Bindslev, H.

Garcia-Munoz, M.

Geiger, B.

Heidbrink, W.W.

Korsholm, Søren Bang

Leipold, Frank

Meo, Fernando

Michelsen, Poul

Moseev, D.

Nielsen, Stefan Kragh

Salewski, Mirko

Stejner, M.

Tardini, G.

Salewski, M.

Nielsen, S.

Heidbrink, W.

Korsholm, S.

Leipold, F.

Meo, F.

Michelsen, P.

MPG.PuRe

Tomography of 2D Velocity-space Distributions from Combined Synthetic Fast-ion Diagnostics at ASDEX Upgrade

Online Research Database In Technology

                       General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.  • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal   If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.     Downloaded from orbit.dtu.dk on: Dec 17, 2017Tomography of 2D Velocity-space Distributions from Combined Synthetic Fast-ionDiagnostics at ASDEX UpgradeSalewski, Mirko; Geiger, B.; Nielsen, Stefan Kragh; Bindslev, H.; Garcia-Munoz, M.; Heidbrink, W.W.;Korsholm, Søren Bang; Leipold, Frank; Meo, Fernando; Moseev, D.; Michelsen, Poul; Stejner, M.;Tardini, G.Published in:Programme &amp; Book of AbstractsPublication date:2012Document VersionPublisher's PDF, also known as Version of recordLink back to DTU OrbitCitation (APA):Salewski, M., Geiger, B., Nielsen, S. K., Bindslev, H., Garcia-Munoz, M., Heidbrink, W. W., ... Tardini, G. (2012).Tomography of 2D Velocity-space Distributions from Combined Synthetic Fast-ion Diagnostics at ASDEXUpgrade. In Programme & Book of Abstracts: 24th IAEA Fusion Energy Conference (pp. 315)TH–PSalewski Poster: Session P2, Tuesday 14:00 TH/P2–30Tomography of 2D Velocity-space Distributions fromCombined Synthetic Fast-ion Diagnostics at ASDEXUpgradeM. Salewski1, B. Geiger2, S. K. Nielsen1, H. Bindslev3, M. Garcia-Munoz2,W. W. Heidbrink4, S. B. Korsholm1, F. Leipold1, F. Meo1, D. Moseev2,5,P. Michelsen1, M. Stejner2, and G. Tardini21Technical University of Denmark, Roskilde, Denmark2Max-Planck-Institut fu¨r Plasmaphysik, Garching, Germany3Aarhus University, Aarhus, Denmark4University of California, Irvine, USA5FOM Institute DIFFER, EURATOM-FOM, Nieuwegein, NetherlandsCorresponding Author: msal@fysik.dtu.dkCollective Thomson scattering (CTS) and fast-ion Dα (FIDA) diagnostics measure 1D func-tions of the 2D fast-ion velocity distribution functions in magnetically confined plasmas. A singlesuch 1D measurement is usually not sufficient to build accurate tomographies of 2D anisotropicfast-ion velocity distribution functions. But we can compute tomographies from several simul-taneous 1D CTS and FIDA measurements. Such reconstructions contain salient features of theunderlying 2D fast-ion velocity distribution functions as was shown theoretically in 2004 fortwo and three synthetic 1D CTS measurements. Since then FIDA measurements have beendemonstrated, and several tokamaks have been equipped with multiple FIDA views. In 2012,a second CTS receiver and a second FIDA optical head have been installed on ASDEX Up-grade, so that four simultaneous 1D measurements of the 2D fast-ion distribution function arenow possible if CTS and FIDA measurements are used together. We reconstruct 2D fast-ionvelocity distribution functions from TRANSP/NUBEAM using combined synthetic 1D CTS andFIDA measurements. Here we develop a new reconstruction prescription that makes use of therecent idea of weight functions. In the past, reconstruction algorithms were made tractable byexpansion of the 1D (synthetic) measurements as well as the 2D fast-ion velocity distributionfunctions into orthonormal sets of base functions. Exploiting CTS or FIDA weight functionswe are lead to a simpler reconstruction prescription that is inherently tractable and obviatesthe use of such expansions. Our prescription is analogue to a tomography but in velocity spacerather than in configuration space. Computed tomography in configuration space is widely usedin medical imaging (X-ray, PET, MRI scanners) and also in nuclear fusion research. With ourprescription we can build tomographies of the 2D velocity distribution function for any set of 1Dfast-ion measurements obtained for any machine with multiple CTS or FIDA views or a mix ofthese. Applying our prescription to a set of real 1D fast-ion measurements will yield an entirelyexperimentally determined 2D fast-ion velocity distribution function that can be compared withsimulations.315

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Tomography of 2D Velocity-space Distributions from Combined Synthetic Fast-ion Diagnostics at ASDEX Upgrade

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