quasi-linear [8] approaches.
In this work, we analyze shear Alfvén induced losses in recent quasi-symmetric equilibria using a minimal reduced incompressible ideal MHD vorticity [9] model. Our findings reveal that Alfvén eigenmodes localized in spectral gaps [10,11] can persist away from the edge in the presence of steep edge Alfvén speed shear and become the dominant prompt orbit loss driver beyond critical amplitude. By categorizing losses according to entrapment category, we determine that most wave-induced losses occur for particles undergoing class transitions. This developed analysis framework can serve for assessment of shear Alfvén wave induced losses in optimized stellarator configurations.
### References
1. Landreman and Paul, PRL, 2022
2. Goodman et al., PRX Energy, 2024
3. Bader et al., NF, 2021
4. Mynick, PoP 1993
5. Paul et al., JPP 2023
6. White and Duarte, PoP 2023
7. Varela et al., NF, 2019
8. Saby et al. NF 2025
9. Spong et al., PoP, 2003
10. Spong et al., PoP, 2010
11. Paul et al., JPP (submitted)
Characterization: 1.0
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