Multi scale drift turbulence dynamics in an Ohmic discharge as measured at the FT tokamak and modelled by full f gyrokinetic ELMFIRE code E. Gusakov1, V. Bulanin, A. Gurchenko1, J. Heikkinen3, S. Janhunen4, S. Leerink4, A. Altukhov1, L. Esipov1, M. Kantor1, D. Kuprienko1,T. Kiviniemi4,T. Korpilo4, S. Lashkul1, and A. Petrov 1 Ioffe Institute, Russia St. Petersburg State Polytechnic University, Russia 3 Euratom Tekes Association, VTT, Finland 4 Euratom Tekes Association, Aalto University, Espoo, Finland
FEC1 EX/7 and TH/6 11.1.1 Contents of this talk 1.Introduction to ELMFIRE, Doppler reflectometry and Enhanced Scattering.Profiles and transport properties 3.DR spectra comparison 4.Poloidal velocity comparison 5.Electric field statistics comparison 6.Comparison on spatial structure of GAM 7.Conclusions
FEC1 EX/7 and TH/6 11.1.1 FT tokamak (Ioffe Institute) R = 55 cm a = 8 cm Bt <.7 T Ip < 5 ka Ne < 7 119 m 3 Te < 1. kev Ti <.4 kev
FEC1 EX/7 and TH/6 11.1.1 Microwave Doppler reflectometry k =ks- ki FT- 37 GHz 16 k k =kisin(α ) k ks ki Synthetic diagnostic 1 k α 6 I(t)= w(r,θ) δn(r,θ,t) r dr dθ 5 W(r,θ)=wcos+i*wsin B kant 4 3 V =VExB+Vph x, cm π fd=kv=k V E (O-mode) 1 6 7 r, cm 8-1 The synthetic diagnostic is constructed using the complex instrumental DR weighting function. (S.Leerink CPP'1 5)
FEC1 EX/7 and TH/6 11.1.1 ER (arb.un.) kr (arb.un.) Microwave Enhanced scattering in UHR kir ksr EiR ; EsR Doppler frequency shift qr R - RUH R (arb.un.) PES (norm. arb.un.) fd (MHz) res~5.7 cm 6 8 3 3 34 t 36 (ms) ES spectrum 1 ωi = ωce + ωpe t~1.6ms 63 aver. t~3.mks no aver. fi =66 GHz t ~9 ms regime 1 19 ka -6-4 - 4 fω (MHz) 6 4 fd-spectrum 4 8 F1 (khz) π f D = qθvθ fω = fs - fi Gusakov et al. PPCF'6 48 Gurchenko et al. PPCF'1 5
FEC1 EX/7 and TH/6 11.1.1 Gyrokinetic full f code: ELMFIRE ELMFIRE properties: Gyrokinetic electrostatic 5D full f particle code. Species: e,i, impurity. Binary collision model. Quasineutrality enforced through polarization drift and electron parallel non linearity. Applicable for kinetic analysis of neo classical physics and microturbulence. Heikkinen et al. JCP '8 & '11, PoP'1 Instantaneous density fluctuation normalized to flux surface averaged density, poloidal section.
FEC1 EX/7 and TH/6 11.1.1 Profiles and transport results t ~ 8.3 9.9 ms Ip ~ 19 ka BT ~. T ν* ~ 1 5 τe ~ 1 ms hydrogen plasma main impurity: oxygen O+6 Zeff ~ 3.1 TH+ = TO+6 assumed
FEC1 EX/7 and TH/6 11.1.1 Profiles and transport results (ctd) ASTRA modeling: G.V. Pereverzev and P.N. Yushmanov, preprint IPP 5/98 Garching
FEC1 EX/7 and TH/6 11.1.1 Poloidal rotation profiles compared Poloidal rotation profiles were measured with Enhanced Scattering, Doppler Reflectometry and from ELMFIRE.
FEC1 EX/7 and TH/6 11.1.1 Doppler reflectometry spectra DR spectra were compared to the synthetic diagnostic. Shift, width and shape reproduced. S.Leerink et al. PRL'1, accepted for publication
FEC1 EX/7 and TH/6 11.1.1 Er evolution in time The experimental signal is low pass filtered with a Nyquist frequency of FN = 156.5 khz. This has to be taken into account in analysis of simulation data.
FEC1 EX/7 and TH/6 11.1.1 Er fluctuation statistics
FEC1 EX/7 and TH/6 11.1.1 Comparison of GAM frequencies
FEC1 EX/7 and TH/6 11.1.1 GAM correlation measurements with ES ES points for central rays and 3 db-spots on the UHR for fi = 54-68 GHz y (cm) 6 5 m.s. 4 3 1 3 4 5 6 x (cm) 7 Enhanced scattering allows correlation measurements if two signals are measured, f f1 < 4 GHz corresponds to ΔL < cm in plasma
FEC1 EX/7 and TH/6 11.1.1 GAM correlation measurements with ES -.6 1..5 -.3 1..5 -.3. -.5.3-1. Re -1.5 3 6-1. -.4 1..5. -.5.1.4-1. Im -1.5 3 6 1.5.6 F (khz).5.3-1..8-1.5.9 6 9 1 15 18 F (khz) 9 1 15 18.9 -.6.3-1. Im -1.5..6 3 6 3 6 Coherence: -.5 3 -.3.5.. -.5 9 1 15 18 coh{fd1;fd} 1. L -.1 (cm) 1.5 1..5 Vr direction: radially outwards.6 Re -1.5.9 -.6 (cm) 9 1 15 18.6 1.5 1..5. -.5-1..6 9 1 15 18 F (khz)..3.5.6 coh{er1;er} -1.5 3 6 9 1 15 18 F (khz).7.9 cross-phase π( /).3 L. -.5 (cm) (cm) L64.1 GHz (cm) 1.5 1.5 L64.1 GHz Elmfire: Er1 & Er -.6 L L64.1 GHz (cm) ES: two fd signals 1.5 3 1-1 - -3 F ~ 5 khz Er ELMFIRE fd ES -1 L (cm) 1
FEC1 EX/7 and TH/6 11.1.1 Conclusions Good correspondence between experimental and simulation data have been obtained: For transport properties. Doppler reflectometry, and ES measurements of Mean E B flows. DR spectra. Oscillations in zonal flows. GAM spatial correlation properties. Clear influence of an impurity species is observed.
FEC1 EX/7 and TH/6 11.1.1 Acknowledgements This work is supported by the grants 1435 and 134977 of the Academy of Finland, RFBR grant 1 631, the Russian Academy program 1, the RF Government grant 11.G34.31.41, the EFDA Topical Group Activities and is part of the national Tekes work program. The High Level Support Team and the CSC IT Center for Science Ltd. CSC, DEISA, PRACE and HPC FF are acknowledged for the allocation of manpower and computational resources for this work.