Confinement Database and Modelling Meeting 2-5 April, 2001 - Lausanne L-mode DB 2.7: new contributions from FT/FTU and some analysis G. Bracco Associazione Euratom-ENEA sulla Fusione, Frascati
Outline L mode DB vs 2.7, released 26/3/2001 L mode regressions, B t dependence Saturated OH confinement analysis New FT/FTU contribution (FT Hydrogen data) FTU data with pellet injection Conclusions
L mode DB version 2.7 TOKAMAK N DB23a BMIN BMAX H D HE3 HE4 M=1.5 ALCC 1039 6.07 12.57 113 926 ASDEX 639 98 1.01 2.82 104 535 CMOD 611 611 3.35 7.67 46 565 D3D 161 161 1.28 2.15 36 111 14 DIII 210 210 0.61 2.4 210 FT 273 2.43 9.99 20 253 FTU 300 255 2.48 8.04 22 278 JET 3516 433 1.56 3.87 156 2807 175 317 61 JFT2M 137 137 0.66 1.41 24 111 2 JT60 622 622 2.32 4.72 622 PBXM 31 31 1.25 1.36 31 PDX 51 51 0.7 2.2 51 RTP 18 1.94 2.2 18 START 21 21 0.2 0.42 21 T10 58 40 2.42 3.07 58 TDEV 14 14 1.77 1.77 14 TEXTOR 274 274 1.9 2.36 274 TFTR 409 409 1.27 4.82 14 395 TSUPRA 322 261 2.09 3.95 18 140 164 Tot: 8706 data new data since version 2.3a: ALCC, ASDEX, FT, FTU, JET, RTP, T10, TSUPRA A preliminary version 3.0 was presented at Frascati meeting Sept 2000; This version 2.7 contains the results of some clean-up work
L mode DB version 2.7: MEFF & PHASE (1) D TOKAMAK N BMIN BMAX OH L I EP ALCC 926 6.07 12.57 926 ASDEX 535 1.26 2.82 350 185 CMOD 565 3.35 7.67 339 226 D3D 111 1.28 2.15 111 DIII 210 0.61 2.4 210 FT 253 2.43 9.99 253 FTU 278 2.48 8.04 264 14 JET 2807 1.6 3.87 2543 264 JFT2M 111 0.7 1.41 111 PBXM 31 1.25 1.36 31 START 21 0.2 0.42 21 T10 58 2.42 3.07 28 30 TDEV 14 1.77 1.77 3 11 TEXTOR 274 1.9 2.36 99 82 93 TFTR 395 1.27 4.82 395 TSUPRA 140 2.96 3.88 33 65 42
L mode DB version 2.7: MEFF & PHASE (2) H TOKAMAK N BMIN BMAX OH L ALCC 113 6.23 10.05 113 ASDEX 104 1.01 2.8 52 52 CMOD 46 4.63 5.22 46 D3D 36 2.02 2.13 36 FT 20 5.97 6.06 20 FTU 22 5.72 5.82 22 JET 156 1.56 3.38 156 JFT2M 24 0.66 1.27 24 JT60 622 2.32 4.72 190 432 PDX 51 0.7 2.2 11 40 RTP 18 1.94 2.2 8 10 TFTR 14 3.51 4.14 14 TSUPRA 18 3.94 3.95 8 10 HE3 TOKAMAK NBMINBMAXOH L JET 175 1.71 3.48 175 LHEP EP M=1.5 TOKAMAK NBMINBMAXOH L LHEP EP JET 61 1.72 3.52 61 HE4 TOKAMAK NBMINBMAXOH L LHEP EP D3D 14 2.08 2.1 14 JET 317 1.62 3.7 317 JFT2M 2 1.15 1.17 2 TSUPRA 164 2.09 3.92 51 59 23 31
L mode: regression for data in DB2.3a 1498 data τ freefit =0.022 I 0.93 B 0.06 P -0.71 n 0.41 M 0.19 R 1.81 ε -0.03 k 0.69 RMSE=0.155 τ L96P(th) =0.023 I 0.96 B 0.03 P -0.73 n 0.40 M 0.2 R 1.83 ε -0.06 k 0.64 Free fit: by changing the R exponent to 1.84 the high-β constr. is fulfilled; The high-β constrained fit is practically the same Bohm ρ* dependence. Result very similar to ITERL96P(th) Selection criteria: ISELDB2=11 H, D, PHASE=L, BEILI2<2
L mode: constrained regression including new data τ constr =0.022 I 0.89 B 0.09 P -0.72 n 0.42 M 0.22 R 1.88 ε -0.05 k 0.71 RMSE=0.156 τ L96P(th) =0.023 I 0.96 B 0.03 P -0.73 n 0.40 M 0.2 R 1.83 ε -0.06 k 0.64 1704 data from 14 tokamaks new tokamaks FTU, RTP, T10 more data from TSUPRA The free fit is practically the same Bohm ρ* dependence. Result very similar to ITERL96P(th) Selection criteria: H, D, PHASE=L, BEILI2<2
L mode: TAUTH/Constr.regression versus B τ constr =0.022 I 0.89 B 0.09 P -0.72 n 0.42 M 0.22 R 1.88 ε -0.05 k 0.71 TAUTH/ τ constr Very weak magnetic field dependence in the scaling; no systematic trend. Bohm ρ* dependence. Result very similar to ITERL96P(th) B (T)
OHMIC Section Originally the OH section was composed only reference data for the additionally heated phase. Now OH data in L mode DB are the largest subset (6208 data over 8706). extended contributions: ALCC, ASDEX,CMOD,FT, FTU, JET, JT60 no data: D3D,DIII,JFT2M,PBXM,TFTR PDX,RTP,START,T10,TDEV,TEXTOR,TSUPRA few data: START: old data (higher values reported e.g. Varenna TTF 2000) TEXTOR: strange LOC data TSUPRA: SOC data? t 0.25 s (0.35 s reported in literature) PDX,RTP,T10,TDEV: SOC data? Some relevant quantities for OH confinement analysis are missing: ZEFF,TEV,TE0 (ALCC,CMOD), QEDGE(START,JT60)
OH: SOC regression A regression of the data in the Saturated OH Confinement regime (H,D, no pellet) has been performed: QEDGE has been defined for START (low aspect ratio formula) and JT60 (usual formula) SOC data selection 2 criteria: (1) critical density between LOC/SOC from Shimomura scaling : n 19 > 6.5 M 0.5 B/qR (2) τ neoa =0.007aR 2 k n 19 q >MIN defined ad-hoc for each tokamak NOH N (1) N (2) MIN ALCC 980 349 190 0.060 ASDEX 402 130 320 0.060 CMOD 385 213 167 0.080 FT 273 34 121 0.040 FTU 270 88 179 0.070 JET 1530 756 1037 0.700 JT60 189 119 125 0.500 PDX 11 9 4 0.040 RTP 8 1 START 21 18 6 0.003 T10 8 TDEV 3 TEXTOR 99 21 11 0.120 TSUPRA 41 6 8 0.300
SOC Regression (1) MEFF RGEO eps KAPPA nel19 bt ipma RMSE ITER Freefit (s) (1) 0.028 0.28 2.07 0.44 0.98 0.07 0.41 0.05 0.1841 4.23 (1) 0.028 0.31 2.05 0.47 1.02 0.51 0.1855 3.76 (2) 0.026 0.26 2.19 0.44 1.10 0.12 0.35-0.04 0.1759 4.01 (2) 0.028 0.26 2.01 0.33 1.04 0.41 0.1778 3.44 Constrained (1) 0.031 0.276 2.02 0.649 1.03 0.616 0.1964 3.76 (2) 0.029 0.182 1.96 0.474 1.14 0.57 0.2000 3.54 0.030 0.2 2 0.5 1 0.6 3.77 ITER-FEAT 2 6.2 0.32 1.85 6 5.3 15 τ SOC =0.03 B 0.6 R 2 ε 0.5 M 0.2 k τ SOC =0.09 B 0.6 R 2 ε τ SOC =0.05 B R 2 ε M 0.5 k 0.5 ZUO, EPS1995,TORE SUPRA NeoAlcator at n 19 =6.5 M 0.5 B/qR (ITER Physics Basis)
SOC Regression (2) τ SOC =0.03 B 0.6 R 2 ε 0.5 M 0.2 k τ SOC =0.05 B R 2 ε M 0.5 k 0.5 NeoAlcator at n 19 =6.5 M 0.5 B/qR [SOC data selected by the criteria τ neoa =0.007aR 2 k n 19 q >MIN(TOK)]
SOC Regression (3): B dependence TAUTH/τ SOC TAUTH/τSOC τ SOC =0.03 B 0.6 R 2 ε 0.5 M 0.2 k B freefit τ SOC =0.028 B 0.41 R 2.01 ε 0.33 M 0.26 k 1.04 A weak trend with B is observed with the constrained fit [SOC data selected by the criteria τ neoa =0.007aR 2 k n 19 q >MIN(TOK)] B
Pellet injection in OH plasma: ALCC, FTU FTU TAUTH NeoAlc TAUTH/τ SOC ALCC TAUTH NeoAlc B Energy confinement time can increase up to a factor 2 compared to SOC values with pellet injection
Conclusions L mode DB version 2.7 is in a better shape compared to the last meeting in Frascati, Oct.2000 L mode data regression confirms the results summarized by scaling ITERL96p(th) A scaling for saturated ohmic confinement has been obtained.