1,721,341 research outputs found
Design for the upgrade of the Fast Sequence Control for Frascati Tokamak Upgrade
No full textIn ENEA Frascati research centre an experimental fusion machine called Frascati Tokamak Upgrade (FTU) is in operation since 1990. During the experimental activity, the automatic control and synchronization of many plants are required. The FTU control system [1] includes many sub-systems having different roles [2, 3]. In particular, a Fast Sequence Control (FSC) hardware is necessary to drive the tokamak power plants and to detect the errors in the fast control sequence during the plasma discharge. The FSC system was designed and realized in 1980s and is still in operation. Due to the obsolescence of some hardware components, a new project for the FSC Upgrade (FSCU) has been started. The project includes a new architecture based on up-to-date commercial hardware and dedicated firmware and software. In the present paper the architecture and the functions of the Fast Sequence Control - Upgrade system is described, along with the main differences between the two systems. © 2015 IEEE
IFMIF-DONES Central instrumentation and control systems: General overview
No full textPurpose of this work is to describe the Central Instrumentation and Control Systems for the International Fusion Materials Irradiation Facility-DEMO Oriented NEutron Source. A functional definition of the main systems is given, together with a general overview of the current status of the Central Instrumentation and Control Systems and the differences with respect to the corresponding system developed during the previous phases. The overall architecture of the Central Instrumentation and Control Systems (definitions, functions and requirements), the identification of subsystems and equipment, the control system design guidelines, and the Control Room requirements, are here described. Moreover, the Local Instrumentation and Control Subsystems is defined together with its relationship with the Central Instrumentation and Control Systems
Advances in the FTU collective Thomson scattering system
No full textThe new collective Thomson scattering diagnostic installed on the Frascati Tokamak Upgrade device started its first operations in 2014. The ongoing experiments investigate the presence of signals synchronous with rotating tearing mode islands, possibly due to parametric decay processes, and phenomena affecting electron cyclotron beam absorption or scattering measurements. The radiometric system, diagnostic layout, and data acquisition system were improved accordingly. The present status and near-term developments of the diagnostic are presented. © 2016 EURATOM
ITER CODAC core system at FTU: State of the art and new perspectives
No full textRecently the slow control of the MFG1 motor flywheel generator powering FTU toroidal magnet has been redesigned within the framework of the ITER CODAC I&C architecture [1] using the software package CODAC Core System (CCS). In this paper the progress made towards the final commissioning will be detailed, focusing on the system integration in the FTU control system supervisor through a software bridge and a multithreaded channel access interface to the Plant System Host, emphasizing the problems found so far and their solutions. The development and implementation of the alarm handler, the logging system and the data archiving system will also be illustrated, as well as the relevant monitoring and visualization interfaces developed on the Mini-CODAC node with the standard EPICS tools BEAST, BOY and BEAUTY. Furthermore, the tests run on FTU that finally led to a successful commissioning will be thoroughly discussed. Due to the satisfactory outcome of the project, and taking advantage of the release of the new CCS v 3.0 introducing the management of fast controllers, an account on a possible application of the CODAC ITER fast control architecture at FTU will also be given, taking the FTU real time feedback system as the first test case, to be further extended to newly implemented fast controllers. © 2013 Euratom-ENEA Association sulla Fusione
Basic concepts and implementation strategy of the plasma discharge command sequencer for FTU Tokamak
No full textThe plasma discharge phase of Frascati Tokamak Upgrade (FTU) is driven by the dedicated system FSC (Fast Sequence Control), which has been developed in order to send all the necessary commands to the different power plants, feeding the toroidal and poloidal coils during the plasma discharge, meanwhile controlling the correct outcome and recording all the events with time resolution of the order of 20 μs. In case of incorrect execution of the sequence the system is able to safely shutdown the plants and the plasma pulse. The FSC system has been recently upgraded porting it to an up to date off the shelf hardware platform, taking thus the opportunity to revise and update the basic concepts of the system and to increase its flexibility in view of possible applications to future fusion machines. The system is equipped with an integrated configurator and a custom sequence programming language allowing the user to program the sequences by linking the actuation times of the commands and of the state verifications each other or to global time parameters. A dedicated compilator performs the compilation of the sequence generating the binary files that are then loaded and implemented by the FSC hardware
The upgraded Collective Thomson Scattering diagnostics of FTU
No full textThe 140 GHz Collective Thomson Scattering (CTS) diagnostics installed on the Frascati Tokamak Upgrade (FTU) has been upgraded. The new system now is ready both to detect the thermal CTS radiation (for the first time with the probe frequency below the 1st harmonic electron cyclotron resonance) and to study the impact of possible parametric decay instability (PDI) processes on the received signals. The EC front-steering antenna and transmission system have been complemented with a receiving line that matches a quasi-optical line feeding the homodyne multi-channel radiometer. The scattering volume can be placed in a wide range of locations by means of fast poloidal and toroidal rotations of the two plasma-facing mirrors that have an up-down symmetry with respect to the equatorial plane of the torus. The data acquisition system has been improved adding a new digitizer, with a bandwidth of 5 GHz and a maximum sampling rate of 12.5 GS/s. The possibility of directly sampling and Fourier transforming the down-converted signals greatly improves the suitability of the new diagnostics to carry out thermal ion temperature measurements and to study the competing PDI processes whenever present. © 2015 EURATOM-ENEA. Published by Elsevier B.V. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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