The CEA contributions to the Broader Approach proje cts, IFERC, IFMIF [1] and JT-60SA [2] which included the deliveries of components and services ar now approaching completion. For IFERC, the supercomputer Helios, provided by CEA, will perform in the end 2016 its last runs after 5 years of operation with a very high availability and utiliza tion rate. For IFMIF, the CEA contributions includ e the deliveries and the commissioning of the prototy pe injector, of the beam diagnostics and beam control system which are now ready at Rokkasho and the prototype of the high energy SRF LINAC for which the manufacturing and delivery of most co mp nents will be completed end 2016. For JT60SA, the first TF coils have been produced, tested at the cold test facility at CEA Saclay and delivered to Naka. The JT-60SA cryogenic system is now commissioned at Naka. The five superconducting magnet power supplies, in charge of CEA, have performed successfully the factory acceptance tests. They were delivered at Naka mid-2 016 and their installation was completed midSeptember 2016. The first units of the mechanical s tructures of the JT-60SA magnetic field system, Outer Intercoil Structures and Gravity Supports wer e also delivered. This report synthetizes the achieved performances for all of these manufactured components and starts to draw the manufacturing and operation feedbacks gained by CEA in associatio n w th its industrial sub-contractors.

The construction, commissioning, and operation phases of the W7-X cryomagnetic test facility in CEA Saclay lasted ten years. The large diversity of equipments called, specialties involved and problems solved attest the expertise that was required to operate the test facility and test the coils. Nearly one hundred cryogenic tests were performed on the seventy W7-X coils, at a rate always increasing, using two cryostats each holding two coils.This paper presents the test facility and its operation first, the cryogenic difficulties that were confronted with their solutions, the electro-magnetic difficulties encountered along with corrective actions, and finally the instrumentation and data acquisition aspects. (C) 2011 Elsevier Ltd. All rights reserved.

In the framework of the Broader Approach Activities, the EU will deliver to Japan the 18 superconducting coils, which constitute the JT-60SA Toroidal field magnet. These 18 coils, manufactured by France and Italy, will be cold tested before shipping to Japan. For this purpose, the European Joint Undertaking for ITER, the Development of Fusion Energy ("Fusion for Energy", F4E) and the European Voluntary Contributors are collaborating to design and set-up a coil test facility (CTF) and to perform the acceptance test of the 18 JT-60SA Toroidal Field (TF) coils. The test facility is designed to test one coil at a time at nominal current and cryogenic temperature. The test of the first coil of each manufacturer includes a quench triggered by increasing the temperature. The project is presently in the detailed design phase. (C) 2011 Elsevier B.V. All rights reserved.

The recently developed 4C thermal-hydraulic code is validated here against experimental data from the cool-down of a non-planar coil of the Wendelstein 7-X stellarator from room temperature to the superconducting transition temperature of ∼10K, performed during the cold test of the full set of coils at the cryomagnetic test facility of CEA Saclay. The computed results, i.e., temperature and mass flow rate evolutions in different coil components (helium, casing, etc.) are shown to be in good agreement with the experimental data. The simulations also show that during the transient the hot spot temperature inside the coil can be up to ∼3–4K higher than what is seen on the casing surface.

Wendelstein 7-X (W7-X) is a superconducting stellarator under construction at the Max-Planck-Institute for Plasma Physics in Greifswald, Germany. The magnet system consists of 70 superconducting coils providing magnetic confinement-fields. Before assembly every coil had to pass an acceptance test at the French partner-institute CEA, Saclay, to examine its performance on leak tightness, high voltage strength, ampacity, and hydraulic flow at cryogenic conditions. The testing procedure was mandatory, as access for maintenance or repair after installation will not be viable. Testing followed a well specified routine including tests in warm conditions, during cool down, in cold conditions, during warm up and at last in warm conditions. Measurement was obtained firstly by the facility's instrumentation and secondly by the coil-casing's instrumentation. The received data was transmitted to different ASCII-files for each gauge. To record testing in detail, a meta-document was edited, which follows in its structure the routine mentioned above. Accordingly, the main distinctive functions of the coil during testing are recorded in so called test reports, while deviations from given thresholds and parameters are described in non conformity reports. During testing, organizational and technical challenges had to be mastered and the test program was regularly updated to meet technical improvements, manufacturing requirements and revised assembly schedules. This paper will present the acceptance test program, its development and the gained experiences.

The JT-60SA Toroidal Field coil design has been modified resulting in considerable material savings. The casing cooling loop is important during the beginning of cooldown. This study models the cooling phase foreseen for coil testing and coil operation. Data and experience gathered during the extensive cooling tests performed on 70 large W7-X coils at the CEA (Saclay) cryomagnetic test facility provide the basis knowledge to model and forecast the thermal behavior of other large magnets for thermonuclear fusion. Using coil material thermal properties, refrigeration limitations, procedure and control, a simple model of JT-60SA TF coil winding and casing cooling is proposed. Thermal gradients inside the coil are evaluated and discussed. The calculated cooldown time and the required cryogenic power will be used as design input for the coil testing facility.

An extensive acceptance test program for the Wendelstein 7-X (W7-X) confinement coils is presently being carried out in the CEA Saclay cryomagnetic test facility. Over half of the 50 non-planar coils and 20 planar coils have already been subject to a cool-down to liquid helium temperature, allowing current tests in the superconducting state.This paper presents a description of the cooling protocol observed at CEA. In-depth background information about the helium refrigeration technology limitations, the coil active cooling procedure and its control are given. The cryogenic power extraction is estimated through mass flow rate and enthalpy balance of the winding and casing helium circuits, which are derived from various coil and facility sensors.Coils geometry and material thermal properties are given, as well as a simple modelling of the coil cooling. The observed coil thermal behaviour can help to better understand the role of the casing cooling loop on the cooling inertia and on the total cooling time. Finally, the cooling down process is projected into the future operation of the W7-X stellarator under construction.More generally, data and experience gained from the cooling tests operated at the CEA Saclay cryomagnetic test facility provide practical knowledge to foresee the thermal behaviour and cryogenic challenges of other large magnets for thermonuclear fusion. (C) 2009 Elsevier B.V. All rights reserved.

The WENDELSTEIN 7-X (W7-X) superconducting stellarator experiment i.a. consists of 50 non-planar coils (npc) and 20 planar coils (pic). Before assembly the function of every coil is tested and examined at the French partner-institute CEA, Saclay. The testing follows a certain and constant routine laid out in a master-document (Overview); the main characteristical results are then recorded in appropriate reports. This presentation will point out the importance of good documentation. give an example of how it might be organized and show its respective needs of time and manpower. After testing some of the main data is collected in various tables and analysis-software for a first assessment and statistical analysis. The results will be presented as an example of a comparative firststep-database. (C) 2009 Published by Elsevier B.V.

WENDELSTEIN 7-X (W7-X) is a superconducting stellarator which uses 50 non-planar coils for the main confinement field and 20 planar coils for the magnetic configuration. All 70 coils are subject to an extensive test program after manufacturing and before assembly, realised at the cryomagnetic test facility at CEA Saclay. The tests are part of a well-advanced quality assurance plan attesting the specified coil performance. The test program is mainly divided in warm and cold tests. Various tests have to be performed such as visual inspections, hydraulic measurements, electrical tests and the check of sensors. The most elaborate test is the cryogenic temperature margin test using current up to 17.6kA including the quench or fast discharge test and the evaluation of the specified interlayer joint resistance. Up to now 75% of the coils have been tested and accepted. The last acceptance tests at CEA are scheduled to be performed beginning of 2009. The test program has been enhanced permanently in its course, due to further improvement as well as considering aspects of the time schedule. This paper will present a short description of the test program done at CEA, their aim and background.

Two short length samples have been prepared and tested in SULTAN to benchmark the performance of high current density, advanced Nb3Sn strands in the large cable-in-conduit conductors (CICC) for ITER. The cable pattern and jacket layout were identical to the Toroidal Field Model Coil Conductor (TFMC), tested in 1999. The four conductor sections used strands from OST, EAS, OKSC and OCSI respectively. The Cu:non-Cu ratio was 1 for three of the new strands, compared to 1.5 in the TFMC strand. The conductors with OST and OKSC strands had one Cu wire for two Nb3Sn strands, as in TFMC. In the EAS and OCSI conductors, all the 1080 strands in the cable were Nb3Sn. A dc test under relevant load conditions and a thermal-hydraulic campaign was carried out in SULTAN. The CICC performance was strongly degraded compared to the strand for all the four conductors. The current sharing temperature at the ITER TF operating conditions (j(op) = 286 A/mm(2), B = 11.15 T) was lower than requested by ITER.

In an effort to optimize superconductor cryogenics of large coils, dual channel cable-in-conduit conductors (CICC) have been designed. The qualitative and economic rationale of the conductor central channel is here justified but brings high complexity to the conductor cooling characteristics. Temperature gradients in the cable must be quantified to guarantee conductor temperature margin during coil operation under heat disturbance and set adequate inlet temperature. A simple one-dimensional thermal model, with neither fluid nor strand or jacket conduction, allows to better understand and quantify the steady state behavior of CICC central and annular channels. This thermohydraulic model with homogeneous central and annular temperatures and no jacket conduction is summarized with explicit thermal coupling equations. Local convection coefficients chosen proportional to friction factors lead to a model of global interchannel heat exchange coefficient serving the bithermal model. A first stationary experimental evaluation of the internal heat transfer coefficient using the interchannel heat exchange space constant at various heat loads and mass flow rates is illustrated on two full size samples tested at cryogenic temperatures. Annular heaters experiments with low distributed power achieve pertinent model correlation. Discrepancy between model and experimental data may be linked to the simplistic homogeneous annular temperature hypothesis, to the estimate of CICC mass flow distribution among channels, and to gravitational effects at high heat loads. Perturbation due to the thermosiphon generated between the two channels is considered since neither the experiments nor the expected applications are free of gravity.

Dual channel Cable-In-Conduit Conductors (CICC) provide low hydraulic resistance and faster central channel circulation, limiting superconductors temperature rise. The Poloidal Field Insert Sample (PFIS) was tested in the SULTAN facility to evaluate the thermal coupling between the CICC channels upon an experimental heat transfer coefficient assessment. Simple assumptions on the flow – homogeneous central and annular temperatures, no jacket conduction, no steel inertia and diffusivity – lead to a one-dimensional thermal model fully solved in its transient response to a Heavyside temperature evolution at the inlet, using a Laplace transformation. Transient temperature step data fitted with the analytical resolution provide heat transfer coefficients as a function of mass flow rate, compared to crude predictions. The transient measurements provided consistent measurements on the full range of mass flow rate in both vertical flow directions, whereas steady state homogenization characteristic length measures pursuing the same goal suffer from annular isothermal assumption. Recommendations are made for the thermohydraulic instrumentation of future conductor samples.

Convective heat transfer correlations in dual channel Cable In Conduit Conductor (CICC) are presented as functions of friction factor, and based on the Reynolds-Colburn analogy using the Stanton number. The developed thermohydraulic model determines helium temperatures in both channels, with the real geometrical spiral perforation. It is applied with pertinence to the Poloidal Field Full Size Joint Sample (PF-FSJS) and shows good agreement between the experimental measurements and the calculated temperatures, characterised by a 0.43 m space constant. The heat load applied in the bundle region induces density imbalance; the gravity effect in this vertical sample is evaluated and discussed.

This paper proposes to define a property language based on Message Sequence Charts (MSCs) to express requirements as properties on an SDL specification. To verify the dynamic behaviour of an SDL model, we have to check general properties such as deadlock, livelock and dynamic errors, but we also have to check that the SDL specification is correct with respect to its expected external requirements. For such a verification, we need a language to express these external requirements as properties on the SDL model, and this paper shows the adequacy of MSCs to define such a language. Detection of service interaction, which is a crucial problem for the introduction of new telecommunication services, is the guiding thread of this paper and demonstrates the adequacy of MSCs as a property language.