Speaker
Description
Accurately characterizing fast-ion distributions in fusion plasmas is crucial for understanding and controlling alpha heating and instabilities in future reactors. This work presents a significant advancement in fast-ion tomography by introducing a novel technique that not only reconstructs fast-ion distributions but also identifies the specific transport mechanisms responsible for shaping them.
This capability is achieved by extending the conventional slowing-down basis[1][2] with a set of transport basis functions, enabling the accurate reconstruction of fast-ion distributions even in the presence of complex transport dynamics. To validate this approach, we utilize synthetic fast-ion distributions generated by TRANSP and validated against experimental data from MAST-U.
Furthermore, we advance tomographic inversion techniques by integrating data from multiple[3] diagnostics on MAST-U, including FIDA, Neutron Collimation system, and solid state NPA. To overcome the limitations of individual diagnostics, we combine these measurements in velocity space and compare Bayesian multi-diagnostic techniques with more direct multi-parameter techniques. We also recast the multi-diagnostic problem in orbit space coordinates[4], demonstrating that diagnostics may not need overlapping real-space volumes to provide a comprehensive picture of the fast-ion distribution function.
[1] B Madsen et al 2020 Plasma Phys. Control. Fusion 62 115019
[2] B.S. Schmidt et al 2023 Nucl. Fusion 63 076016
[3] M. Salewski et al 2013 Nucl. Fusion 53 063019
[4] L Stagner et al 2017 Physics of Plasmas 24 092505
Works supported at UCI by DOE No. DE-SC0019253 and DE-FG02-06ER54867
| Presentation type | Oral |
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