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The ITER Central Solenoid (CS) is one of the critical elements of the machine. The CS conductor went through an intense optimization and qualification program, which included characterization of the strands, a conductor straight short sample testing in the SULTAN facility at the Swiss Plasma Center (SPC), Villigen, Switzerland, and a single-layer CS Insert coil recently tested in the Central Solenoid Model Coil (CSMC) facility in QST-Naka, Japan. We obtained valuable data in a wide range of the parameters (current, magnetic field, temperature, and strain), which allowed a credible characterization of the CS conductor in different conditions. Using this characterization, we will make a projection to the performance of the CS in the ITER reference scenario. [ABSTRACT FROM AUTHOR]

The Central Solenoid (CS), a key component of the ITER Magnet system, using a 45 kA Nb 3 Sn conductor, includes six identical coils, called modules, to form a solenoid, enclosed inside a structure providing vertical pre-compression and mechanical support. Procurement of the components of the ITER CS is the responsibility of US ITER, the US Domestic Agency (USDA), while the assembly of these components will be carried out by the ITER Organization (IO). Procurement of all the coil modules was awarded in 2011 to General Atomics, while procurement of the structure is split among several manufacturers, using existing equipment, sometimes among the largest ones in the world. Assembly of the ITER CS will require a dedicated area in the ITER Assembly Hall, conventional tooling and special tooling. US ITER is in charge of the procurement of special tooling, while IO is responsible for the procurement of the conventional ones. A detailed assembly procedure is under development at US ITER, in close collaboration with IO and with the support of CEA. Procurement of the special Assembly Tooling is carried out by US ITER and the main part of the first item, the Assembly Platform, was delivered to IO in 2017. [ABSTRACT FROM AUTHOR]

• Electrical performance of ITER CS prototype joints. • Detailed destructive examination of ITER prototype joints: twin – box and coaxial. • Explanation of the difference in performance based on the destructive examinations. The ITER Magnet System will be the largest and most challenging integrated superconducting magnet system ever built. For the Central Solenoid (CS), cable – in – conduit - conductors (CICCs) of nearly one kilometre length are produced, but still, it will be necessary to connect several lengths together to wind the gigantic 110 tonnes coils. The creation of these superconducting joints is one of the most delicate parts of the assembly. There are three types of ITER CS joints: splice joints, coaxial joints and twin – box joints. US ITER, the ITER Domestic Agency of the USA produced a prototype containing all three types of joints. The goal is to test the performance of the joints in the SULTAN facility of the Swiss Plasma Center (SPC), capable of reproducing close – to – service conditions: high magnetic field (up to 11 T background field), high current (up to 100 kA) and high mass flow rate of supercritical helium for cooling. The paper describes the results of a comprehensive examination campaign aimed at understanding the relation between fabrication and performance of the CS prototype joints. The test campaign combines advanced image analysis for the assessment of the void fraction of the conductors with Scanning Electron Microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) to evaluate the quality of the contact between the strands and the sleeve / sole of the joints. [ABSTRACT FROM AUTHOR]

Abstract: Fusion research in the United States is sponsored by the Department of Energy''s Office of Fusion Energy Sciences (OFES). The OFES sponsors a wide range of programs to advance fusion science, fusion technology, and basic plasma science. Most experimental devices in the US fusion program are constructed using conventional technologies; however, a small portion of the fusion research program is directed towards large scale commercial power generation, which typically relies on superconductor technology to facilitate steady-state operation with high fusion power gain, Q. The superconductor portion of the US fusion research program is limited to a small number of laboratories including the Plasma Science and Fusion Center at MIT, Lawrence Livermore National Laboratory (LLNL), and the Applied Superconductivity Center at University of Wisconsin, Madison. Although Brookhaven National Laboratory (BNL) and Lawrence Berkeley National Laboratory (LBNL) are primarily sponsored by the US''s High Energy Physics program, both have made significant contributions to advance the superconductor technology needed for the US fusion program. This paper summarizes recent superconductor activities in the US fusion program. [Copyright &y& Elsevier]