Preliminary design of the control and data acquisition systems for the Neutral Beam Test Facility

The Neutral Beam Test Facility, which will be built in Padova, Italy, is aimed at developing the ITER heating neutral beam injector (HNB) and at testing and optimizing its operation up to nominal performance before installation on ITER. It requires the development of two independent experiments referred to as SPIDER (source for production of ions of deuterium extracted from Rf plasma) and MITICA (megavolt ITer injector & concept advancement). SPIDER will explore the full-size negative ion source for ITER, whereas MITICA will explore the full-size ITER neutral beam injector. Both experiments will be designed for long-pulse operation, up to 3600 s, as ITER itself. MITICA includes three functional components: the heating neutral beam injector plant system (HNB), which is the device under test; the auxiliary plant system (AUX), which includes all equipment to operate the HNB in the test facility (e.g. the local electric grid to feed the HNB power supplies), and MITICA supervisory system that is an electronics/informatics infrastructure to operate the facility. The paper introduces the requirements for the control and data acquisition systems of the experiments and proposes a preliminary design for both systems. SPIDER, which is preparatory to MITICA and will be developed on a shorter time scale, has no constraints coming from ITER CODAC, whereas MITICA includes the ITER neutral beam injector and therefore must be fully compatible with ITER CODAC.     

The J-TEXT CODAC system design and implementation

Inspired by the ITER COntrol, Data Access and Communication (CODAC) and ITER instrumentation and control system, J-TEXT tokamak has upgraded its control system with J-TEXT CODAC system. The J-TEXT CODAC system is based on Experimental Physics and Industrial Control System (EPICS). The J-TEXT CODAC system covers everything in the J-TEXT control system including both central and plant control systems, similar to the ITER I&C system. J-TEXT CODAC system is built around a single central control system called Central CODAC system. All the control functions including conventional control, interlock, safety and other common services are supervised by CCS. The J-TEXT CODAC system has been implemented and tested on J-TEXT. It not only tests some of the ideas in ITER CODAC in real life, but also explores the feasibility of new approaches that is unique in J-TEXT CODAC system.     

基于EPICS的J-TEXT CODAC系统

J-TEXT装置是华中科技大学恢复建造的中型托卡马克装置,已于2007年放电运行,其控制系统采用分布式结构,由多个子系统组成。为提高子系统集成、维护和更新的效率,并有效地管理各子系统、控制装置的运行状态及保障设备和人员安全,J-TEXT装置参考ITER CODAC的设计思路,结合J-TEXT装置的需求设计了J-TEXT CODAC系统。J-TEXT CODAC系统为装置各子系统提供统一的设计模型和相关设计标准,使用EPICS软件作为通讯中间层,设计了全局控制系统、时序和同步控制系统、联锁保护系统,并将原有控制系统改造、集成到J-TEXT CODAC系统中。目前该系统已部署在J-TEXT装置上,在2012年春季以来的多轮实验中运行良好。     

Influence of visual feedback on human task performance in ITER remote handling

In ITER, maintenance operations will be largely performed by remote handling (RH). Before ITER can be put into operation, safety regulations and licensing authorities require proof of maintainability for critical components. Part of the proof will come from using standard components and procedures. Additional verification and validation is based on simulation and hardware tests in 1:1 scale mockups.The Master Slave manipulator system (MS2) Benchmark Product was designed to implement a reference set of maintenance tasks representative for ITER remote handling. Experiments were performed with two versions of the Benchmark Product. In both experiments, the quality of visual feedback varied by exchanging direct view with indirect view (using video cameras) in order to measure and analyze its impact on human task performance.The first experiment showed that both experienced and novice RH operators perform a simple task significantly better with direct visual feedback than with camera feedback. A more complex task showed a large variation in results and could not be completed by many novice operators. Experienced operators commented on both the mechanical design and visual feedback. In a second experiment, a more elaborate task was tested on an improved Benchmark product. Again, the task was performed significantly faster with direct visual feedback than with camera feedback. In post-test interviews, operators indicated that they regarded the lack of 3D perception as the primary factor hindering their performance.     

FTU toroidal magnet power supply slow control using ITER CODAC Core System

FTU (Frascati Tokamak Upgrade) three-level slow control system has undergone several enhancements during its lifetime, involving essentially the supervisory and medium level, while the lower level is still mainly based on old Westinghouse Numalogic PLCs (Programmable Logic Controller). The legacy PLC controlling the toroidal magnet flywheel generator, named MFG1, is now being replaced with a more modern Siemens Simatic S7 PLC, because of its versatility an the ability to be integrated via standard networking protocol.The upgrade to this family of Siemens PLCs, which in the meantime has been selected as standard by ITER CODAC, has made MFG1 slow control an ideal candidate to deploy ITER CODAC software technologies and architecture to a running plant in an operating tokamak environment. A project has thus been started to port MFG1 control to ITER CODAC I&C architecture using the software package CODAC Core System to interface the PLC with the ITER standard systems for instrumentation and control, Plant System Host (PSH) and Mini-CODAC, developing dedicated HMI (Human–Machine Interface) and realizing the communication layer between MFG1 plant system and FTU supervisor.This paper will give a full account of the project and will report the results that have been obtained up to now, focusing also on the definite advantages provided by a distributed control architecture compared to the supervisor-dependent one still running at FTU, in view of future fusion devices.     

Development of the supervisory systems for the ITER diagnostic systems in JADA

In ITER, it is important how the CODAC system conducts many plant systems including diagnostic systems. In order to establish necessary communications between the diagnostics systems and the CODAC system, Japan domestic agency (JADA) has proposed the new concept of supervisory system for the diagnostic system based on our experiences in operating plasma diagnostic systems. The supervisory system manages operation sequences, current state and configuration parameters for the measurement. JADA designed the supervisory system satisfying the requirements from both CODAC system and diagnostic systems. In our design, the tool which converts operational steps described as flowcharts into the EPICS (experimental physics and industrial control system) records source codes is introduced. This tool will ensure reduction of the system designers’ efforts. We designed a communication protocol to configure measurement parameters and proposed configuration parameter validation function. We also analyzed the management of the central/local control mode for the diagnostic systems. The function which selects the adequate limit values and consistency check algorithms in accordance with the conditions of the diagnostics system is proposed. JADA will develop a prototype of the supervisory system and validate the design in 2013.     

Towards the conceptual design of the ITER real-time plasma control system

ITER will be the world's largest magnetic confinement tokamak fusion device and is currently under construction in southern France. The ITER Plasma Control System (PCS) is a fundamental component of the ITER Control, Data Access and Communication system (CODAC). It will control the evolution of all plasma parameters that are necessary to operate ITER throughout all phases of the discharge. The design and implementation of the PCS poses a number of unique challenges. The timescales of phenomena to be controlled spans three orders of magnitude, ranging from a few milliseconds to seconds. Novel control schemes, which have not been implemented at present-day machines need to be developed, and control schemes that are only done as demonstration experiments today will have to become routine. In addition, advances in computing technology and available physics models make the implementation of real-time or faster-than-real-time predictive calculations to forecast and subsequently to avoid disruptions or undesired plasma regimes feasible. This requires the PCS design to be adaptable in real-time to the results of these forecasting algorithms. A further novel feature is a sophisticated event handling system, which provides a means to deal with plasma related events (such as MHD instabilities or L-H transitions) or component failure. Finally, the schedule for design and implementation poses another challenge. The beginning of ITER operation will be in late 2020, but the conceptual design activity of the PCS has already commenced as required by the on-going development of diagnostics and actuators in the domestic agencies and the need for integration and testing. This activity is presently underway as a collaboration of international experts and the results will be published as a subsequent publication. In this paper, an overview about the main areas of intervention of the plasma control system will be given as well as a summary of the interfaces and the integration into ITER CODAC (networks, other applications, etc.). The limited amount of commissioning time foreseen for plasma control will make extensive testing and validation necessary. This should be done in an environment that is as close to the PCS version running the machine as possible. Furthermore, the integration with an Integrated Modeling Framework will lead to a versatile tool that can also be employed for pulse validation, control system development and testing as well as the development and validation of physics models. An overview of the requirements and possible structure of such an environment will also be presented.     

ITER prototype fast plant system controller

ITER CODAC Design identified the need for slow and fast control plant systems, based respectively on industrial automation technology with maximum sampling rates below 100 Hz, and on embedded technology with higher sampling rates and more stringent real-time requirements. The fast system is applicable to diagnostics and plant systems in closed-control loops whose cycle times are below 1 ms. Fast controllers will be dedicated industrial controllers with the ability to supervise other fast and/or slow controllers, interface to actuators and sensors and high performance networks (HPN).This contribution presents the engineering design of two prototypes of a fast plant system controller (FPSC), specialized for data acquisition, constrained by ITER technological choices. This prototyping activity contributes to the Plant Control Design Handbook (PCDH) effort of standardization, specifically regarding fast controller characteristics. The prototypes will be built using two different form factors, PXIe and ATCA, with the aim of comparing the implementations. The presented solution took into consideration channel density, synchronization, resolution, sampling rates and the needs for signal conditioning such as filtering and galvanic isolation. The integration of the two controllers in the standard CODAC environment is also presented and discussed. Both controllers contain an EPICS IOC providing the interface to the mini-CODAC which will be used for all testing activities. The alpha version of the FPSC is also presented.     

Architecture of SPIDER control and data acquisition system

The ITER Heating Neutral Beam injectors will be implemented in three steps: development of the ion source prototype, development of the full injector prototype, and, finally, construction of up to three ITER injectors. The first two steps will be carried out in the ITER neutral beam test facility under construction in Italy. The ion source prototype, referred to as SPIDER, which is currently in the development phase, is a complex experiment involving more than 20 plant units and operating with beam-on pulses lasting up to 1 h. As for control and data acquisition it requires fast and slow control (cycle time around 0.1 ms and 10 ms, respectively), synchronization (10 ns resolution), and data acquisition for about 1000 channels (analogue and images) with sampling frequencies up to tens of MS/s, data throughput up to 200 MB/s, and data storage volume of up to tens of TB/year. The paper describes the architecture of the SPIDER control and data acquisition system, discussing the SPIDER requirements and the ITER CODAC interfaces and specifications for plant system instrumentation and control.     

Design and application of an EPICS compatible slow plant system controller in J-TEXT tokamak

J-TEXT tokamak has recently implemented J-TEXT COntrol, Data Access and Communication (CODAC) system on the principle of ITER CODAC. The control network in J-TEXT CODAC system is based on Experimental Physics and Industrial Control System (EPICS). However, former slow plant system controllers in J-TEXT did not support EPICS. Therefore, J-TEXT has designed an EPICS compatible slow controller. And moreover, the slow controller also acts the role of Plant System Host (PSH), which helps non-EPICS controllers to keep working in J-TEXT CODAC system. The basic functionalities dealing with user defined tasks have been modularized into driver or plug-in modules, which are plug-and-play and configured with XML files according to specific control task. In this case, developers are able to implement various kinds of control tasks with these reusable modules, regardless of how the lower-lever functions are implemented, and mainly focusing on control algorithm. And it is possible to develop custom-built modules by themselves. This paper presents design of the slow controller. Some applications of the slow controller have been deployed in J-TEXT, and will be introduced in this paper.     

Software for fast cameras and image handling on MAST

The rapid progress in fast imaging gives new opportunities for fusion research. The data obtained by fast cameras play an important and ever-increasing role in analysis and understanding of plasma phenomena. The fast cameras produce a huge amount of data which creates considerable problems for acquisition, analysis, and storage.

We use a number of fast cameras on the Mega-Amp Spherical Tokamak (MAST). They cover several spectral ranges: broadband visible, infra-red and narrow band filtered for spectroscopic studies. These cameras are controlled by programs developed in-house. The programs provide full camera configuration and image acquisition in the MAST shot cycle.

Despite the great variety of image sources, all images should be stored in a single format. This simplifies development of data handling tools and hence the data analysis. A universal file format has been developed for MAST images which supports storage in both raw and compressed forms, using either lossless or lossy compression. A number of access and conversion routines have been developed for all languages used on MAST. Two movie-style display tools have been developed—Windows native and Qt based for Linux.

The camera control programs run as autonomous data acquisition units with full camera configuration set and stored locally. This allows easy porting of the code to other data acquisition systems. The software developed for MAST fast cameras has been adapted for several other tokamaks where it is in regular use.     

Evaluation of the ATCA fast controller standard for ITER diagnostics

ITER project's long time span and the nature of the instrumentation and control (I&C) procurement procedures for the Plant Systems require that the ITER Organization defines and follows well recognized standards which are used both by the industry and in physics experiments. The ITER I&C standards are defined in the Plant Control Design Handbook (PCDH) [1]. The ITER Organization has selected PCI Express and Ethernet for IO intercommunication to be used for plant system instrumentation for fast controllers. The decision on the usage of serialized I/O bus protocols is based on the impressive performance and the commercial availability. The form factors that will be supported by CODAC include PXIe, MicroTCA, and AdvancedTCA platforms. While the PXIe form factor is already well established for instrumentation purposes through the PXI Systems Alliance (www.pxisa.org), the AdvancedTCA and MicroTCA platforms which were originally targeted for the telecommunications market (www.picmg.org) are currently optimized and specified for instrumentation use through the xTCA extensions for physics [2]. The objective of this study is the evaluation of an integrated ATCA controller design using only commercial components.     

An integrated architecture for the ITER RH control system

The ITER remote handling (RH) system has been divided into 7 major equipment system procurements that deliver complete systems (operator interfaces, equipment controllers, and equipment) according to task oriented functional specifications. Each equipment system itself is an assembly of transporters, power manipulators, telemanipulators, vehicular systems, cameras, and tooling with a need for controllers and operator interfaces.From an operational perspective, the ITER RH systems are bound together by common control rooms, operations team, and maintenance team; and will need to achieve, to a varying degree, synchronization of operations, co-operation on tasks, hand-over of components, and sharing of data and resources. The separately procured RH systems must, therefore, be integrated to form a unified RH system for operation from the RH control rooms.The RH system will contain a heterogeneous mix of specially developed RH systems and off-the-shelf RH equipment and parts. The ITER Organization approach is to define a control system architecture that supports interoperable heterogeneous modules, and to specify a standard set of modules for each system to implement within this architecture. Compatibility with standard parts for selected modules is required to limit the complexity for operations and maintenance. A key requirement for integrating the control system modules is interoperability, and no module should have dependencies on the implementation details of other modules.The RH system is one of the ITER Plant systems that are integrated and coordinated through the hierarchical structure of the ITER CODAC system. It is distinguished from other Plant systems by the man-in-the-loop nature of RH operations and the need for control rooms at a level below the main control room. The RH control system architecture has been designed to also support the central monitoring and coordination of the RH activities.     

Overview of the ITER TBM Program

The objective of the ITER TBM Program is to provide the first experimental data on the performance of the breeding blankets in the integrated fusion nuclear environment. Such information is essential to design and predict the performance of DEMO and future fusion reactors. It foresees to test six mock-ups of breeding blankets, called Test Blanket Module (TBM), in three dedicated ITER equatorial ports from the beginning of the ITER operation. The TBM and its associated ancillary systems, including cooling system and tritium extraction system, forms the Test Blanket System (TBS) that will be fully integrated in the ITER machine and buildings. This paper describes the main features of the six TBSs that are presently planned for installation and operation in ITER, the main interfaces with other ITER systems and the main aspects of the TBM Program management.     

ITERDB—The Data Archiving System for ITER

For ITER, acquiring, managing and archiving its data is an essential task. ITER is foreseen to produce up to one terabyte of data per pulse and several petabytes of data per year. All the produced data needs to be stored and managed. The stored data is expected to serve the data access needs of ITER researchers located both on the ITER premises as well as worldwide during ITER's lifetime and beyond.ITERDB is a data management system being designed for centralized ITER data archival and data access. It is designed to manage and serve both unprocessed and processed data from the ITER plant systems and data analysis workflows.In this paper, we report the ITER Data Archiving System software requirements and priorities that have been identified by working with ITER staff and a large number of stakeholders. We will describe the design challenges and the proposed solutions. We will also present the current state of the ITERDB software architecture design.     

Neutronic analysis of ITER radial x-ray camera

The radial x-ray camera(RXC) is designed to measure the poloidal profile of plasma x-ray emission with high spatial and temporal resolution. The RXC diagnostic system consists of internal camera module and external camera module that view the core region and outer region through the vertical slots of the diagnostic first wall and diagnostics shield module of the equatorial port plug. To ensure the normal performance of the silicon photodiode array detectors of the cameras in the hard neutron irradiation environment in ITER tokamak, it is necessary to calculate neutron flux, radiation damage and the nuclear heating of the silicon photodiode array detectors and simulate the radiation maps of the range of RXC. This work estimated the nuclear environment of RXC based on Monte Carlo N-particle transport code, plasma scenarios of ITER tokamak and the RXC-integrated ITER CLITE model. The neutron flux of silicon photodiode array detectors and the lifetime of the silicon photodiode detector in the camera were calculated. The neutronic analysis results show that the shielding design has achieved the effect as expected and is able to guarantee the normal work of the detector during the ITER deuterium–deuterium phase without replacement, three detectors of the external camera can be operated during the whole deuterium–tritium phase without replacement.     

Event and Pulse Node Hardware Design for Nuclear Fusion Experiments

This article presents an event and pulse node hardware module (EPN) developed for use in control and data acquisition (CODAC) in current and upcoming long discharges nuclear fusion experiments. Its purpose is to allow real time event management and trigger distribution. The use of a mixture of digital signal processing and field programmable gate arrays, with fiber optic channels for event broadcast between CODAC nodes, and short length paths between the EPN and CODAC hardware, allows an effective and low latency communication path. This hardware will be integrated in the ISTTOK CODAC to allow long AC plasma discharges.     

The self-description data configuration model

ITER will consist of roughly 160 plant systems I&C delivered in kind which need to be integrated into the ITER control infrastructure. To make the integration of all these plant systems I&C, a smooth operation, the CODAC (Controls, Data Access & Communications) group release every year the core software environment which consists of many applications. In this paper we would like to describe what configuration data and how it is modeled in the version 2. The model is based on three views, the physical one which lists the components with their signals, the functional view which describes the control functions and variables required to implement them and the control view which links the two previous views. We use Hibernate as an ORM (Object Relational Mapping) framework with a PostgreSQL database and Spring as a framework to handle transactions.     

Real-time protection of in-vessel components in ASDEX Upgrade

A video real time safety system (VRT) for protection of in-vessel components was fully implemented in the machine control system (CODAC) from the 2007 experimental campaign on. The VRT is based on video cameras in contrast to infrared systems. The visible wavelength range has a smaller measurement range but is a factor 5–10 less sensitive against changes of the transmission of the optical system and the target emissivity compared to infrared systems. Up to 12 analog video channels with multiple regions of interest (ROI) are processed and monitored on each video stream. At present two safety algorithms, to detect the fraction of overheating in a ROI and hot spot detection, respectively, are implemented. The integral algorithm is preferentially used for probe or limiter protection, the hot spot algorithm for divertor protection. The VRT system is realized with ReadHawk real time operating system on a multi core Linux computer.