4D and 5D phase-space tomography using slowing-down physics regularization

Nuclear Fushion

article

B.S. Schmidt¹  M. Salewski¹  D. Moseev²  M. Baquero-Ruiz³  P.C. Hansen⁴  J. Eriksson⁵  O. Ford²  G. Gorini⁶  H. Järleblad¹  Ye O. Kazakov⁷  D. Kulla²  S. Lazerson²  J.E. Mencke³  D. Mykytchuk³  M. Nocente⁶  P. Poloskei²  M. Rud¹  A. Snicker⁹  L. Stagner^1,10  S. Äkäslompolo² 

[1] Department of Physics, Technical University of Denmark;Max-Planck-Institut für Plasmaphysik;École Polytechnique Fédérale de Lausanne, Swiss Plasma Center;Department of Applied Mathematics and Computer Science, Technical University of Denmark;Department of Physics and Astronomy, Uppsala University;Dipartimento di Fisica, Università degli Studi di Milano-Bicocca;Laboratory for Plasma Physics;Institute for Plasma Science and Technology, National Research Council;Department of Applied Physics, Aalto University;General Atomics

关键词: fast ions;    tomography;    slowing-down;    NBI;    Tokamak;    stellarator;   

DOI  :  10.1088/1741-4326/acd6a6

来源: Institute of Physics Publishing Ltd.

【 摘 要 】

We compute reconstructions of 4D and 5D fast-ion phase-space distribution functions in fusion plasmas from synthetic projections of these functions. The fast-ion phase-space distribution functions originating from neutral beam injection (NBI) at TCV and Wendelstein 7-X (W7-X) at full, half, and one-third injection energies can be distinguished and particle densities of each component inferred based on 20 synthetic spectra of projected velocities at TCV and 680 at W7-X. Further, we demonstrate that an expansion into a basis of slowing-down distribution functions is equivalent to regularization using slowing-down physics as prior information. Using this technique in a Tikhonov formulation, we infer the particle density fractions for each NBI energy for each NBI beam from synthetic measurements, resulting in six unknowns at TCV and 24 unknowns at W7-X. Additionally, we show that installing 40 LOS in each of 17 ports at W7-X, providing full beam coverage and almost full angle coverage, produces the highest quality reconstructions.

【 授权许可】

Unknown