Development of an experimental profile database for the scrape-off layer

Development of an experimental profile database for the scrape-off layer M. Groth, 1 G.D. Porter, 1 W.M. Meyer, 1 A.W. Leonard, 2 T.H. Osborne, 2 D.P. Coster, 3 A. Kallenbach, 3 M. Wischmeier 3 N.H. Brooks, 2 J. Harhausen, 3 H.W. Müller, 3 J.G. Watkins 4 And the ASDEX Upgrade and DIII-D teams 1 Lawrence Livermore National Laboratory, Livermore, CA, USA 2 General Atomics, San Diego, CA, USA 3 Institute for Plasma Physics, Garching, Germany 4 Sandia National Laboratory, Albuquerque, NM, USA Presented at the 9 th ITPA Divertor and SOL working group meeting Garching, Germany May 7-10, 2007

The.DIV branch of the ITPA Pedestal Profile Database pursues the same goals as its parent Create repository for blessed SOL data Facilitate cross-machine comparison of SOL profiles Provide data for SOL modeling and its validation Promote collaboration between existing devices, e.g., pedestal fueling experiments Format: MDSplus-based data structure MDSplus trees MDSplus commands, e.g., data=mdsvalue( MDSplus tag ) Database tree locations: AUGDIV (and AUGPED) at IPP Garching PED_D3D at General Atomics 2

Current status of data in the.div branch Available shots AUGDIV: e.g., divertor characterization: Ohmic density scan, H-mode PED_D3D: H-mode (JET/DIII-D similarity experiment) L-mode density scan (AUG/DIII-D fueling study) Available data (= data + geometry) Upstream profiles for n e, T e, T i, f Z (data and mtanh fits) Radiation profiles from bolometry Divertor profiles of j sat, n e, T e, P target, brightness at various emission lines Sets of independent coordinates: Ψ N, R-R sep,omp, and ds sep,target 3

PED_D3D tree structure contains both pedestal and SOL data Top-level branches for equilibrium, pedestal, and divertor data 4

PED_D3D tree structure contains both pedestal and SOL data Top-level branches for equilibrium, pedestal, and divertor data.div branch with 0-D, 1-D, and 2- D branches; time-averaged and time-resolved (for ELMs) 5

PED_D3D tree structure contains both pedestal and SOL data Top-level branches for equilibrium, pedestal, and divertor data.div branch with 0-D, 1-D, and 2- D branches; time-averaged and time-resolved (for ELMs).TWOD branch contains profile data, e.g., particle and heat fluxes, target n e and T e 6

PED_D3D tree structure contains both pedestal and SOL data Top-level branches for equilibrium, pedestal, and divertor data.div branch with 0-D, 1-D, and 2- D branches; time-averaged and time-resolved (for ELMs).TWOD branch contains profile data, e.g., particle and heat fluxes, target n e and T e JSATDIV: data and independent variables, run-specifics 7

PED_D3D tree structure contains both pedestal and SOL data Top-level branches for equilibrium, pedestal, and divertor data.div branch with 0-D, 1-D, and 2- D branches; time-averaged and time-resolved (for ELMs).TWOD branch contains profile data, e.g., particle and heat fluxes, target n e and T e JSATDIV: data and independent variables, run-specifics SPECTRO branch: line-emission profiles, e.g., H α, H β, CIII 8

PED_D3D tree structure contains both pedestal and SOL data Top-level branches for equilibrium, pedestal, and divertor data.div branch with 0-D, 1-D, and 2- D branches; time-averaged and time-resolved (for ELMs).TWOD branch contains profile data, e.g., particle and heat fluxes, target n e and T e JSATDIV: data and independent variables, run-specifics SPECTRO branch: line-emission profiles, e.g., H α, H β, CIII HALPHA: data, wavelength, and geometry information 9

Example: Dimensionally and operationally similar Ohmic plasmas in ASDEX Upgrade and DIII-D shot I P [MA] / B T [T] P in [MW] P rad [MW] (f rad ) <n e > [10 19 m -3 ] divertor configuration first-wall ASDEX-U 21303 1.0 / -1.9 (fwd) q 95 3.4 3.9 δ low 0.3 0.5 0.7 0.4 (57%) 2.6 Vertical (cryo) Div - C, MC - W DIII-D 119919 1.1 / -2.0 (fwd) 0.9 0.4 (44%) 2.6 Inner plate 45, outer horizontal (no cryo) Div & MC - C 10

Lower single null plasmas with vertical (AUG) and semihorizontal (DIII-D) target plate configurations Filtered line monitors (D α, CIII) Thomson Scattering (n e, T e ) Langmuir Probes (j sat ) 11

Carbon copy upstream profiles in AUG and DIII-D Upstream data mapped to flux coordinates at the outer midplane: PSIN DIII-D AUG 12

Similar particle flux profiles to outer plate, but inner plate profile suggests partially detached plasma for DIII-D Perpendicular component of j sat, obtained from strike point sweeps mapped to dssep DIII-D j sat profile for inner plate peaks ~6 cm in common flux region, for AUG at the inner separatrix Different LP probe designs: flat (AUG) versus domed (DIII-D) probe heads DIII-D x sin(θ) AUG PFR Com SOL 13

In/out asymmetric divertor D α traces are consistent with Langmuir probe measurements Nearly-normal (AUG) versus vertical (DIII-D) viewing geometries likely to affect shape and magnitude of the profiles DIII-D AUG x 10 DIII-D AUG 14

Carbon emission profile (and tangential camera data) indicative of inner divertor plasma < 2 ev for DIII-D Similar CIII emission profiles at outer plate Inner divertor CIII emission peaks in common SOL (AUG) and private flux region (DIII-D) DIII-D AUG 15

Experimental database facilitates comparison with SOLPS / UEDGE modeling database Modeling database originally developed by David Coster, IPP Garching, for SOLPS, recently adapted for UEDGE Tree structure mainly for code output Enables platform-independent code-code comparison Tree structure includes synthetic diagnostics for simulation validation against experiments Set of common independent parameters required, e.g., R-R sep at the outer midplane 16

Summary and outlook: database most useful when physics topic-driven Extension of pedestal profile database to (currently divertor) SOL Two different local versions: AUGDIV and.div in PED_D3D MDSplus-based data structure In process of finalizing tree structure for a central ITPA database Data available upon request Need to decide how we want to share the database, to transfer data, to grant access, etc. Database is a powerful tool to compare SOL profiles from different devices, and with simulations from edge codes AUG / DIII-D core plasma fueling experiment: effect of divertor geometry on divertor performance and core plasma fueling Extension of database to other devices 17