Author: Zastrow, K-D.
Paper Title Page
WEPMU018 Real-time Protection of the "ITER-like Wall at JET" 1096
 
  • M.B. Jouve, C. Balorin
    Association EURATOM-CEA, St Paul Lez Durance, France
  • G. Arnoux, S. Devaux, D. Kinna, P.D. Thomas, K-D. Zastrow
    CCFE, Abingdon, Oxon, United Kingdom
  • P.J. Carvalho
    IPFN, Lisbon, Portugal
  • J. Veyret
    Sundance France, Matignon, France
 
  During the last JET tokamak shutdown a new ITER-Like Wall was installed using Tungsten and Beryllium materials. To ensure plasma facing component (PFC) integrity, the real-time protection of the wall has been upgraded through the project "Protection for the ITER-like Wall" (PIW). The choice has been made to work with 13 CCD robust analog cameras viewing the main areas of plasma wall interaction and to use regions of interest (ROI) for monitoring in real time the surface temperature of the PFCs. For each camera, ROIs will be set up pre-pulse and, during plasma operation, surface temperatures from these ROIs will be sent to the real time processing system for monitoring and eventually preventing damages on PFCs by modifying the plasma parameters. The video and the associated control system developed for this project is presented in this paper. The video is captured using PLEORA frame grabber and it is sent on GigE network to the real time processing system (RTPS) divided into a 'Real time processing unit' (RTPU), for surface temperature calculation, and the 'RTPU Host', for connection between RTPU and other systems. The RTPU design is based on commercial Xilinx Virtex5 FPGA boards with one board per camera and 2 boards per host. Programmed under Simulink using System generator blockset, the field programmable gate array (FPGA) can manage simultaneously up to 96 ROI defined pixel by pixel.  
poster icon Poster WEPMU018 [2.450 MB]  
 
MOPMU035 Shape Controller Upgrades for the JET ITER-like Wall 514
 
  • A. Neto, D. Alves, I.S. Carvalho
    IPFN, Lisbon, Portugal
  • G. De Tommasi, F. Maviglia
    CREATE, Napoli, Italy
  • R.C. Felton, P. McCullen
    EFDA-JET, Abingdon, Oxon, United Kingdom
  • P.J. Lomas, F. G. Rimini, A.V. Stephen, K-D. Zastrow
    CCFE, Culham, Abingdon, Oxon, United Kingdom
  • R. Vitelli
    Università di Roma II Tor Vergata, Roma, Italy
 
  Funding: This work was supported by the European Communities under the contract of Association between EURATOM/IST and was carried out within the framework of the European Fusion Development Agreement.
The upgrade of JET to a new all-metal wall will pose a set of new challenges regarding machine operation and protection. One of the key problems is that the present way of terminating a pulse, upon the detection of a problem, is limited to a predefined set of global responses, tailored to maximise the likelihood of a safe plasma landing. With the new wall, these might conflict with the requirement of avoiding localised heat fluxes in the wall components. As a consequence, the new system will be capable of dynamically adapting its response behaviour, according to the experimental conditions at the time of the stop request and during the termination itself. Also in the context of the new ITER-like wall, two further upgrades were designed to be implemented in the shape controller architecture. The first will allow safer operation of the machine and consists of a power-supply current limit avoidance scheme, which provides a trade-off between the desired plasma shape and the current distribution between the relevant actuators. The second is aimed at an optimised operation of the machine, enabling an earlier formation of a special magnetic configuration where the last plasma closed flux surface is not defined by a physical limiter. The upgraded shape controller system, besides providing the new functionality, is expected to continue to provide the first line of defence against erroneous plasma position and current requests. This paper presents the required architectural changes to the JET plasma shape controller system.
 
poster icon Poster MOPMU035 [2.518 MB]  
 
WEPMN014 The Software and Hardware Architectural Design of the Vessel Thermal Map Real-Time System in JET 905
 
  • D. Alves, A. Neto, D.F. Valcárcel
    IPFN, Lisbon, Portugal
  • G. Arnoux, P. Card, S. Devaux, R.C. Felton, A. Goodyear, D. Kinna, P.J. Lomas, P. McCullen, A.V. Stephen, K-D. Zastrow
    CCFE, Abingdon, Oxon, United Kingdom
  • S. Jachmich
    RMA, Brussels, Belgium
 
  The installation of ITER-relevant materials for the plasma facing components (PFCs) in the Joint European Torus (JET) is expected to have a strong impact on the operation and protection of the experiment. In particular, the use of all-beryllium tiles, which deteriorate at a substantially lower temperature than the formerly installed CFC tiles, imposes strict thermal restrictions on the PFCs during operation. Prompt and precise responses are therefore required whenever anomalous temperatures are detected. The new Vessel Thermal Map (VTM) real-time application collects the temperature measurements provided by dedicated pyrometers and Infra-Red (IR) cameras, groups them according to spatial location and probable offending heat source and raises alarms that will trigger appropriate protective responses. In the context of JET's global scheme for the protection of the new wall, the system is required to run on a 10 millisecond cycle communicating with other systems through the Real-Time Data Network (RTDN). In order to meet these requirements a Commercial Off-The-Shelf (COTS) solution has been adopted based on standard x86 multi-core technology, Linux and the Multi-threaded Application Real-Time executor (MARTe) software framework. This paper presents an overview of the system with particular technical focus on the configuration of its real-time capability and the benefits of the modular development approach and advanced tools provided by the MARTe framework.
See the Appendix of F. Romanelli et al., Proceedings of the 23rd IAEA Fusion Energy Conference 2010, Daejeon, Korea
 
poster icon Poster WEPMN014 [5.306 MB]  
 
FRAAULT04 Centralised Coordinated Control to Protect the JET ITER-like Wall. 1293
 
  • A.V. Stephen, G. Arnoux, T. Budd, P. Card, R.C. Felton, A. Goodyear, J. Harling, D. Kinna, P.J. Lomas, P. McCullen, P.D. Thomas, I.D. Young, K-D. Zastrow
    CCFE, Abingdon, Oxon, United Kingdom
  • D. Alves, D.F. Valcárcel
    IST, Lisboa, Portugal
  • S. Devaux
    MPI/IPP, Garching, Germany
  • S. Jachmich
    RMA, Brussels, Belgium
  • A. Neto
    IPFN, Lisbon, Portugal
 
  Funding: This work was carried out within the framework of the European Fusion Development Agreement. This work was also part-funded by the RCUK Energy Programme under grant EP/I501045.
The JET ITER-like wall project replaces the first wall carbon fibre composite tiles with beryllium and tungsten tiles which should have improved fuel retention characteristics but are less thermally robust. An enhanced protection system using new control and diagnostic systems has been designed which can modify the pre-planned experimental control to protect the new wall. Key design challenges were to extend the Level-1 supervisory control system to allow configurable responses to thermal problems to be defined without introducing excessive complexity, and to integrate the new functionality with existing control and protection systems efficiently and reliably. Alarms are generated by the vessel thermal map (VTM) system if infra-red camera measurements of tile temperatures are too high and by the plasma wall load system (WALLS) if component power limits are exceeded. The design introduces two new concepts: local protection, which inhibits individual heating components but allows the discharge to proceed, and stop responses, which allow highly configurable early termination of the pulse in the safest way for the plasma conditions and type of alarm. These are implemented via the new real-time protection system (RTPS), a centralised controller which responds to the VTM and WALLS alarms by providing override commands to the plasma shape, current, density and heating controllers. This paper describes the design and implementation of the RTPS system which is built with the Multithreaded Application Real-Time executor (MARTe) and will present results from initial operations.
 
slides icon Slides FRAAULT04 [2.276 MB]