integrated data analysis of fast-ion measurements by ... · add presentation title in footer via...
TRANSCRIPT
Integrated data analysis of fast-ion measurements by velocity-space tomography
Mirko Salewski Technical University of Denmark
Department of Physics
M.Nocente, B.Geiger, A.S.Jacobsen, F.Binda, C.Cazzaniga, G. Gorini, G.Ericsson, J.Eriksson, W.W. Heidbrink, C.Hellesen, A.Hjalmarsson, V.G.Kiptily, S.B.Korsholm, T.Koskela, T.Kurki-Suonio, F.Leipold, J.Madsen, D.Moseev, S.K.Nielsen, J.Rasmussen, L.Stagner, M.Schneider, S.E.Sharapov, M.Stejner, M.Tardocchi, M.Weiland
2nd IAEA TM on Fusion Data Processing, Validation and Analysis 30 May - 2 June 2017, Cambridge, MA, USA
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
• Introduction to velocity-space tomography
• GRS/NES-based velocity-space tomography at JET
• FIDA-based velocity-space tomography at ASDEX Upgrade
• Summary and outlook
2
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Outline
Mirko Salewski
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
3
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Introduction to velocity-space tomography
Mirko Salewski
Forward problem
Salewski et al (2011,12,13,14,15,16,17) NF
Inverse problem
𝑊𝐹 = 𝑆
Distribution function F Measurements S Matrix W
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
• Introduction to velocity-space tomography
• GRS/NES-based velocity-space tomography at JET
• FIDA-based velocity-space tomography at ASDEX Upgrade
• Summary and outlook
4
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Outline
Mirko Salewski
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Neutron emission and gamma-ray spectrometry at JET
5 Mirko Salewski
Perpendicular view
Φ=90°(LOS, B)
Oblique view Φ=47°(LOS, B)
Eriksson et al (2015) NF
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
NES measurements
• 3 simultaneously measured spectra in JET #86459
• 4.5 MW NBI + 3 MW 3rd harmonic ICRF-heating
• Yellow: Used for inversion
6 Salewski et al (2017) NF
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
GRS measurements
• 2 GRS spectra in JET #86459
• High-resolution High-purity Germanium detector (1keV over 10 MeV)
• Two competing reactions
7 Salewski et al (2017) NF
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Velocity-space observation regions
• Weight functions w:
• Signal/ion
• Discretize:
• Reject data if w is
1) is outside the target velocity space.
2) covers the velocity space below 120 keV.
8
Jacobsen et al (2014) RSI, Jacobsen et al (2015) NF
Heidbrink et al (2007) PPCF
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Velocity-space observation regions
• 5 detectors
• 3 typical Doppler shifts
9
GRS 2868 keV
TOFOR
GRS 3367 keV
Diamond
NE213
High Medium Low
NES: Jacobsen et al (2014) RSI, Jacobsen et al (2015) NF
GRS: Salewski et al (2015) NF, Salewski et al (2016a) NF
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
10
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Inversion by 1st-order Tikhonov regularization
Mirko Salewski
• Forward problem:
• Inverse problem:
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Velocity-space tomography vs. simulation
• Basic features agree: Tail length, tail width.
• Barrier region suggests low densities above 2 MeV.
• Velocity-space tomography confirms the barrier experimentally.
11 Mirko Salewski
[a.u.] [a.u.] [a.u.]
Salewski et al (2017) NF
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
What if we only use NES or GRS?
12 Mirko Salewski
• Inversions rely on integrated data analysis
• NES only or GRS only do not work well
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
• Introduction to velocity-space tomography
• GRS/NES-based velocity-space tomography at JET
• FIDA-based velocity-space tomography at ASDEX Upgrade
• Summary and outlook
13
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Outline
Mirko Salewski
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
14
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
FIDA spectroscopy at ASDEX Upgrade
Weiland et al (2016) PPCF
Mirko Salewski
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
15
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Prior information: What do we know?
• F is non-negative.
• Null-measurements of FIDA light • (E,p) position of NBI peaks at E, E/2, E/3
Mirko Salewski Salewski et al (2016b) NF
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
16
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
High-definition tomography: Inversion using prior information
Simulation
Without prior information
With prior information
Artifacts
No visible artifacts
Mirko Salewski
Salewski et al (2016b) NF
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
17
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Tomography movie of a sawtooth crash
Salewski et al (2016b) NF
• Upper panel: Measurement of fast ion density
𝑛𝑓 = 𝑓𝑑𝐸𝑑𝑝
• Lower panel: tomographic inversion movie
• fit to 50.000 data points
–100 frames
–5 spectra per frame
–100 data points per spectrum
Mirko Salewski
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
18
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Sawteeth: FIDA tomography vs. TRANSP
TRANSP
FIDA
• Fairly good agreement
• Measured crashes smaller than simulated crashes.
• No measured crashes for |p|<0.25 in agreement with Kolesnichenko (1996) NF and disagreement with TRANSP.
Mirko Salewski
Salewski et al (2016b) NF
AUG #32323
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
19
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
For two-view FIDA systems: Numeric simulation as prior information
Salewski et al (2016b) NF
MUCH easier!
Not using TRANSP as prior information
Using TRANSP as prior information
Mirko Salewski
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
20
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Reconstruction of differences from TRANSP
• Cases with and without TRANSP as prior information give consistent results for the 5-view case.
• Works for 2 FIDA views.
Mirko Salewski Salewski et al (2016b) NF
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Optimal experimental design for fast-ion diagnostic sets
21 Mirko Salewski
• ASDEX Upgrade went from 3 to 5 FIDA views.
• Chose 2 viewing angles to best complement the other 3.
• Minimize quality parameter
• 85°and 50°are best.
Weiland et al (2016) PPCF
3 existing viewing angles
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Velocity-space observation regions
CTS
FIDA
NES
2-step GRS
1-step GRS
NPA: Heidbrink et al (2007) PPCF
CTS: Salewski et al (2011) NF
FIDA: Salewski et al (2014) PPCF
NES: Jacobsen et al (2015) NF
GRS-2: Salewski et al (2015) NF
GRS-1: Salewski et al (2016) NF
• W has vastly different forms for the different diagnostics.
• Known already.
22 Mirko Salewski
DTU Physics, Technical University of Denmark
Add Presentation Title in Footer via ”Insert”; ”Header & Footer”
Summary
23
• Velocity-space tomography reveals new physics.
– Converts complex data to straightforward 2D images
– Combines diagnostics
– Accounts for nuisance parameters
• MeV range ion velocity-space tomography based on 5 NES/GRS spectra agrees well with simulations
• FIDA-based velocity-space movies at ASDEX Upgrade
• Velocity-space studies of sawtooth crashes confirm pitch selectivity
• Increase fast-ion measurement data at AUG and JET
• Use thermal ion signals
• Demonstrate approach on other machines
• Apply: Alfven modes, NTM, sawteeth, burning plasma
• Improve inversion methods
• Go 3D (spatial coordinate, constants-of-motion or EPmRm) Stagner (this conference)
Mirko Salewski
Outlook
Thank you for your attention!