Status of H-mode confinement Database by K. Thomsen, Naka, September 2007  New version DB4v5 (12395 obs) - New data from AUG, DIII-D, JT-60U, NSTX - Hybrid data are marked with variable HYBRID (= YES, IH, HYBRID ) - New rotation variables defined by S. Kaye  List of variables has been updated

Definitions of Rotation and Torque Variables Rotation variables to be cast in terms of rotation frequency W, where W=2pVtor/L, where L=2pRlocal, so that W=Vtor/Rlocal. Rlocal is R at the point of measurement. Units are sec-1. Rotation Variables OMEGAIMP0 – Rotation frequency of impurities in center of plasma OMEGAIMPH – Rotation frequency of impurities at the half radius OMEGAM0 – Rotation frequency of the main plasma species in the center OMEGAMH – Rotatoin frequency of main plasma species at the half radius SPIN – As defined in attached document Torque Variables – Units are Newton-meters TORQ – As defined in attached document TORQBM – Volume-integrated torque due to beam (as calculated in TRANSP, for instance) = TORQ if no (e.g.) TRANSP calculation exists TORQIN – Volume-integrated total input torque (this could be a combination of beam torque + torque due to applied or intrinsic error fields). = TORQBM if no additional torques are to be considered

Hybrid characterisation New variables: fBS, rho(q=2), TauCR, inversion radius, ITB flags

 Web page with documentation and access to different formats of the Db4v5 database  Pedestal DB DB3v2 was combined w. DB3 e.g. HDB3v13_PDB3v2 – 656 obs.  Pedestal DB DB3v3 has been combined w. DB4v3 (HDB4v3_PDB3v3) – 688 obs.

Results from HDB3v11_PDB3v2 Nuclear Fusion 43 (2003) Table 4. The confinement time predictions for ITER and FIRE for various models. RMSE ITERFIRE (%)τε (s) Wped/Wth τε (s) Wped /Wth (a) One-term IPB98(y,2) —0.94— PedestalCore (b) Thermal conduction equation (2)Equation (7) (c) Thermal conduction equation (2)Equation (6) (d) MHD limit equation (5)Equation (8) (e) MHD limit equation (5)Equation (6)

Results from HDB3v11_PDB3v2 5. Summary The data in the joint pedestal database has been fitted to two different types of model: the thermal conduction and MHD limit models. The two models give rise to a prediction for the pedestal stored energy in next step devices varying from 28% to 50% of the total stored energy. Although the thermal conduction model gives a tighter fit to the present data set than the MHD limit model, the MHD limit model cannot be fully excluded due to the limited condition of the present database. To improve the condition of the database, larger ranges of power and current are needed from each device and further pedestal data are needed from smaller devices such as JFT2M or COMPASS. To break the Fq, ε correlation a large range of differently shaped discharges is required from all devices. Using these pedestal models, two two-term models have been developed which give a good fit to the ELMy H-mode database DB3v11. These two models give confinement time predictions for both ITER and FIRE which are close to those of the one-term model IPB98(y,2), which is currently being used to predict the performance of next step devices.

References Two term scaling IAEA 2002 Two term scaling Nuclear Fusion J Snipe Poster IAEA 2002 DB3v13 paper