Koppe T.,Max Planck Institute for Plasma Physics (Greifswald) |
Cardella A.,Max Planck Institute for Plasma Physics (Greifswald) |
Missal B.,Max Planck Institute for Plasma Physics (Greifswald) |
Hein B.,Max Planck Institute for Plasma Physics (Greifswald) |
And 11 more authors.
Fusion Engineering and Design | Year: 2011
Wendelstein 7-X (W7-X) will be the world's largest superconducting helical advanced stellarator. This stellarator concept is deemed to be a desirable alternative for a future power plant like DEMO. The main advance of the static plasma is caused by the three dimensional shape of some of the main mechanical component inside the cryostat. The geometry of the plasma vessel is formed around the three dimensional shape of the plasma. The coils and their support structure are enclosed within the outer vessel. The space between the outer, the plasma vessel and the ports is called cryostat because the vacuum inside provides thermal insulation of the magnet system which is cooled down to 4 K. Due to the different thermal movements of both vessels and the support structure have to be supported separately. 10 cryo legs will bear the coil support structure. The plasma vessel supporting system is divided into two separate systems, allowing horizontal and vertical adjustments. This paper aims to give an overview of the main mechanical components of the cryostat. The authors delineate some disparate and special problems during the manufacturing of the components at the companies in Europe. It describes the current manufacturing and assembly. © 2011 Elsevier B.V. All Rights Reserved.
Zaccaria P.,Consorzio RFX |
Valente M.,Consorzio RFX |
Rigato W.,Consorzio RFX |
Dal Bello S.,Consorzio RFX |
And 9 more authors.
Fusion Engineering and Design | Year: 2015
The SPIDER experiment (Source for the Production of Ions of Deuterium Extracted from an RF plasma) aims to qualify and optimize the full size prototype of the negative ion source foreseen for MITICA (full size ITER injector prototype) and the ITER Heating and Current Drive Injectors. Both SPIDER and MITICA experiments are presently under construction at Consorzio RFX in Padova (I), with the financial support from IO (ITER Organization), Fusion for Energy, Italian research institutions and contributions from Japan and India Domestic Agencies. The vacuum vessel hosting the SPIDER in-vessel components (Beam Source and calorimeters) has been manufactured, assembled and tested during the last two years 2013-2014. The cylindrical vessel, about 6 m long and 4 m in diameter, is composed of two cylindrical modules and two torispherical lids at the ends. All the parts are made by AISI 304 L stainless steel. The possibility of opening/closing the vessel for monitoring, maintenance or modifications of internal components is guaranteed by bolted junctions and suitable movable support structures running on rails fixed to the building floor. A large number of ports, about one hundred, are present on the vessel walls for diagnostic and service purposes. The main working steps for construction and specific technological issues encountered and solved for production are presented in the paper. Assembly sequences and tests on site are furthermore described in detail, highlighting all the criteria and requirements for correct positioning and testing of performances. © 2015 Consorzio RFX. Published by Elsevier B.V. All rights reserved.
Michelato P.,National Institute of Nuclear Physics, Italy |
Monaco L.,National Institute of Nuclear Physics, Italy |
Sertore D.,National Institute of Nuclear Physics, Italy |
Pagani C.,University of Milan |
And 3 more authors.
IPAC 2013: Proceedings of the 4th International Particle Accelerator Conference | Year: 2013
Electron beam welding (EBW) is widely used in the construction of Niobium Superconducting RF cavities. The welding sequence of such a complex structure, foresees many welding operations. The welding parameters depend on many variables as the material thickness, but also on the component temperature before each weld. This paper presents a technique to measure the temperature of Nb components in vacuum during the EBW operation using an IR pyrometer placed outside the vacuum chamber through an appropriate vacuum viewport. With the current configuration the system can measure temperatures up to 350 °C in the vacuum conditions of the EBW vacuum chamber (10-5-10-6 mbar). The technique was used to optimize the time interval between each subsequent equatorial weld during Nb cavities production at Ettore Zanon, increasing the welding procedure reliability and decreasing the waiting time by control of the temperatures in the weld region. Moreover this technique can be generally used for in vacuum measurements of components from room temperature up to about 350 °C. Future developments are under way to make this technique compatible with UHV and increasing the measurement range. Copyright © 2013 by JACoW- cc Creative Commons Attribution 3.0 (CC-BY-3.0).