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Cable-in-conduit conductor (CICC), one of the most promising conductors for manufacturing magnets in magnetic confinement fusion devices, has attracted lots of attention. In the production of CICC, porosity control is necessary for its stability. The porosity control is usually realized by the diameter-reducing process, which would also lead to indentation damages to the elements of CICC-superconducting wires. In this article, systematic research of indentation damages was carried out on the next generation of high-temperature superconducting materials–Bi-2212 wires. The results indicate that the current carrying capacity of the indentation-damaged wire would first keep steady and then show exponential decline with the increase of indentation depth. The wires subjected to pre-overpressure (pre-OP) treatment exhibit slightly improved resistance against indentation damage at shallow indentation depths. However, their critical current (I c) deteriorates more rapidly at greater indentation depths when compared to wires that have not undergone the per-OP process. The following structural characterization analyzed the reasons for the property changes with the help of scanning electron microscopy, energy dispersive x-ray spectroscopy, computed tomography, and hardness tester. Misalignment between the Bi-2212 grains and shaped filaments was found in the indentation-damaged wires, with which the degradation in I c of the wires and the differences in properties of the two kinds of wires were further discussed. [ABSTRACT FROM AUTHOR]

Bi-2212 is one of the most hopeful superconducting material by virtue of its excellent irreversible field and isotropic electromagnetic characteristic. We developed Bi-2212 insert coil for the sake of testing the uniform performance of the round wire (RW). Some important explorations were made including the preliminary test of coil insulation, sealing and heat treatment. In the end, the insert coil achieved a critical performance of 130 A at 12 T and 4.2 K. The experiment results indicated that Bi-2212 RW had met the future application. [ABSTRACT FROM AUTHOR]

The China Fusion Engineering Test Reactor is a new tokamak device whose magnet system includes toroidal field (TF), central solenoid (CS), and poloidal field (PF) coils which are made up of cable-in-conduit conductor (CICC). The maximum field of CS and TF will reach around 15 T, which is much higher than that of present reactors. In this case, the high-temperature superconducting material Bi-2212 is considered as one potential magnet material for CICC because it has an outstanding conductor-carrying capacity at 4.2 K in magnetic field, especially for that with high-pressure heat treatment. However, Bi-2212 phase is a ceramic structure, which is sensitive to strain. The mechanical property is important for its application. In this paper, the axial tensile measurements on Bi-2212 round wires with different heat treatments were performed at room temperature, 77 K and 4.2 K, respectively. It was found that the wires with high pressure heat treatment had higher mechanical strength than that with normal pressure. The compared results were given, and SEM of cross sections for tested samples was also made and analyzed. [ABSTRACT FROM PUBLISHER]

China fusion engineering test reactor (CFETR) is a new tokamak device, whose magnet system includes the toroidal field, central solenoid (CS), and poloidal field coils. In order to develop the manufacturing process for the full-size CS coil, the CS model coil (CSMC) project was launched first. The cable-in-conduit conductor used for CFETR CSMC refers to ITER CS conductor with the same short twist pitch cable pattern. They have the similar layout. In order to qualify the manufacturing process and performance of conductor, two short sample conductors with two different jacket materials (316LN and high-Mn steel) were manufactured. The conductors were tested at Swiss Plasma Center successfully. In future, the CSMC will be tested at the Institute of Plasma Physics, CAS (ASIPP). In this paper, the manufacturing processes for conductor are described in detail. The strand damage analysis and conductor performance were also discussed. [ABSTRACT FROM PUBLISHER]

The CFETR, “China Fusion Engineering Test Reactor,” is a new tokamak device. Its magnet system includes the toroidal field (TF), central solenoid (CS), and poloidal field coils. The main goal of this study is to build a fusion engineering tokamak reactor with fusion power of 50–200 MW and self-sufficiency by blanket. The maximum field of CS and TF will get around 15 T, which is much higher than that of other reactors. New materials could be used to develop the magnet technology for the next generation of fusion reactors. Bi2Sr2CaCu2Ox is considered as a potential material for the superconducting magnets. An R&D activity is running at ASIPP for the feasibility demonstration of cable-in-conduit conductor based on the Bi2212 wire. One subsize conductor cabled with 42 wires was designed and manufactured. In this paper, the manufacturing procedures and first test results of Bi-2212 conductor samples are described in details, including wire specifications, cabling and compaction process, conductor heat treatment, as well as test results on ac loss and critical current. [ABSTRACT FROM PUBLISHER]