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[en] This standard is applicable to coaxial high voltage connectors on nuclear instruments for dc applications up to 5000 volts and ac applications up to 3500 volts rms at 60 Hz. The connectors may also be used at higher frequencies provided the operating voltage is appropriately reduced
[en] One of the design features which yet offers interesting margins for performance optimization of cable-in-conduit conductors (CICCs), is their geometry. For relatively small size Nb3Sn CICCs, operating at high electromagnetic pressure, such as those for the EDIPO project, it has been experimentally shown that a design based on a rectangular layout with higher aspect ratio leads to the best performance, especially in terms of degradation with electromagnetic loads. To extend this analysis to larger size Nb3Sn CICCs, we manufactured and tested, in the SULTAN facility, an ITER toroidal field (TF) cable, inserted into a thick stainless steel tube and then compacted to a high aspect ratio rectangular shape. Besides establishing a new record in Nb3Sn CICC performances for ITER TF type cables, the very good test results confirmed that the conductor properties improve not only by lowering the void fraction and raising the cable twist pitch, as already shown during the ITER TFPRO and the EDIPO test campaigns, but also by the proper optimization of the conductor shape with respect to the electromagnetic force distribution. The sample manufacturing steps, along with the main test results, are presented here.
[en] This specification covers the requirements of superscreened cables. Part 1 covers general requirements and test methods. Part 2 covers data sheets setting out the electrical and mechanical requirements for each type of cable, together with engineering information. (U.K.)
[en] Field trials of a Fully Flexible Superconducting Cable (60 kV/1000 A, design Klaudy-Kabelmetal) including the necessary potheads were performed successfully in a real grid for the first time in the world during the years 1977-1980 at Arnstein (Austria). The cable met all electrotechnical and cryotechnical field and test conditions. The proposed cable is based on the corrugated tube principle (Wellmantel-technique of Kabelmetal) and offers an economically competitive and technically superior construction compared to presently favoured watercooled cables in the power range of 1 GW or even lower. This power rating is of interest already today for the electricity supply in densely populated areas and industrial centers
[en] The Phase I program examined the feasibility of insulating superconducting cable with a wrappable ceramic insulation. The goal is to lower the total magnet manufacturing cost by minimizing labor intensive fabrication and new capital expenditures, reducing risk, and increasing performance. Two new ceramic materials were identified which have the potential to meet existing performance requirements at a substantially lower cost. No chemical incompatibilities were observed between the wire and insulation. There results of the Phase I effort clearly demonstrated the feasibility of this innovate approach, and justify a Phase II program to continue the development effort
[en] An account is given of a research programme that has been going on for some years to study the mechanism by which electrical interference disturbs the correct operation of nucleonic instruments, particularly the wide-bandwidth equipment used with pulse counting types of measurement. One of the principal results of this work is the realization that most sources of interference cause currents to flow through the screening of the measuring installation and that it is this flow of current that causes signals to be generated that interfere with the measurement. Information is given on the characteristics of a variety of coaxial cables from this point of view, indicating which types are to be preferred. A discussion is also given of the influence of these factors on the mechanical design of electronic boxes. Techniques have been developed that, with the establishment of the relevant criteria, allow installations to be measured for their degree of susceptibility to electrical interference. Also the results of these measurements can be used to decide where to make changes to the installation to effect improvements. A large ''library'' of remedial measures is available and a few examples are given. (author)
[en] Opportunities for applications of high temperature superconducting (HTS) DC power cables for long distance power transmission in increasing the reliability of the electric power grid and to enable easier integration of distributed renewable sources into the grid are discussed. The gaps in the technology developments both in the superconducting cable designs and cryogenic systems as well as power electronic devices are identified. Various technology components in multi-terminal high voltage DC power transmission networks and the available options are discussed. The potential of ongoing efforts in the development of superconducting DC transmission systems is discussed. (paper)
[en] If the level of a liquid cryogen inadvertently falls below the top of a magnet winding, it may expose a segment of the conductor. Depending on the length of the uncooled segment and on how the matrix resistivity varies with temperature, zero, one, or two steady normal states may be possible. The stability of the various steady states, the conditions under which they appear, their energies of formation, and the voltages they produce are studied in this paper
[en] Besides the temperature and magnetic field, the strain and stress state of the superconducting Nb3Sn wires in multi-stage twisted cable-in-conduit conductors (CICCs), as applied in ITER or high field magnets, strongly influence their transport properties. For an accurate quantitative prediction of the performance and a proper understanding of the underlying phenomena, a detailed analysis of the strain distribution along all individual wires is required. For this, the thermal contraction of the different components and the huge electromagnetic forces imposing bending and contact deformation must be taken into account, following the complex strand pattern and mutual interaction by contacts from surrounding strands. In this paper, we describe a numerical model for a superconducting cable, which can simulate the strain and stress states of all single wires including interstrand contact force and associated deformation. The strands in the cable can be all similar (Nb3Sn/Cu) or with the inclusion of different strand materials for protection (Cu, Glidcop). The simulation results are essential for the analysis and conductor design optimization from cabling to final magnet operation conditions. Comparisons are presented concerning the influence of the sequential cable twist pitches and the inclusion of copper strands on the mechanical properties and thus on the eventual strain distribution in the Nb3Sn filaments when subjected to electromagnetic forces, axial force and twist moment. Recommendations are given for conductor design improvements.