Code-Code comparisons

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1 19/11/ ITPA Coster Code-Code Code-Code comparisons D. P. Coster*, X. Bonnin** *Max Planck Institute for Plasma Physics, EURATOM Association, Garching, Germany ** Max Planck Institute for Plasma Physics, EURATOM Association, Greifswald, Germany; CEA- France; Paris-XIII

2 Goal Three major edge codes in wide-spread use, and in use for JET discharges Two of these with developer knowledge at JET To compare the edge codes for a series of cases with increasing physics complexity, to understand the origin of the differences that arise, and to validate the codes Started with EDGE2D-NIMBUS, SOLPS (B2-EIRENE) and UEDGE Lack of UEDGE expertise at JET caused UEDGE to drop out (welcome to join back, do need developer level expertise to be available, though) Progression D, no drifts [completed] D, drifts [started] D+C, no drifts [next] D+C, drifts [last]

codes Started with EDGE2D-NIMBUS, SOLPS (B2-EIRENE) and UEDGE Lack of UEDGE expertise at JET caused UEDGE to drop out (welcome to join back, do

3 SOLPS/EDGE2D-NIMBUS comparison, first results Starting point for the comparisons Pure D Same transport coefficients Same boundary conditions Same feedback gas puff to control separatrix density Strong differences 3 cases EDGE2D-NIMBUS SOLPS, fluid neutrals SOLPS, kinetic neutrals Suggested we had a lot of work ahead

feedback gas puff to control separatrix density Strong differences 3 cases

4 Some observations Comparisons facilitated by Being able to operate the codes on the same grid Being to plot the results from both codes on the same graph, easily Did this by porting the JET TRAN file facility to SOLPS Not necessarily the best long term solution But could be done quickly Having Developer-level expertise for both codes available at the same site for extended periods of time Having sufficient computer resources available

Not necessarily the best long term solution But could be done quickly Having Developer-level expertise for

5 SOLPS/EDGE2D-NIMBUS comparison, flux limiters First big difference traced to different assumptions about kinetic parallel electron and ion energy flux limiters SOLPS had been using flux limiters for both electrons and ions EDGE2D-NIMBUS had the electron flux limiters coded, but not used in these runs Having the same flux limiter choice in both codes brought the two closer together

flux limiters for both electrons and ions EDGE2D-NIMBUS had the electron flux limiters coded,

6 SOLPS/EDGE2D-NIMBUS comparison, additional differences Also explained a feature that had been seen on the poloidal ion temperature profile --- eliminated when ion thermal flux limiter switched off Feature also decreased when the gas puff was switched from localised (SOLPS) to distributed (EDGE2D-NIMBUS) An additional difference in the starting cases was traced to M=1 vs M>=1 at target

switched off Feature also decreased when the gas puff was switched from localised (SOLPS) to

7 SOLPS/EDGE2D-NIMBUS comparison, final 5e18 Final version of the pure D, no drifts comparison 5e18 upstream density Agreement is very good! Though differences remain Not thought worth spending too much more effort chasing the remaining differences Particularly as Some of the difference thought to come from neutrals The drift cases were calling

Though differences remain Not thought worth spending too much more effort chasing the

8 SOLPS/EDGE2D-NIMBUS comparison, final 1e19 Final version of the pure D, no drifts comparison 1e19 upstream density Slightly worse comparison than the lower density case Suspect this is due to different neutral treatment See next slide Agreement is still good

worse comparison than the lower density case Suspect this is due

9 SOLPS/EDGE2D-NIMBUS comparison, final 1.5e19 Final version of the pure D, no drifts comparison 1.5e19 upstream density Starting to see differences that come (probably) from differences in the neutrals code (NIMBUS vs EIRENE) Is an effort to produce EDGE2D- NIMBUS To see some of the effects, SOLPS cases were done dropping the energy per ionisation

5e19 upstream density Starting to see differences that come (probably) from

10 SOLPS/EDGE2D-NIMBUS comparison, drifts 5e18 With drifts 5e18 case PRELIMINARY!

11 SOLPS/EDGE2D-NIMBUS comparison, drifts 1e19 With drifts 1e19 case PRELIMINARY!

12 SOLPS/EDGE2D-NIMBUS comparison, drifts/poloidal velocities Poloidal profiles of the velocity for 5e18 and 1e19 cases Work has been on hold for some months JET not in operation, therefore no secondments Xavier shifting jobs, David busy with other things High priority for 2005

hold for some months JET not in operation, therefore no secondments

13 19/11/ ITPA Coster Code-Code MDSPLUS used to store SOLPS runs SOLPS [JET, IPP, ] New postprocessing routine b2md Communicates via TCP/IP solps-mdsplus. aug.ipp.mpg.de (MDSPLUS server) [Garching] Linux server 1GB RAM 2 cpus Using MR-AFS to provide storage shots 307 GB data In the Garching DMZ Analysis program (jetdsp, cview, radisplay, idl, matlab) [Fusion Lab] Any of the standard MDSPLUS experimental plotting programs can be used Data can be also be accessed via IDL, MATLAB

de (MDSPLUS server) [Garching] Linux server 1GB RAM 2 cpus Using MR-AFS to provide storage 11062 shots 307 GB data In the

14 Web site contains MySQL index 19/11/ ITPA Coster Code-Code

15 Code and Experiment can be plotted with the same tool CIII emission from experiment and code plotted with cview AUG data AB:10817/+solps/diag/\top.AUG.DIA:CIII_4650@ AE:*/*/*/AA_raw & time=aa_time_raw & rhv=rhv+1.08@ AG:*/*/*/AC_raw & time=aa_time_raw & rhv=0.4+rhv@ cview-prof (gdc) v User: dpc - Mon Oct 25 11:25: s coord (m) 19/11/ ITPA Coster Code-Code

000000 AE:*/*/*/AA_raw & time=aa_time_raw & rhv=rhv+1.08@3.7488 AG:*/*/*/AC_raw & time=aa_time_raw & rhv=0.4+rhv@3.

Advanced spatial discretizations in the B2.5 plasma fluid code

Advanced spatial discretizations in the B2.5 plasma fluid code Klingshirn, H.-J. a,, Coster, D.P. a, Bonnin, X. b, a Max-Planck-Institut für Plasmaphysik, EURATOM Association, Garching, Germany b LSPM-CNRS,