Search

Now that ITER is entering construction, many of its systems are in the final stages of design and analysis. Among them the 31 feeders, which will be supplied in-kind by the Chinese ITER partner. The feeders supply the electrical power and cryogens through the warm-cold barrier to the ITER superconducting magnet systems. They are complex systems with their independent cryostats and thermal shields, densely packed with many components, such as the current feeds, the cryogenic valves and High-Voltage (HV) instrumentation hardware. Some of the feeder components are particularly critical and have been designed with great care. Among them the High-Temperature Superconductor (HTS) current leads, designed for unprecedented currents, the 30 kV class, Paschen-hard HV insulation and the bus bar support system, designed to react the multi-ton Lorentz-forces from the bus bars at minimal heat load. This paper discusses the design challenges for these (and other) key components of the ITER magnet feeders. [ABSTRACT FROM PUBLISHER]

The mission of the JT-60SA Tokamak, which will be built in Japan, is to contribute to the early realization of fusion energy in support and supplement of the ITER program. The JT-60SA project is part of the broader approach for fusion energy. In 2008, due to a design change of the TF cross section, and following the redefinition of the global JT-60SA features, mechanical analyses were redone. The first 2D and 3D mechanical analyses were performed on the current TF design, providing useful information on the pros and cons of the new design. For the 2D analysis, the critical area of the inner leg cross section in the location of the equatorial plane was meshed to study the effect of in plane loads. The analysis includes checking the peak field applied to the conductors and the stress on each of the components of the winding pack cross section, in particular in the insulation which is a critical component. The stress in winding pack cross section is due to the accumulation of cool down strain, "in plane" Lorentz forces and to the quench pressure. Both magnetic and mechanical analyses are performed with the ANSYS V11.0 code. In this paper, we present the main steps of the 2D and 3D FEM calculations which were developed by CEA and used in the following analyses. Associated statements concerning possible TF design optimization with respect to cost, feasibility or risk are also presented. [ABSTRACT FROM AUTHOR]

In the framework of the JT-60SA project, included inside the Broader Approach agreement, EU is expected to provide to JA the totality of the toroidal field (TF) magnet system. It consists in 18 coils, evenly shared for in-kind procurement between France and Italy while the TF conductor providing is under the responsibility of Fusion for Energy. The conductor is a rectangular-shaped, NbTi-based, cable-in-conduit (CICC) and will be wound in double-pancake inside the TF casing. In the paper, the experimental approach of conductor design validation process and the associated analyses of conductor samples test campaign in the SULTAN facility are shown. A design and manufacture action on full-size SULTAN-type short samples for the TF conductor have been launched in 2007 to allow an early gathering of relevant information enabling to proceed onto the conductor design qualification process. A serie of two pre-prototypes was realized, based on a former conductor design which even if slightly different from the most up-to-date layout, includes all its important relevant features: square-shaped section, superconducting strands segregation with copper, no subwrapping. The samples are designed to allow comparative studies on shape influence (two types of sections) and on joint influence (presence or not of a bottom joint), and to provide a consolidated baseline for making decisions on conductor final design. A descriptive part of the samples manufacturing activity is included. The samples TFCS1 and TFJS1 were then characterized in the SULTAN facility (Villigen, CH) respectively in 2008 and 2009, experiencing DC tests, AC tests, mechanical cycling, and stability tests. The corresponding results and the associated analyses are shown and statements regarding the contribution of the present results to the assessment of the actual JT-60SA TF conductor design are also drawn. [ABSTRACT FROM AUTHOR]

The JT-60SA is a fusion experiment designed to contribute to the early realization of fusion energy, by providing support to the operation of ITER, by addressing key physics issues for ITER and DEMO and by investigating how best to optimize the operation of the next fusion power plants that will be built after ITER. It is a combined project of the JA-EU Satellite Tokamak Program under the Broader Approach (BA) Program and JAEA's Program for National Use, and it is to be built in Naka, Japan, using the infrastructure of the existing JT-60U experiment. This paper describes in detail the design of the JT-60SA Toroidal Field magnet and shows the strong points of each foreseen solution. Additional information about manufacturing procedures is given and technological issues are reported and critically analysed. [ABSTRACT FROM AUTHOR]

In this paper, we present an original method for the realization of hybrid photonic integrated circuits (PICs) based on ion-exchanged (IE) waveguides and III-V semiconductor materials. In our approach, we propose to bond thin semiconductor membranes at designated locations of the PIC where active functions are required. The advantage of very thin membranes is the possibility to keep the optical pathway defined by the IE waveguides even if the semiconductor refractive index is much higher than the glass refractive index. Modal analysis and beam propagation method simulations have been carried out in order to predict the modal structure of the propagated light into the membrane loaded IE waveguide and the transition from the IE waveguide itself through adiabatic tapers. [ABSTRACT FROM PUBLISHER]