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This paper gives an overview of the scope and context of the CODAC high-level real-time applications (Supervision and Plasma Control) and presents the strategy and current state of design of the tools to support the implementation. A real-time framework, which is currently under development with strong support of the worldwide fusion community will not only support the implementation of plasma control strategies with the extensive exception handling and forecasting functionality foreseen for ITER, but also integrated commissioning, orchestration and supervision as well as the real-time needs of ITER plant system developers. A second cornerstone in the implementation strategy is the development of a powerful simulation environment (Plasma Control System Simulation Platform - PCSSP) to design and verify control strategies, event handling and orchestration and automation. The development of PCSSP is currently under contract and this paper will also give an overview of its current state of development. (C) 2015 ITER Organization. Published by Elsevier B.V. All rights reserved.

In view of the preparation for the operation of the ITER tokamak it is necessary to develop the plasmascenarios taking into account all engineering constraints coming from the plant and including a realisticcontrol system. It is important to consider that, due to the high energy of ITER plasmas, much morestringent requirements are posed on the control of transients in order to avoid machine damage.Several activities are performed in the EU focusing on one side on the scenario optimization from aphysics point of view and on the other side on the design and modeling of a realistic plasma controlsystem driving the plasma configuration throughout the whole pulse and suitable for implementationon a real machine.The issues related to the computation of the control feed-forward component are addressed. In par-ticular, the possibility to trigger a feed-forward component to solve controllability problems arising inthe transitions from plasma L to H and H to L modes is studied in detail with the support of linear andnon-linear simulations.A control strategy is designed and tested on non-linear simulations of the whole pulse, including linearand non-linear effects due to controller switching, plasma shape reconstruction and power supplies.The paper reports on the results of the studies performed and discuss the proposed design of the plasmacontrol system.© 2014 Published by Elsevier B.V.

A simulation environment known as the Plasma Control System Simulation Platform (PCSSP), specifically designed to support development of the ITER Plasma Control System (PCS), is currently under construction by an international team encompassing a cross-section of expertise in simulation and exception handling for plasma control. The proposed design addresses the challenging requirements of supporting the PCS design. This paper provides an overview of the PCSSP project and a discussion of some of the major features of its design. Plasma control for the ITER tokamak will be significantly more challenging than for existing fusion devices. An order of magnitude greater performance (e.g. [1] , [2] ) is needed for some types of control, which together with limited actuator authority, implies that optimized individual controllers and nonlinear saturation logic are required. At the same time, consequences of control failure are significantly more severe, which implies a conflicting requirement for robust control. It also implies a requirement for comprehensive and robust exception handling. Coordinated control of multiple competing objectives with significant interactions, together with many shared uses of actuators to control multiple variables, implies that highly integrated control logic and shared actuator management will be required. It remains a challenge for the integrated technologies to simultaneously address these multiple and often competing requirements to be demonstrated on existing fusion devices and adapted for ITER in time to support its operational schedule. We describe ways in which the PCSSP will help address these challenges to support design of both the ITER PCS itself and the algorithms that will be implemented therein, and at the same time greatly reduce the cost of that development. We summarize the current status of the PCSSP design task, including system requirements and preliminary design documents already delivered as well as features of the ongoing detailed architectural design. The methods being incorporated in the detailed design are based on prior experience with control simulation environments in fusion and on standard practices prevalent in development of control-intensive industrial product designs.

This paper reports on a recently proposed dynamic allocation technique that can be effectively adopted to handle the current saturations of the Poloidal Field coils with the eXtreme Shape Controller. The proposed approach allows to automatically relax the plasma shape regulation when the reference shape requires current levels out of the available ranges, finding in real-time an optimal trade-off between shape control precision and currents saturation avoidance. In this paper the results attained during preliminary analysis are presented, showing the advantage arising from the use of the dynamic allocator, versus the bare use of the eXtreme Shape Controller.

Fusion advanced studies torus (FAST) is a proposal for a satellite facility which can contribute the rapid exploitation of ITER and prepare ITER and DEMO regimes of operation, as well as exploiting innovative DEMO technology. FAST is a compact (R(0) = 1.82 m, a = 0.64 m, triangularity delta = 0.4) machine able to investigate non-linear dynamics effects of alpha particle behaviours in burning plasmas [1,2,5]. The project is based on a dominant 30 MW of ion cyclotron resonance heating (ICRH), 6 MW of lower hybrid (LH) and 4 MW of electron cyclotron resonance heating (ECRH). FAST operates at a wide range [3,4] of parameters, e.g., in high performance H-mode (B(T) up to 8.5T: I(p) up to 8 MA) as well as in advanced Tokamak operation (I(p) = 3 MA), and full non-inductive current scenario (I(p) = 2 MA). Helium gas at 30K is used for cooling the resistive copper magnets [6]. That allows for a pulse duration up to 170s. To limit the TF magnet ripple ferromagnetic insert have been introduced inside the vacuum vessel (VV). Ports have been designed to also accommodate up to 10 MW of negative neutral beam injection (NNBI). Tungsten (W) or liquid lithium (L-Li) have been chosen as the divertor plates material, and argon or neon as the injected impurities to mitigate the thermal loads. (C) 2009 Elsevier B.V. All rights reserved.

A new model-based shape controller (XSC, i.e., eXtreme Shape Controller) able to operate with high elongation and triangularity plasmas has been designed and implemented at JET in 2003. The use of the XSC needs a number of steps, which at present are not automated and therefore imply the involvement of several experts. To help the session leader in preparing an experiment, a number of software tools are needed. The paper describes the SW tools that are currently in the developing phase, and describes the new framework for the preparation of a JET experiment.

In this paper we present a dynamic model for the analysis of the vibrations of the vibrations of a planar articulated flexible boom to be used for tokamak in-vessel maintenance operations. The peculiarity of the mechanical structure of the boom enables us to consider separately the oscillations in the horizontal and vertical planes so that two separate models can be constructed for describing these phenomena. The results of simulations based on booms like that proposed for NET in-vessel operations are presented.

A reservoir regulation scheme for the control of deficiency yields is described in the paper. According to such scheme, at the end of each decade (=ten days) the release in the following decade is established on the basis of current storage, downstream users' requirements and forecast of future inflows. Such forecast is supplied by a mathematical predictor, namely a recursive relationship, which points out the most likely values of future inflows on the basis of current and recent inflow measurements. It is a goal-oriented predictor, in the sense that its parameters are evaluated through a procedure, which takes into account the objective of reservoir regulation (=control of downstream deficits). The regulation scheme is applied to a real case and the resulting sequence of yearly deficits is evaluated. Such deficits are compared with the ones obtained by introducing a different (=non-goal-oriented) predictor into the scheme.