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

B. S. Schmidt; M. Salewski; D. Moseev; M. Baquero-Ruiz; P. C. Hansen; J. Eriksson; O. Ford; G. Gorini; H. Järleblad; Ye O. Kazakov; D. Kulla; S. Lazerson; J. E. Mencke; D. Mykytchuk; M. Nocente; P. Poloskei; M. Rud; Antti Snicker; L. Stagner; S. Äkäslompolo; the W7-X Team

doi:10.1088/1741-4326/acd6a6

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

B. S. Schmidt^*, M. Salewski, D. Moseev, M. Baquero-Ruiz, P. C. Hansen, J. Eriksson, O. Ford, G. Gorini, H. Järleblad, Ye O. Kazakov, D. Kulla, S. Lazerson, J. E. Mencke, D. Mykytchuk, M. Nocente, P. Poloskei, M. Rud, Antti Snicker, L. Stagner, S. Äkäslompolothe W7-X Team

^*Corresponding author for this work

Not published at VTT

Research output: Contribution to journal › Article › Scientific › peer-review

19 Citations (Scopus)

Abstract

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.

Original language	English
Article number	076016
Journal	Nuclear Fusion
Volume	63
Issue number	7
DOIs	https://doi.org/10.1088/1741-4326/acd6a6
Publication status	Published - Jul 2023
MoE publication type	A1 Journal article-refereed

Funding

This work has been carried out within the framework of the EUROfusion Consortium, partially funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No. 101052200—EUROfusion). The Swiss contribution to this work has been funded by the Swiss State Secretariat for Education, Research and Innovation (SERI). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union, the European Commission or SERI. Neither the European Union nor the European Commission nor SERI can be held responsible for them. Further, the assistance provided by Friedemann Herold was greatly appreciated.

Keywords

fast ions
NBI
slowing-down
stellarator
Tokamak
tomography

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1088/1741-4326/acd6a6

Cite this

Schmidt, B. S., Salewski, M., Moseev, D., Baquero-Ruiz, M., Hansen, P. C., Eriksson, J., Ford, O., Gorini, G., Järleblad, H., Kazakov, Y. O., Kulla, D., Lazerson, S., Mencke, J. E., Mykytchuk, D., Nocente, M., Poloskei, P., Rud, M., Snicker, A., Stagner, L., ... the W7-X Team (2023). 4D and 5D phase-space tomography using slowing-down physics regularization. Nuclear Fusion, 63(7), Article 076016. https://doi.org/10.1088/1741-4326/acd6a6

@article{9d0d2ebb475f42d9be2e4b38391ffa75,

title = "4D and 5D phase-space tomography using slowing-down physics regularization",

abstract = "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.",

keywords = "fast ions, NBI, slowing-down, stellarator, Tokamak, tomography",

author = "Schmidt, {B. S.} and M. Salewski and D. Moseev and M. Baquero-Ruiz and Hansen, {P. C.} and J. Eriksson and O. Ford and G. Gorini and H. J{\"a}rleblad and Kazakov, {Ye O.} and D. Kulla and S. Lazerson and Mencke, {J. E.} and D. Mykytchuk and M. Nocente and P. Poloskei and M. Rud and Antti Snicker and L. Stagner and S. {\"A}k{\"a}slompolo and {the W7-X Team}",

note = "Funding Information: This work has been carried out within the framework of the EUROfusion Consortium, partially funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No. 101052200—EUROfusion). The Swiss contribution to this work has been funded by the Swiss State Secretariat for Education, Research and Innovation (SERI). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union, the European Commission or SERI. Neither the European Union nor the European Commission nor SERI can be held responsible for them. Further, the assistance provided by Friedemann Herold was greatly appreciated. Publisher Copyright: {\textcopyright} 2023 The Author(s). Published on behalf of IAEA by IOP Publishing Ltd.",

year = "2023",

month = jul,

doi = "10.1088/1741-4326/acd6a6",

language = "English",

volume = "63",

journal = "Nuclear Fusion",

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Schmidt, BS, Salewski, M, Moseev, D, Baquero-Ruiz, M, Hansen, PC, Eriksson, J, Ford, O, Gorini, G, Järleblad, H, Kazakov, YO, Kulla, D, Lazerson, S, Mencke, JE, Mykytchuk, D, Nocente, M, Poloskei, P, Rud, M, Snicker, A, Stagner, L, Äkäslompolo, S & the W7-X Team 2023, '4D and 5D phase-space tomography using slowing-down physics regularization', Nuclear Fusion, vol. 63, no. 7, 076016. https://doi.org/10.1088/1741-4326/acd6a6

TY - JOUR

T1 - 4D and 5D phase-space tomography using slowing-down physics regularization

AU - Schmidt, B. S.

AU - Salewski, M.

AU - Moseev, D.

AU - Baquero-Ruiz, M.

AU - Hansen, P. C.

AU - Eriksson, J.

AU - Ford, O.

AU - Gorini, G.

AU - Järleblad, H.

AU - Kazakov, Ye O.

AU - Kulla, D.

AU - Lazerson, S.

AU - Mencke, J. E.

AU - Mykytchuk, D.

AU - Nocente, M.

AU - Poloskei, P.

AU - Rud, M.

AU - Snicker, Antti

AU - Stagner, L.

AU - Äkäslompolo, S.

AU - the W7-X Team

N1 - Funding Information: This work has been carried out within the framework of the EUROfusion Consortium, partially funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No. 101052200—EUROfusion). The Swiss contribution to this work has been funded by the Swiss State Secretariat for Education, Research and Innovation (SERI). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union, the European Commission or SERI. Neither the European Union nor the European Commission nor SERI can be held responsible for them. Further, the assistance provided by Friedemann Herold was greatly appreciated. Publisher Copyright: © 2023 The Author(s). Published on behalf of IAEA by IOP Publishing Ltd.

PY - 2023/7

Y1 - 2023/7

N2 - 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.

AB - 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.

KW - fast ions

KW - NBI

KW - slowing-down

KW - stellarator

KW - Tokamak

KW - tomography

UR - http://www.scopus.com/inward/record.url?scp=85160753845&partnerID=8YFLogxK

U2 - 10.1088/1741-4326/acd6a6

DO - 10.1088/1741-4326/acd6a6

M3 - Article

AN - SCOPUS:85160753845

SN - 0029-5515

VL - 63

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 7

M1 - 076016

ER -

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

Abstract

Funding

Keywords

UN SDGs

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ECO-Fusion: Finnish Ecosystem for Industrial Fusion Technology

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

Abstract

Funding

Keywords

UN SDGs

Access to Document

Other files and links

Fingerprint

Projects

ECO-Fusion: Finnish Ecosystem for Industrial Fusion Technology

Cite this