The French tokamak WEST supports the ITER design and operation. IRFM is designing a new Thomson scattering diagnostic to measure plasma density and temperature profiles. The diagnostic system ...consists of an endoscope inside a vacuum vessel, composed of actively cooled optical components. In order to validate and guarantee the diagnostic performances during normal operations, mechanical, thermal, hydraulic and vibratory behavior must be checked. Moreover, perpendicular displacement of the optical surface shall not be higher than 40 µm. Since this diagnostic operates in near infrared light, the temperature of all components must stay lower than 200 °C as not to bias the measurements. The differences in water temperature and pressure between the inlet and outlet of the diagnostic must be lower than 50 °C and 5.6 bar, respectively. The natural frequencies of the structure must be higher than 20 Hz and far enough from the frequency of external components. In this study, the worst radiative plasma scenario was chosen. The results of this study validate the accuracy of the measurements. Before manufacturing, electromagnetic disruption events must also be considered.
A new 3MW ECRH system at 105 GHz for WEST Delpech, Lena; Alberti, Stefano; Avramidis, Konstantinos ...
Fusion engineering and design,
January 2023, 2023-01-00, Letnik:
186
Journal Article
Recenzirano
Odprti dostop
The aim of the WEST experiments is to master long plasma pulses (1000s) and expose ITER-like tungsten wall to deposited heat fluxes up to 10 MW/m2. To increase the margin to reach the H-Mode and to ...control W-impurities in the plasma, the installation of an upgraded ECRH heating system, with a gyrotron performance of 1MW/1000s per unit, is planned in 2023. With the modifications of Tore Supra to WEST, simulations at a magnetic field B0∼3.7T and a central density ne0∼6 × 1019 m−3 show that the optimal frequency for central absorption is 105 GHz. For this purpose, a 105 GHz/1MW gyrotron (TH1511) has been designed at KIT in 2021, based on the technological design of the 140 GHz/1.5 MW (TH1507U) gyrotron for W7-X. Currently, three units are under fabrication at THALES. In the first phase of the project, some of the previous Tore Supra Electron Cyclotron (EC) system components will be re-installed and re-used whenever possible. This paper describes the studies performed to adapt the new ECRH system to 105 GHz and the status of the modifications necessary to re-start the system with a challenging schedule.
► The WEST programme is a unique opportunity to experience the industrial scale manufacture of tungsten plasma-facing components similar to the ITER divertor ones. ► In Tore Supra, it will bring ...important know how for actively cooled W divertor operation. ► This can be done by a reasonable modification of the Tore Supra tokamak. ► A fast implementation of the project would make this information available in due time. ► This allows a significant contribution to the W ITER divertor risk minimization in its manufacturing and operation phase.
The WEST programme consists in transforming the Tore Supra tokamak into an X point divertor device, while taking advantage of its long discharge capability. This is obtained by inserting in vessel coils to create the X point while adapting the in-vessel elements to this new geometry. This will allow the full tungsten divertor technology to be used on ITER to be tested in anticipation of its use on ITER under relevant heat loading conditions and pulse duration. The early manufacturing of a significant industrial series of ITER-similar W plasma-facing units will contribute to the ITER divertor manufacturing risk mitigation and to that associated with early W divertor plasma operation on ITER.
•VR technologies applied to Fusion enable better and faster understanding of integration issues.•Assembly problems are solved and validated on a numerical mockup.•Integration and accessibility issues ...can be identified in the earliest design on numerical mockup.•Problems are solved and validated on a physical mockup.•VR technologies are very helpful for assembly and maintenance operation simulations.
The WEST project (Tungsten (W) Environment in Steady state Tokamak) is an upgrade of the existing fusion machine, Tore Supra. The goal is to equip the tokamak with a fully cooled tungsten divertor and to transform the machine in a test platform open to all ITER partners.
The main assembly challenge of this project consists of an implementation of two magnet systems, called divertors, with an accuracy of 1mm. Indeed, each divertor has about 4m as diameter and has a heavy weight of 10 tons; also it introduces piece by piece in the original vessel through tight ports then assembled inside. To ensure a perfect fitting between these new components and a very constrained environment, it is necessary to use the latest CAD technologies available.
Beyond conventional CAD tools, the virtual reality (VR) room of the institute provides several useful tools. Thanks to the 185″ stereoscopic 3D screen and a force feedback arm linked to clash detection software developed by the CEA LIST, a new way to carry out design and assembly studies was performed. In order to improve VR results, metrology data (3D scan) enhance simulations. Therefore, it becomes possible to be aware of the real size of a component and future difficulties in assembling it.
At last, performance of such simulations is evaluated and compared to physical mockup in order to bring enhancement to the VR tools, before to be compared to the real operations on Tore Supra. The aim is to build a design tool that helps the designer since early stage of the design of complex systems, taking into consideration integration, assembly and maintenance aspects while reducing costs and schedule of a project.
•The manufacturing of the divertor structure and coils has been performed according to the technical specifications.•The scale one dummy coils have been tested, the last test (curing process ...validation) being scheduled to be done in September 2016.•The divertor in situ assembly has been carried out successfully.•The brazing process was carried out with an excellent repeatability.•The impregnation and curing phase of the divertor coils are scheduled to be done in November 2016.
In order to fully validate “ITER-like” actively water cooled tungsten plasma facing units, addressing the issues of long plasma discharges, an axisymmetric divertor structure has been studied and manufactured for the implementation in the WEST (W-Tungsten Environment in Steady state Tokamak) tokamak platform.
This assembly, called divertor structure and coils (4m diameter, 20t), is composed of two stainless steel casings containing an actively water cooled (up to 180°C, 4MPa) copper winding pack designed for a conductor current in the range of 12.5kA (up to 1000s). It must sustain harsh environmental conditions in terms of ultra-high vacuum, high temperatures and electrodynamic loads. One major difficulty is the assembly by induction brazing of individual bended conductor sectors inside the vacuum vessel and the consecutive sealing of the casings by TIG welding.
Therefor development activities have been carried out on a scale one dummy coil, such as brazing, assembly, thermal cycling and electrical insulation tests (5kV ground voltage). Whereas the brazing assembly technics and the conductor installation were validated without major difficulties, different technical solutions for the electrical insulation had to be tested. The chosen solution is a resin epoxy impregnated fiber glass fabric layered around the conductors followed by a polymerization procedure.
In parallel the manufacturing of divertor structure components started in the second half of 2013 with a total delivery at the end of 2015.
The paper will illustrate the technical developments which have been performed in order to fully validate the design. It concerns mainly the dummy coil and the complex conductor installation procedure assisted by virtual reality tools. The manufacturing methods proposed by industry in order to fulfil the technical requirements will be also addressed. Finally the processes and associated tools used in order to implement this large component inside the WEST vacuum vessel will be detailed.
Design and manufacturing of WEST Baffle Batal, Tristan; Firdaouss, Mehdi; Richou, Marianne ...
Fusion engineering and design,
10/2015, Letnik:
98-99
Journal Article
Recenzirano
•Disruption's torque in the PFC was simulated thanks to ANSYS.•The ANSYS thermal results comply with WEST project requirements.•The cycling analysis complies with WEST project requirements.•316L ...components comply with A level RCC-MRx criteria.
The Tore Supra tokamak is being transformed in an X-point divertor fusion device in the frame of the WEST project, launched in support to the Iter tungsten divertor strategy. The WEST Baffle aims to evacuate particles by creating a toroidal pumping throat. It also protects the lower divertor cooling pipes and the passive stabilization plate from heat fluxes. The Baffle is made of actively cooled plasma facing components (PFCs), with underneath a passive stabilization plate and a support beam. The Baffle design is presented in a first part. In a second time the different ANSYS simulations are described: electromagnetic, thermal and mechanical results are presented. The design choices are justified for the different results obtained thanks to the simulation. In a final part, some aspects of the PFC manufacturing are presented.
•The divertor PFU integration has been studied regarding existing environment.•Magnetic, electric, thermal, hydraulic, mechanical loads and assembly are considered.
In the context of the Tokamak ...Tore-Supra evolution, the CEA aims at transforming it into a test bench for ITER actively cooled tungsten (ACW) plasma facing components (PFC). This project named WEST (Tungsten Environment in Steady state Tokamak) is especially focused on the divertor target. The modification of the machine, by adding two axisymmetric divertors will make feasible an H-mode with an X-point close to the lower divertor. This environment will allow exposing the divertor ACW components up to 20MW/m2 heat flux during long pulse. These specifications are well suited to test the ITER-like ACW target elements, respecting the ITER design.
One challenge in such machine evolution is to integrate components in an existing vacuum vessel in order to obtain the best achievable performance. This paper deals with the design integration of ITER ACW target elements into the WEST environment considering magnetic, electric, thermal and mechanical loads. The feasibility of installation and maintenance has to be strongly considered as these PFC could be replaced several times. The ports size allows entering a 30° sector of pre-installed tungsten targets which will be plugged as quickly and easily as possible. The main feature of steady state operation is the active cooling, which leads to have many embedded cooling channels and bulky pipes on the PFC module including many connections and sealings between vacuum and water channels. The 30° sector design is now finalized regarding the ITER ACW elements specifications. No major modifications are expected.
•The mechanical design and integration of the divertor structure have been performed.•The design of the casing and the winding-pack has been optimized.•The coil assembly process has been ...assessed.•The realization of a coil mock-up scale one is scheduled.
In order to fully validate “ITER-like” actively water cooled tungsten plasma facing units, the implementation of an axisymmetric divertor structure in the Tokamak Tore-Supra has been studied. With this major upgrade, the so-called WEST (Tungsten Environment in Steady state Tokamak), Tore-Supra will be able to address the issues of long plasma discharges using a tungsten divertor based on monoblock targets.
The divertor structure and coils assembly are made up of two stainless steel casings containing a copper winding pack cooled by a pressurized hot water circuit (up to 180°C, 4MPa) in which a total divertor current of up to 16×13kA is circulating in steady state. The conductor is electrically insulated and wedged inside the casing in order to be mechanically protected.
The divertor which is designed to perform steady state plasma operation (up to 1000s), must sustain harsh environmental conditions in terms of ultra light vacuum conditions, electromagnetical loads and electrical insulation (5kV ground voltage) under high temperature (180°C).
Therefore, a feasibility study of such a complex structure has been performed. It implied activities on a scale one dummy coil, such as installation, assembly issues and representative tests (electric, thermal and hydraulic).
The manufacturing of the divertor structure, which is a large assembly of 4-m diameter representing a total weight of around 20tonnes, started in the second half of 2013 and is expected to be delivered by the end of 2014.
The paper will illustrate the technical developments and tests performed during 2013 and beginning of 2014 in order to fully validate the design concept before the industrial phase. The manufacturing methods proposed by the contractor in order to fulfil the technical requirements will be also addressed.
•A design and configuration management platform is under development for managing fusion components lifecycle at CEA.•Design platform ensures an efficient sharing of the data and provides connections ...between the different software and databases involved in fusion components design.•Design platform rollout on WEST project is ongoing as part of change control and configuration management implementation.
This paper presents the technical solutions and methodologies that are used and under development for managing the design lifecycle of the WEST project (W – for tungsten – Environment in Steady-state Tokamak, upgrade of Tore Supra's with actively cooled tungsten plasma facing components) fusion components and explains the interfaces that are implemented or in construction to connect together the different tools like documents management system, CAD modeler, or simulation codes around the data management backbone. It describes the methodologies used on the WEST project to optimize the design process by managing the engineering data workflow and ensuring the consistency between the different 3D representations for design or analysis as well as the specification or interfaces documents. Finally it explains how this platform contributes to reach the project targets in terms of performance, cost and schedule.
In the context of ITER, CEA/IRFM has participated to the design and integration of several components in the Equatorial Port plug region. Particularly, in the framework of the grant ...F4E-2008-GRT-09-PNS-TBM, CEA/IRFM has contributed to the test blanket module system (TBS) design and robot access feasibility study in the Port Cell.
Simulations of the maintenance procedure were studied and fully integrated to the design process, enabling to provide space reservation for human and robotic access. For this mean, CEA/IRFM has used a CEA LIST Virtual Reality simulation software directly integrated to the Solidworks CAD software. The feasibility to connect/dis-connect the pipes in front of the Bioshield by a set of potential standard industrial arms was demonstrated.
Aiming to give more realism to maintenance scenario and CAD models, CEA IRFM has decided to build a Virtual Reality platform in the institute, integrated to the design office. With the expertise of CEA LIST, this platform aims to provide the nearest possible links between design and remote handling needs.
This paper presents the outcome of the robot access study and discusses about the Virtual Reality tools that are being developed for these applications.
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