•Lifus 6 plant was successfully realized and employed for Li erosion-corrosion tests.•Nitrogen concentration in Lithium was monitored and always kept below 30 wppm.•Up to 4000 h, Eurofer 97 and F82H ...showed a corrosion rate ≤0.2 μm/y.•Only a minor Chromium and Tungsten depletion was detected at the specimens surface.
In the framework of the IFMIF (International Fusion Materials Irradiation Facility) project, a lab scale plant named Lifus 6, designed and constructed in ENEA Brasimone Centre (Italy), has been employed for the evaluation of the resistance of Reduced Activation Ferritic-Martensitic (RAFM) steels to the erosion-corrosion mechanism exerted by flowing liquid Lithium. In this experimental campaign, Eurofer 97 and F82H specimens have been subjected to three different tests, defined by a Lithium temperature of 330 °C, a Nitrogen concentration in Lithium ≤30 wt ppm, a Lithium speed on the specimens surface of 15 m/s and by a duration respectively of 1222, 2000 and 4000 h. The assessment of the tests outcome has been made on the basis of the registered mass variation of each specimen, as well as its roughness alteration and its metallographic and compositional investigation. The analyses indicate the good resistance behavior of both the materials, which are characterized by corrosion rates <0.2 μm/year, very few and isolated corrosion items and only a small Chromium and Tungsten depletion in the alloy composition at the surface.
To operate advanced plasma scenario (long pulse with high stored energy) in present and future tokamak devices under safe operation conditions, the control requirements of the plasma control system ...(PCS) leads to the development of advanced feedback control and real time handling exceptions.
To develop these controllers and these exceptions handling strategies, a project aiming at setting up a flight simulator has started at CEA in 2009. Now, the new WEST (W Environment in Steady-state Tokamak) project deals with modifying Tore Supra into an ITER-like divertor tokamak. This upgrade impacts a lot of systems including Tore Supra PCS and is the opportunity to improve the current PCS architecture to implement the previous works and to fulfill the needs of modern tokamak operation.
This paper is dealing with the description of the architecture of WEST PCS. Firstly, the requirements will be presented including the needs of new concepts (segments configuration, alternative (or backup) scenario, …). Then, the conceptual design of the PCS will be described including the main components and their functions.
The third part will be dedicated to the proposal RT framework and to the technologies that we have to implement to reach the requirements.
The operation of present day tokamak and future machine like ITER is more and more demanding in terms of plasma control both for increasing plasma performance, stability and ensuring machine ...protection. Additionally saving experimental time by validating the pre-programmed plasma scenario through a simulator is also of major importance. These issues highlight the necessity to build new tools such as a generic multipurpose plasma discharge flight simulator. Such a project has been recently started at CEA and is based on the integrated tokamak modeling task force formalism and simulation platform. The paper reports on the present status of the project, reviewing in particular the needs for new tool development, the architecture of the generic multipurpose tokamak plasma discharge flight simulator, with the different software/hardware interfaces. A first test case of this tool in the “full simulation” modes and using the European simulation platform is discussed.
The feedback control of fusion experiments in tokamak devices is entering a new area driven by the increase of control requirements for obtaining burning plasmas under safe operation conditions. A ...project aiming at setting up a flight simulator for the development of advanced controllers has recently started at CEA. This simulator reuses most of the components of the European integrated tokamak modelling (ITM) simulation platform. Thus, it benefits from the development made by the task force and it will be able to offer a development platform for the new controllers of present day European tokamaks and future machines. The paper will report on the different software developments performed in order to set up a flexible and user friendly design and test of feedback control loops.
•Data Acquisition and Control Systems (DACS) upgrading of experimental plant for full size thermo hydraulic testing of nuclear subsystems.•DACS development using integrated hardware/software platform ...with graphical programming (LabVIEW).•Development of simplified models for real-time simulation.•Rapid prototyping with real time simulation of the complete plant.•Using the code developed for the real time simulator for the real plant DACS.
The EBBTF (European Breeding Blanket Test Facility) experimental plant is a key component for the development of the breeding blankets (TBMs test blanket modules, HCLL helium cooled lithium lead and HCPB helium cooled pebble bed types) used by ITER. EBBTF is an experimental plant which provides the double breeding/cooling loops (liquid metal and gas) required for HCLL testing. EBBTF is composed of four subsystems (TBM, IELLLO integrated European lead lithium loop, HE-FUS3 helium fusion loop, version 3 and helium compressor build by ATEKO) with dedicated control systems realized with hardware/software combinations covering 15 years (1995–2010) time span. At the end of 2010 we began to upgrade the HE-FUS3 data acquisition control systems (DACS) replacing the obsolete PLC Siemens S5 with National Instruments Compact FieldPoint and LabVIEW. The control room has been completely reorganized using high resolution monitors and workstations linked with standard Ethernet interfaces. The data acquisition, control, safety and SCADA software has been completely developed in ENEA using LabVIEW. In this paper we are going to discuss the technical difficulties and the solutions that we have used to accomplish the upgrade.
► Real-time event handling requires extended functionalities of pulse schedule editors and plasma control systems ► A new pulse schedule editor, conceived for parameterization of systematic ...off-normal event handling, is described ► A global, generic approach on off-normal event handling is highlighted ► The functional architecture of an off-normal event handling oriented plasma control system is discussed ► The main objects of the pulse schedule editor are the segment-descriptor object and the scenario-descriptor object.
Coping with unexpected events is an important issue of nuclear fusion experiments. The future machines, characterized by very long plasma discharges and actively cooled metallic plasma-facing components, will require a systematic intervention in real time, in order to maximize the performance and protect the investment. The real-time management of events will require extending the functionalities of the current pulse schedule editors with the possibility of using reference waveforms provided with acceptability margins and setting up advanced mitigation strategies and event countermeasures. With this purpose, a new pulse schedule editor, based on a time-segment approach for the preparation of experimental scenarios, is being conceived on Tore Supra, together with a new plasma control system. This paper will report on their conceptual design and give account of the preliminary results of a feasibility study currently under way in order to prepare a possible implementation on Tore Supra.
This article presents a new method for estimating the electron temperature of the Protosphera's screw pinch. The temperature radial profile is obtained by a self-consistent modeling of a 1D MHD ...equilibrium along with a 0D power balance of the plasma column, given measurements and estimates of the axial pinch plasma current, of the plasma rotational frequency and, at the equatorial plane, of the electron density radial profile, of the edge poloidal magnetic field, of the edge electron temperature and of the neutrals pressure in the vacuum vessel. The plasma is considered in equilibrium with its neutral phase and in constant rotation. A MATLAB code has been developed with the aim of estimating the MHD radial equilibrium profiles, the thermodynamic plasma state and the neutrals profile. The numerical estimates are compared with available experimental data showing a good agreement.
L’essai présente une brève rétrospective synoptique des deux concepts complémentaires de « décadence » et de « risorgimento », qui ont constitué la charpente essentielle du discours national italien ...presque jusqu’à nos jours. La première de ces notions trouve ses origines dans cette image de l’Italie comme un pays désespérément arriéré qui circule avec insistance dans les périodiques de la République des Lettres vers la fin du xvii e siècle ; la seconde se répand dans les dernières décennies du siècle suivant, pour parvenir à sa signification actuelle à la veille de 1848. L’analyse vise à montrer que les deux concepts, quoique destinés à acquérir une décisive connotation politique, enfoncent leurs racines dans un débat éminemment littéraire, inspiré par un patriotisme littéraire qui anticipe et trace le chemin aux revendications proprement institutionnelles.
L'essai présente une brève rétrospective synoptique des deux concepts complémentaires de « décadence » et de « risorgimento », qui ont constitué la charpente essentielle du discours national italien ...presque jusqu'à nos jours. La première de ces notions trouve ses origines dans cette image de l'Italie comme un pays désespérément arriéré qui circule avec insistance dans les périodiques de la République des Lettres vers la fin du XVIIᵉ siècle ; la seconde se répand dans les dernières décennies du siècle suivant, pour parvenir à sa signification actuelle à la veille de 1848. L'analyse vise à montrer que les deux concepts, quoique destinés à acquérir une décisive connotation politique, enfoncent leurs racines dans un débat éminemment littéraire, inspiré par un patriotisme littéraire qui anticipe et trace le chemin aux revendications proprement institutionnelles.
This essay is presenting a brief retrospect of the two complementary notions of "decadence” and "risorgimento”, which made up the framework of the Italian national discourse almost until today. The first notion originated from the picture, widely shared within the Republic of Letters in the late 17ᵗʰ Century, of Italy as a desperately backward country. The second notion had been spreading during the late 18ᵗʰ Century when it was given its current meaning on the eve of 1848. Both notions, although bound to take on a definitely political connotation, are shown on analysis to have sprung from an eminently literary dispute, inspired by a literary patriotism that paved the way to more properly institutional claims.
