FOM Institute for Plasma Physics Rijnhuizen Association EuratomFOM

FOM - Institute for Plasma Physics Rijnhuizen Association Euratom-FOM Diagnostics and Control for Burning Plasmas Discussion All of you

Association Euratom-FOM Trilateral Euregio Cluster Discussion • Where are we? • Where do we want to go? • How do we get there? • Try to define the key issues in the field of control and diagnostics on which further R&D and testing is urgently needed (eg. on present machines)? A. J. H. Donné, W 60 Workshop on Burning Plasma Physics and Simulation, Tarragona, 4 -5 July 2005

Association Euratom-FOM Trilateral Euregio Cluster Proposal for discussion points • What further steps are needed in dedicated/ integrated plasma control? • What are the specific measurement challenges associated with real time control requirements in burning plasmas? • What diagnostics do need (or would benefit from) R&D on present devices? A. J. H. Donné, W 60 Workshop on Burning Plasma Physics and Simulation, Tarragona, 4 -5 July 2005

Association Euratom-FOM Trilateral Euregio Cluster Key aspects in control – 1/7 • Equilibrium control – AC losses – power management – full scenario robustness – development of control matrix for shape and position with minimum coupling between the terms – modeling of breakdown phase A. J. H. Donné, W 60 Workshop on Burning Plasma Physics and Simulation, Tarragona, 4 -5 July 2005

Association Euratom-FOM Trilateral Euregio Cluster Key aspects in control – 2 a/7 • MHD control – Control of NTM’s, sawteeth (yesterdays disc. ) • Interaction with pellets • ECRH stabilization – Control of RWM’s • • • Interaction with pellets RFA extrapolation to ITER? Internal coils needed in ITER What is ‘ideal wall’ in ITER? Coupling to ELMs, NTMs – disruption avoidance and mitigations, A. J. H. Donné, W 60 Workshop on Burning Plasma Physics and Simulation, Tarragona, 4 -5 July 2005

Association Euratom-FOM Trilateral Euregio Cluster Key aspects in control – 2 b/7 • MHD control – ELM control, etc. • • • Pellet ELM triggering Decouple ELM amplitude from pedestal height ELM location (deeper in plasma gives larger ELMs) Extrapolation of ELM-free QH mode to ITER? Control by ergodic fields (pure type II regime? ) A. J. H. Donné, W 60 Workshop on Burning Plasma Physics and Simulation, Tarragona, 4 -5 July 2005

Association Euratom-FOM Trilateral Euregio Cluster Key aspects in control – 3/7 • Current profile control – Development of response matrix – effect of a-heating on current profile • Frozen-in-fields (may require ultra-slow fusion power ramp up!) – mode conversion current drive – real-time equilibrium codes incl. bootstrap current and loop voltage profile • Bootstrap current driven by fusion power may initiate a current hole A. J. H. Donné, W 60 Workshop on Burning Plasma Physics and Simulation, Tarragona, 4 -5 July 2005

Association Euratom-FOM Trilateral Euregio Cluster Key aspects in control – 4/7 • Transport barrier control – Identification of key parameters to control ITBs – role with current profile – simulation of ITB control in presence of aheating – interrelation between ETB and ITB A. J. H. Donné, W 60 Workshop on Burning Plasma Physics and Simulation, Tarragona, 4 -5 July 2005

Association Euratom-FOM Trilateral Euregio Cluster Key aspects in control – 5/7 • Power control and particle exhaust – Methods for erosion/deposition control – control & monitoring of tritium inventory – edge power dissipation control in ELMy Hmode and ITB scenarios – validation of models of He-ash removal – real-time measurement and control of D/T ratio, – compatibility with good confinement A. J. H. Donné, W 60 Workshop on Burning Plasma Physics and Simulation, Tarragona, 4 -5 July 2005

Association Euratom-FOM Trilateral Euregio Cluster Key aspects in control – 6/7 • Control of steady state scenarios – Fuelling: • how to increase density without destroying barrier (or without perturbing the beneficial pressure profile shape? • NBI fuelling rates much lower then present devices • HFS injection needed for pellets • CT injection? Modeling for ITER. Localization of fuelling. Test on present device (NSTX). – Impurity accumulation and exhaust – disruptivity – develop scenarios with minimum control – control of current and loop voltage under high bootstrap conditions. A. J. H. Donné, W 60 Workshop on Burning Plasma Physics and Simulation, Tarragona, 4 -5 July 2005

Association Euratom-FOM Trilateral Euregio Cluster Key aspects in control – 7/7 • Other – Integration of all aspects of control (control architectures and methodologies) • Based on dynamic models for transients • Simulate burning plasma conditions in DT exp. W. ICRH – – – pre-emptive control (e. g. disruption avoidance), diagnostic requirements on basis of adequacy for control use modeling calculations for sensor development, measurement requirements indicators for possible loss of a confinement. A. J. H. Donné, W 60 Workshop on Burning Plasma Physics and Simulation, Tarragona, 4 -5 July 2005

Association Euratom-FOM Trilateral Euregio Cluster Diagnostic issues • Contamination of beam ions in confined alpha diagnostics • Development of escaping alpha diagnostics • Testing of new – ITER relevant – techniques on present devices • FW reflectometer: coupling of antennas into plasma • Requirements on fast ions/alphas in velocity space • Environmental effects • Simultaneous control • First mirrors • R&D on phenomena, components, techniques A. J. H. Donné, W 60 Workshop on Burning Plasma Physics and Simulation, Tarragona, 4 -5 July 2005

Association Euratom-FOM Trilateral Euregio Cluster Specific measurement challenges related to control • Impact of the various control issues on the measurement scenarios A. J. H. Donné, W 60 Workshop on Burning Plasma Physics and Simulation, Tarragona, 4 -5 July 2005

Association Euratom-FOM Trilateral Euregio Cluster Aims as defined by organizers • diagnostic needs and current developments (eg. diagnostics for fast particle thermalisation, redistribution and loss; neutron yields, fluxes, spectra and tomography; helium ash and helium pumping efficiency; plasma isotopic composition; erosion, redeposition and tritium retention; and other specific diagnostic challenges for burning plasmas); • advances in integrated plasma control and dedicated control (eg. of MHD instabilities); • specific measurement challenges associated with real time control requirements in burning plasmas (eg. sensors, actuators and modelling for D-T mixture control, burn control, current and pressure control with aparticle driven sources). A. J. H. Donné, W 60 Workshop on Burning Plasma Physics and Simulation, Tarragona, 4 -5 July 2005