L-H threshold database: Status and Plans J.W. Hughes, J. Stillerman, MIT PSFC Y. Martin, CRPP-EPFL P. Gohil, GA D. McDonald, JET-EFDA ITPA Transport & Confinement Topical Group Meeting Naka, Japan 2 April 2009

ITPA-TC. Naka, 2 April L-H threshold database is changing hands, expanding MIT will begin administering the L-H transition database in 2009 –Server purchased and expected to be operational in May ‘09 –Supported by PSFC computing personnel –Accessible to ITPA participants –Community usage, openness encouraged Reduced role of centralized administration Simple password authentication for ease of access Development of APIs to allow ease of data extraction, insertion for individual users –Nightly backups plus version archiving following publications Two stage development envisioned –Existing scalar power threshold database, on an SQL server –Profile data, stored in standardized MDSplus tree structures (analogous to existing profile databases used by Pedestal, DIV/SOL groups)

ITPA-TC. Naka, 2 April Ideas for profile database development Participants in database effort should determine composition of profile DB Content driven by priorities, key goals of researchers (see next slide) Data sets should be sufficient to provide useful profiles, but not so extensive as to discourage participation A possible model is a tiered data set –Tier 1. Global parameters:, BT, IP, etc. (plus d/dt of each) –Tier 2. Essential profiles: ne,i, Te,i, vif, viq et al. –Tier 3. Profiles requiring analysis: Poh, Paux, jBS et al. –Tier 4. Advanced profile measurements: Prad, n0, flucts. et al.

A goal oriented threshold DB Optimize effectiveness of DB effort with clear goals, determined by the participants Profile data for model testing –Profile evolution across the L-H Transition –New dedicated DB or profile DB with cases labelling? –Participation of modellers in definition of set of variables –ITER requirements Profile data for reducing the uncertainty in P thresh prediction –Identification of important parameters in individual devices –Agreement on set of variables (depending on current JEX?), filling the DB and analysis ITPA-TC. Naka, 2 April

A goal oriented threshold DB (II) Profile data for predictive capabilites (ITER) –Short term: 0D (and some 1D?) approach based on JEX results –Long term: simulations based on validated models JEX to reduce the uncertainty –Comparison between devices of L-H trans. –Analysis of the targeted dependence –Reduction of the uncertainty by ‘inserting the parameter’ Description of present knowledge and remaining issues –Paper to be initiated at the Princeton meeting Preparation of the Princeton meeting –Strongly dedicated to L-H transitions? ITPA-TC. Naka, 2 April