1 / 19

SOLPS5 simulations of ELMing H-mode

SOLPS5 simulations of ELMing H-mode. Barbora Gulejov á Richard Pitts, David Coster, Xavier Bonnin, Roland Behn, Marc Beurskens, Stefan Jachmich, Jan Horáček, Arne Kallenbach. OUTLINE. SOLPS 5 code package ELM simulation - theory Simulation of Type III ELM at TCV

gyala
Télécharger la présentation

SOLPS5 simulations of ELMing H-mode

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SOLPS5 simulations of ELMing H-mode Barbora Gulejová Richard Pitts,David Coster, Xavier Bonnin, Roland Behn, Marc Beurskens, Stefan Jachmich, Jan Horáček, Arne Kallenbach

  2. OUTLINE SOLPS 5 code package ELM simulation - theory Simulation of Type III ELM at TCV Simulation of Type I ELMing H-mode at JET Code - experiment benchmark Code - code benchmark * * * * * *

  3. MOTIVATION ELMing H-mode = baseline scenario for plasma operation on ITER! Edge localised mode (ELM) H-mode  Edge MHD instabilities Periodic bursts of particles and energy into the SOL ELM leaves edge pedestal region in the form of a helical filamentary structure localised in the outboard midplane region of the poloidal cross-section Danger:  divertor targets and main walls erosion  first wall power deposition Energy stored in ELMs: TCV  500 J JET  200kJ ITER ~ 1-10 MJ => unacceptable Understanding of the ELM from formation to point of interaction with plasma facing components = Important research goal!

  4. SOLPS5 modelling of ELMing H-mode *contribute to understanding transport in the SOL : transient events => ELMs * interpretative modeling of both 1.) steady state and 2.) transient particle and heat fluxes during ELMing H-mode employing the SOLPS5 fluid/Monte Carlo code * rigorous benchmarking = seeking the possible agreement between 1.) experiment and simulation 2.) code and different code MODEL: tool to understand and predict phenomena => 1.) • Type III & Type I ELMing H-mode • TCV & JET • benchmark SOLPS & EDGE2D/NIMBUS 2.a) 2.b)

  5. Scrape-Off Layer Plasma Simulation Suite of codes to simulate transport in edge plasma of tokamaks B2 - solves 2D multi-species fluid equations on a grid given from magnetic equilibrium EIRENE - kinetic transport code for neutrals based on Monte - Carlo algorithm SOLPS 5 – coupled EIRENE + B2.5 Mesh plasma background => recycling fluxes 72 grid cells poloidally along separatrix 24 cells radially B2 EIRENE Sources and sinks due to neutrals and molecules Main inputs: * magnetic equilibrium * Psol = Pheat – Pradcore * upstream separatrix density ne *EELM Free parameters: cross-field transport coefficients (D┴, ┴, v┴) measured systematically adjusted D0 D1+ C0 C1+ C2+ C3+ C4+ C5+ C6+

  6. Type III ELMing H-mode on TCV ELMs - too rapid (frequency ~ 200 Hz) for comparison on an individual ELM basis => Many similar events are coherently averaged inside interval with reasonably periodic elms telm ~ 100 μs tpost ~ 1 ms tpre ~ 2 ms Pre-ELM phase Post-ELM phase ELM = particles and heat are thrown into SOL ( elevated cross-field transport coefficients) Time-dependent ELM simulation * starting from time-dependent pre-ELM steady state simulation * equal time-steps for kinetic and fluid parts of code, dt = 10-6 s

  7. Pre-ELM and ELM simulation - theory Cross-field radial transportin the main SOL - complex phenomena Ansatz:( D┴, ┴, v┴) – variation : radially – transport barrier (TB) poloidally – no TB in div.legs 2 approaches * Pure diffusion: v┴=0 everywhere * More appropriate: Convection simulations with D┴= D┴class Simulation of ELM Instantaneous increase of the cross-field transport parameters D┴, ┴, v┴! 1.) for ELM time – from experiment coh.averaged ELM = tELM = 10-4s 2.) at poloidal location -> expelled from area AELM at LFS Cross-field radial transport => approximate estimation of transport parameters during ELM corresponding to the given expelled energy WELM, tELM and AELM AELM= 1.5m2 W = 600 J 20 * D┴ ┴ 40 0 20

  8. Type III TCV ELM simulation ELM is more convective than conductive ! Upstream TS measurements (R.Behn et al., PPCF 49 (2007)) => larger drop in ne than Te at the pedestal top => <Teped>Δ.nepedexceeds <neped>Δ.Teped in the contribution to EELM => SOLPS : D increased more then  during the ELM 100times 10 times (2 times in SOL) + change of radial shape ! ETB collapse! AELM=1.5m2 – Gaussian function of multiplicators polloidally 1 ELM cycle of total 400 μs, * 100 μs before ELM * ELM duration = tELM = 100μs =100 points during ELM event * 200 μs after ELM smaller TB D┴ ┴ Very good agreement !

  9. Type III TCV ELM simulation Downstream SOLPS < Exp (LP) factor ~ 1.5 SOLPS >> Exp (coav LP) ( R.Pitts,Nucl.Fusion 43 (2003)) factor ~ 3

  10. Type I ELMing H-mode on JET Succesfully modelled by EDGE2D + NIMBUS by Arne Kallenbach (PPCF 46,2004) # 58569 Parameters Bt = 2 T Ip = 2 MA ne= 4x1019 m-3 P(SOL)= 12 MW GAS PUFF from inner divertor !! Dalpha PIN ~ 14 MW PRAD (core) ELM parameters felm ~ 30 Hz ΔWELM ~ 200 kJ Wdia CoreLIDAR Edge LIDAR Li beam ECE time

  11. Benchmarking code-code SOLPS 5 B2.5 + EIRENE fluid (Braginskii) kinetic (Monte Carlo), neutrals vs. EDGE2D + NIMBUS fluid (Braginskii) kinetic (Monte Carlo), neutrals (less complex then EIRENE!)

  12. Pre-ELM model vs.experiment EDGE2D+NIMBUS SOLPS5 2 2 Same Ansatz D,Chi,v Same ne,Te,Ti upstream profiles -0.05 0.05 0 r-rsep [m]

  13. Pre-ELM vs. ELM simulation EDGE2D+NIMBUS SOLPS5 ELM D x 20 Chi x 40 1ms 0.05 -0.05 0.05 0 0.05 0.05 -0.05 0 0.1

  14. Model vs. experiment-targets(LP) outer target inner target outer target EDGE2D+NIMBUS SOLPS5 250 300 LP 25 25 5 7 r-rsep map2mid r-rsep map2mid

  15. Type I ELMing H-mode on JET =baseline scenario for QDT=10 burning plasma operation on ITER !!! To avoid divertor damage => maximum ΔWELM (ITER) ~ 1MJ(at TCV 0.005 MJ !!!) = this is achievable on JET # 70224 Parameters Bt = 3 T Ip = 3 MA ne=6x1019 m-3 P(SOL)= 19 MW No GAS PUFF !! ν*ped ~0.03 -0.08 (expected for ITER!) CoreLIDAR Edge LIDAR Li beam HRTS ECE Dalpha PIN ~ 20 MW PRAD(below Xpoint) PRAD (core) ELM parameters felm ~ 2 Hz ΔWELM ~ 1 MJ Langmuir probes Wdia Bolometry (A.Huber) radiation between ELMs Simulated for the first time ! … with SOLPS5 time

  16. Simulation vs. experiment - upstream ne [m-3] First results for pre-ELM Te [eV] D┴= 0.01 m2.s-1 in pedestal 1 m2.s-1 in SOL Χ┴= 0.7 m2.s-1 in pedestal 1 m2.s-1 in SOL (TCV pedestal: D┴= 0.007 m2.s-1 Χ┴= 0.25 m2.s-1 ) D[m2.s-1] Χ[m2.s-1] CoreLIDAR Edge LIDAR Li beam HRTS ECE * quite promising * unlike for TCV inward pinch radial profile necessary!! vperp [m.s-1] inward pinch!

  17. Simulation vs.experiment - targets SOLPS LP Inner target Outer target LP 80 50 50 30 1,2 0.5 r-rsep r-rsep r-rsep map2mid r-rsep map2mid Inner target – good agreement Outer target SOLPS Te too high!

  18. CONCLUSIONS Type III ELMing H-mode at TCV and Type I ELMing H-mode at JET have been succesfully simulated by SOLPS5 both steady state and transient event Agreement obtained between : code - experiment code - code * * * * * *

  19. Thank you for attention !

More Related