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Garching bei München, Germany

Lacroix B.,French Atomic Energy Commission | Portafaix C.,French Atomic Energy Commission | Duchateau J.L.,French Atomic Energy Commission | Hertout P.,French Atomic Energy Commission | And 4 more authors.
IEEE Transactions on Applied Superconductivity

In the framework of the JT-60SA project, a parametric study was performed on the He mass flow rate cooling the Toroidal Field (TF) system. This mass flow is a crucial design parameter, since a high value is favorable regarding the temperature margin criterion, but requires more circulation power thus generating one of the main cryogenic loads. The study was led with the Tacos/Texto tool, based on Ansys (thermal) and Gandalf (thermohydraulics) codes. The impact of the TF conductor mass flow was analyzed, regarding on the one hand the temperature margin criterion, and on the other hand cryogenic aspects such as the TF magnet heat loads smoothing and the impact on the overall cryogenic system loads. Concerning the temperature margin criterion, the analysis showed that the foreseen nominal value of 4 g/s per conductor is appropriate for the studied reference scenario, while proposing a lower mass flow value in case of less demanding operation conditions, notably without or with low neutron heating. In such conditions, a TF mass flow limitation could bring an appreciable reduction of cryogenic loads, but shouldn't involve significant benefit regarding heat load smoothing. © 2011 IEEE. Source

Duchateau J.L.,French Atomic Energy Commission | Turck B.,French Atomic Energy Commission | Lacroix B.,French Atomic Energy Commission | Schwarz M.,Karlsruhe Institute of Technology | And 2 more authors.
IEEE Transactions on Applied Superconductivity

Under fast magnetic field variations, ac losses are deposited in a Cable in Conduit Conductor (CICC). The corresponding power losses are transferred to helium thanks to the high wetted perimeter of the conductor. The critical energy of the CICC can be expected to be proportional to the high volumetric heat capacity of helium and to the temperature margin. To confirm the expectations, stability tests under a transversal pulsed magnetic field were performed in the Sultan test facility on a prototype JT-60SA conductor sample. The shape of the magnetic field variation as a function of time is a truncated sinusoid. The experimental results are not totally in agreement with expected behavior on two particular points: the deposited energy in the conductor as a function of the pulsed field amplitude, measured by calorimetry, deviates from the expected quadratic behavior for coupling losses. The deviation is also increasingly dependent on the transport current at a given Sultan background magnetic field, the critical energies at low temperature margins are reduced in comparison with expected values. An explanation based on the saturation of parts of the cable is proposed. © 2011 IEEE. Source

Tsuchiya K.,Japan Atomic Energy Agency | Kizu K.,Japan Atomic Energy Agency | Murakami H.,Japan Atomic Energy Agency | Asakawa S.,Japan Atomic Energy Agency | And 3 more authors.
IEEE Transactions on Applied Superconductivity

PA (procurement arrangement) for poloidal field (PF) coil system, which consists of the central solenoid (CS) and the equilibrium field (EF) coils, was agreed between Japan and EU. During this activity, design of PF coils system was continued to be modified. For CS, material for the jacket of this conductor was changed into stainless steel (316LN) to make providing easier. In the modified material, maximum stress at the jacket was kept within the allowable limit. Accompanying this modification, the amount of pre-compress had to be re-estimated. Therefore, it was clarified that designs of pre-compression and tie plates need not to be major modification. For EF coils, positions and the number of turns were modified since the progress of the research for the plasma operations required in JT-60SA. Due to this optimization, total amount of superconducting material was reduced. The detail designs of PF coils were also performed to reduce the materials of supports and to evaluate the mechanical strength considering the various events. Thickness of clamp plate of the EF coil which received relatively small electromagnetic force was able to be reduced. Regarding the design of support legs with flexible plate, deformation of toroidal field (TF) coil was considered that should be included the evaluation of stress at this parts because this parts are directly attached on the TF coil case. Therefore, the revised designs of supports with sufficient mechanical strength were obtained for EF1 and EF4. © 2006 IEEE. Source

Portafaix C.,French Atomic Energy Commission | Barabaschi P.,JT 60SA European Home Team | Gauthier F.,French Atomic Energy Commission | Hertout P.,French Atomic Energy Commission | And 5 more authors.
IEEE Transactions on Applied Superconductivity

In the framework of the EU participation to JT-60SA project, a pseudo-3D thermo hydraulic tool was developed in order to address reliably the choice between multiple design options on the TF coils design. © 2006 IEEE. Source

Muzzi L.,ENEA | Corato V.,ENEA | De Marzi G.,ENEA | Di Zenobio A.,ENEA | And 8 more authors.
IEEE Transactions on Applied Superconductivity

In the framework of the JT-60SA design activities, EU home team has defined a reference layout for the Toroidal Field conductor: it is a slightly rectangular Cable-In-Conduit NbTi conductor, operating at 25.7 kA with a peak field of 5.65 T. ENEA has assigned LUVATA Fornaci di Barga the task to produce the strands and to perform cabling, whereas jacketing and compaction have been carried out in its own labs. The sample, successfully tested at the CRPP SULTAN facility, has been assembled in such a way as to avoid the bottom joint between the two legs, thus using a single conductor length (about 7 m). An ad-hoc developed solution to restrain the U-bent conductor section (where jacket is not present), consisting in a stainless steel He-leak tight box with an inner structure designed in order to completely block the cable, has been also developed and manufactured by ENEA, where the sample has been also assembled. Instrumentation installation and final assembly of the sample have been performed by the SULTAN team. The main aspects of the sample manufacturing and characterization are here presented and discussed. © 2006 IEEE. Source

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