The Experts below are selected from a list of 234 Experts worldwide ranked by ideXlab platform
Pierluigi Bruzzone - One of the best experts on this subject based on the ideXlab platform.
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A Prototype Conductor by React&WIND Method for the EUROfusion DEMO TF Coils
IEEE Transactions on Applied Superconductivity, 2018Co-Authors: Pierluigi Bruzzone, D. Uglietti, Rainer Wesche, Kamil Sedlak, Xabier Sarasola, Boris Stepanov, Luigi Muzzi, Antonio Della CorteAbstract:The ReactW –0.30%. After the baseline of the DEMO device was updated in 2015, the new requirements led to an updated conductor design, for 63 kA at 12.2 T. The manufacturing experience of the first prototype, named RW1, is exploited in a second short-length prototype conductor, named RW2, assembled and tested in 2017: The conductor aspect ratio is reduced, and the segregated copper wires are replaced by a solid block of mixed matrix stabilizer. Although designed for the TF coils, with dc operation, the moderate ac loss of the Flat Cable makes the RW2 a good candidate also for the central solenoid conductor. The Nb3Sn strand for RW2 is supplied by WST (PRC), and the Flat Cable is made at TRATOS (Italy). The rationale of the design, the conductor manufacture, the sample assembly, and the test results in SULTAN are reported.
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High temperature superconductors for fusion at the Swiss Plasma Center
Nuclear Fusion, 2017Co-Authors: Pierluigi Bruzzone, D. Uglietti, Rainer Wesche, Nikolay BykovskyAbstract:High temperature superconductors (HTS) may become in future an option for the superconducting magnets of commercial fusion plants. At the Swiss Plasma Center (SPC) the R&D activity toward HTS high current, high field Cables suitable for fusion magnets started in 2012 and led in 2015 to the assembly of the first 60 kA, 12 T prototype conductor. The Cable concept developed at the SPC is based on the principle of 'soldered, twisted stacks' of REBCO tapes. The required number of stacks is assembled in a cored Flat Cable, cooled by forced flow of supercritical helium. The sample environment of the test facility at SPC has been upgraded with a HTS adapter and a counter-flow heat exchanger to allow testing the HTS sample in a broader range of temperature (4.5 K–50 K) using the existing, NbTi based superconducting transformer and the closed loop refrigerator.
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Test of 60 kA coated conductor Cable prototypes for fusion magnets
Superconductor Science and Technology, 2015Co-Authors: D. Uglietti, Nikolay Bykovsky, Rainer Wesche, Kamil Sedlak, Boris Stepanov, Pierluigi BruzzoneAbstract:Coated conductors could be promising materials for the fabrication of the large magnet systems of future fusion devices. Two prototype conductors (Flat Cables in steel conduits), each about 2 m long, were manufactured using coated conductor tapes (4 mm wide) from Super Power and SuperOx, with a total tape length of 1.6 km. Each Flat Cable is assembled from 20 strands, each strand consisting of a stack of 16 tapes surrounded by two half circular copper profiles, twisted and soldered. The tapes were measured at 12 T and 4.2 K and the results of the measurements were used for the assessment of the conductor electromagnetic properties at low temperature and high field. The two conductors were assembled together in a sample that was tested in the European Dipole (EDIPO) facility. The current sharing temperatures of the two conductors were measured at background fields from 8 T up to 12 T and for currents from 30 kA up to 70 kA: the measured values are within a few percent of the values expected from the measurements on tapes (short samples). After electromagnetic cycling, T-cs at 12 T and 50 kA decreased from about 12 K to 11 K (about 10%), corresponding to less than 3% of I-c.
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Pre-conceptual studies and R&D for DEMO superconducting magnets
Fusion Engineering and Design, 2014Co-Authors: Pierluigi BruzzoneAbstract:The DEMO plant will demonstrate by mid century the feasibility of electric power generation by nuclear fusion. Since 2011, conceptual design studies are coordinated by the EFDA Power Plant Physics and Technology (PPPT) Division, with the aim of identifying requirements, propose design approaches and start RD for the magnet system of DEMO. The input and generic boundary conditions are given by the system codes: the major radius of the tokamak is about 9m. The proposed operating current at 13.6T peak field is 82 kA, placing the DEMO TF conductor at substantially higher performance compared to ITER TF (68 kA/11.5 T). The innovative winding layout is a graded, layer wound with Nb3Sn/NbTi hybridization, aiming at minimizing the size and the cost of the superconductor. Two options are considered for the Nb3Sn conductor: one a "windr" Cable-in-conduit (CICC) with reduced void fraction and rectangular shape. The other conductor is a "reactw" Flat Cable with copper segregation and thick steel conduit assembled by longitudinal weld. The conductor designs were first drafted in 2012 and updated in 2013 based on a first round of assessments, which includes electromagnetic, thermal-hydraulic and mechanical analysis. The manufacture of full size prototype conductors is planned in 2014. The technical requirement of the DEMO superconducting magnets is highlighted in comparison to ITER and other fusion devices. The large size of the DEMO tokamak is the main challenge for the demonstration of the feasibility of power generation by fusion. Together with the technical issues, the cost of the superconducting magnets will be eventually the crucial aspect to promote the establishment of nuclear fusion as a primary energy source in the coming centuries. (C) 2014 Elsevier B.V. All rights reserved.
D. Uglietti - One of the best experts on this subject based on the ideXlab platform.
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A Prototype Conductor by React&WIND Method for the EUROfusion DEMO TF Coils
IEEE Transactions on Applied Superconductivity, 2018Co-Authors: Pierluigi Bruzzone, D. Uglietti, Rainer Wesche, Kamil Sedlak, Xabier Sarasola, Boris Stepanov, Luigi Muzzi, Antonio Della CorteAbstract:The ReactW –0.30%. After the baseline of the DEMO device was updated in 2015, the new requirements led to an updated conductor design, for 63 kA at 12.2 T. The manufacturing experience of the first prototype, named RW1, is exploited in a second short-length prototype conductor, named RW2, assembled and tested in 2017: The conductor aspect ratio is reduced, and the segregated copper wires are replaced by a solid block of mixed matrix stabilizer. Although designed for the TF coils, with dc operation, the moderate ac loss of the Flat Cable makes the RW2 a good candidate also for the central solenoid conductor. The Nb3Sn strand for RW2 is supplied by WST (PRC), and the Flat Cable is made at TRATOS (Italy). The rationale of the design, the conductor manufacture, the sample assembly, and the test results in SULTAN are reported.
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High temperature superconductors for fusion at the Swiss Plasma Center
Nuclear Fusion, 2017Co-Authors: Pierluigi Bruzzone, D. Uglietti, Rainer Wesche, Nikolay BykovskyAbstract:High temperature superconductors (HTS) may become in future an option for the superconducting magnets of commercial fusion plants. At the Swiss Plasma Center (SPC) the R&D activity toward HTS high current, high field Cables suitable for fusion magnets started in 2012 and led in 2015 to the assembly of the first 60 kA, 12 T prototype conductor. The Cable concept developed at the SPC is based on the principle of 'soldered, twisted stacks' of REBCO tapes. The required number of stacks is assembled in a cored Flat Cable, cooled by forced flow of supercritical helium. The sample environment of the test facility at SPC has been upgraded with a HTS adapter and a counter-flow heat exchanger to allow testing the HTS sample in a broader range of temperature (4.5 K–50 K) using the existing, NbTi based superconducting transformer and the closed loop refrigerator.
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Test of 60 kA coated conductor Cable prototypes for fusion magnets
Superconductor Science and Technology, 2015Co-Authors: D. Uglietti, Nikolay Bykovsky, Rainer Wesche, Kamil Sedlak, Boris Stepanov, Pierluigi BruzzoneAbstract:Coated conductors could be promising materials for the fabrication of the large magnet systems of future fusion devices. Two prototype conductors (Flat Cables in steel conduits), each about 2 m long, were manufactured using coated conductor tapes (4 mm wide) from Super Power and SuperOx, with a total tape length of 1.6 km. Each Flat Cable is assembled from 20 strands, each strand consisting of a stack of 16 tapes surrounded by two half circular copper profiles, twisted and soldered. The tapes were measured at 12 T and 4.2 K and the results of the measurements were used for the assessment of the conductor electromagnetic properties at low temperature and high field. The two conductors were assembled together in a sample that was tested in the European Dipole (EDIPO) facility. The current sharing temperatures of the two conductors were measured at background fields from 8 T up to 12 T and for currents from 30 kA up to 70 kA: the measured values are within a few percent of the values expected from the measurements on tapes (short samples). After electromagnetic cycling, T-cs at 12 T and 50 kA decreased from about 12 K to 11 K (about 10%), corresponding to less than 3% of I-c.
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design and strand tests of a fusion Cable composed of coated conductor tapes
IEEE Transactions on Applied Superconductivity, 2014Co-Authors: D. Uglietti, Rainer Wesche, P BruzzoneAbstract:The design of a Flat Cable suitable for future fusion reactors has been carried out. The Cable consists of twisted round strands, which are composed of tapes stacked between copper profiles. According to calculations, the strand twist pitch and the Cable twist pitch should be at least 1.5 or 2 m long to limit the strain and thus the reduction of the critical current. A 4-m-long strand (O6.2 mm) was fabricated on a continuous stacking and soldering line to demonstrate that the scaling up to industrial production is feasible. The strand can carry about 940 A in self-field at 77 K. The critical current evolution under bending strain was measured but it turned out to be rather fragile in “hard” bending direction. Three types of joints between strands were also manufactured and tested at 77 K.
Bae Joonbum - One of the best experts on this subject based on the ideXlab platform.
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Direct Wiring of Eutectic Gallium-Indium to a Metal Electrode for Soft Sensor Systems
AMER CHEMICAL SOC, 2019Co-Authors: Kim Suin, Jeong Dahee, Oh Jihye, Bae JoonbumAbstract:For wider applications of the liquid metal-based stretchable electronics, an electrical interface has remained as a crucial issue, due to its fragile electromechanical stability and complex fabrication steps. In this study, a direct writing-based technique is introduced to form the writing paths of conductive liquid metal (eutectic Gallium-Indium, eGaIn) and electrical connections to off-the-shelf metal electrodes in a single process. Specifically, by extending eGaIn wires written on a silicone substrate, the eGaIn wires were physically connected to the five different metal electrodes, of which stability as an electrical connection was investigated. Among the five different surface materials, the metal electrode finished by electroless nickel immersion gold (ENIG) had reproducible and low contact resistance without time-dependent variation. In our experiments, it was verified that the electrode part made by an ENIG-finished flexible Flat Cable (FFC) were mechanically (strain???100 %, pressure???600 kPa) and thermally (temperature???180 Celsius) durable. By modifying trajectories of eGaIn wires, soft sensor systems were fabricated and tested to measure finger joint angles and ground reaction forces, composed with 10 sensing units, respectively. The proposed method enables the eGaIn-based soft sensors or circuits to be connected to the typical electronic components through a FFC or weldable surfaces, using only off-the-shelf materials without additional mechanical or chemical treatments
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Direct Writing-based Wiring of Liquid Metal to a Metal Electrode for Soft Sensor Systems
'Institute of Electrical and Electronics Engineers (IEEE)', 2019Co-Authors: Kim Suin, Jeong Dahee, Oh Jihye, Bae JoonbumAbstract:As demands for stretchable electronics have increased in the field of wearable devices, liquid metal, such as eutectic Gallium-Indium (eGaIn), has gained much attention due to its metallic conductivity with liquid reconfigurability. Although various applications have been suggested using eGaIn, an electrical connection has remained as a technical challenge. Wires have been directly inserted into the microfluidic channel filled with eGaIn, resulting in electromechanically unstable connection, bulky size, and time consuming fabrication steps for the electrode part. In this study, a novel solution for the electrode is proposed, connecting eGaIn wires directly to the metal electrode based on direct writing of eGaIn. The two electrode materials were considered as candidates, including electroless nickel immersion gold (ENIG) and immersion tin (Im-Sn) plated surfaces. Among them, only the ENIG-finished surface had stable electrical connection with eGaIn, allowing sufficiently low contact resistance. The suggested electrode part was mechanically durable under strain up to 100 %. As an application, a sensing skin embedding 10 sensing units was fabricated based on direct ink writing, using a flexible Flat Cable finished by ENIG plating
Rainer Wesche - One of the best experts on this subject based on the ideXlab platform.
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A Prototype Conductor by React&WIND Method for the EUROfusion DEMO TF Coils
IEEE Transactions on Applied Superconductivity, 2018Co-Authors: Pierluigi Bruzzone, D. Uglietti, Rainer Wesche, Kamil Sedlak, Xabier Sarasola, Boris Stepanov, Luigi Muzzi, Antonio Della CorteAbstract:The ReactW –0.30%. After the baseline of the DEMO device was updated in 2015, the new requirements led to an updated conductor design, for 63 kA at 12.2 T. The manufacturing experience of the first prototype, named RW1, is exploited in a second short-length prototype conductor, named RW2, assembled and tested in 2017: The conductor aspect ratio is reduced, and the segregated copper wires are replaced by a solid block of mixed matrix stabilizer. Although designed for the TF coils, with dc operation, the moderate ac loss of the Flat Cable makes the RW2 a good candidate also for the central solenoid conductor. The Nb3Sn strand for RW2 is supplied by WST (PRC), and the Flat Cable is made at TRATOS (Italy). The rationale of the design, the conductor manufacture, the sample assembly, and the test results in SULTAN are reported.
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High temperature superconductors for fusion at the Swiss Plasma Center
Nuclear Fusion, 2017Co-Authors: Pierluigi Bruzzone, D. Uglietti, Rainer Wesche, Nikolay BykovskyAbstract:High temperature superconductors (HTS) may become in future an option for the superconducting magnets of commercial fusion plants. At the Swiss Plasma Center (SPC) the R&D activity toward HTS high current, high field Cables suitable for fusion magnets started in 2012 and led in 2015 to the assembly of the first 60 kA, 12 T prototype conductor. The Cable concept developed at the SPC is based on the principle of 'soldered, twisted stacks' of REBCO tapes. The required number of stacks is assembled in a cored Flat Cable, cooled by forced flow of supercritical helium. The sample environment of the test facility at SPC has been upgraded with a HTS adapter and a counter-flow heat exchanger to allow testing the HTS sample in a broader range of temperature (4.5 K–50 K) using the existing, NbTi based superconducting transformer and the closed loop refrigerator.
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Test of 60 kA coated conductor Cable prototypes for fusion magnets
Superconductor Science and Technology, 2015Co-Authors: D. Uglietti, Nikolay Bykovsky, Rainer Wesche, Kamil Sedlak, Boris Stepanov, Pierluigi BruzzoneAbstract:Coated conductors could be promising materials for the fabrication of the large magnet systems of future fusion devices. Two prototype conductors (Flat Cables in steel conduits), each about 2 m long, were manufactured using coated conductor tapes (4 mm wide) from Super Power and SuperOx, with a total tape length of 1.6 km. Each Flat Cable is assembled from 20 strands, each strand consisting of a stack of 16 tapes surrounded by two half circular copper profiles, twisted and soldered. The tapes were measured at 12 T and 4.2 K and the results of the measurements were used for the assessment of the conductor electromagnetic properties at low temperature and high field. The two conductors were assembled together in a sample that was tested in the European Dipole (EDIPO) facility. The current sharing temperatures of the two conductors were measured at background fields from 8 T up to 12 T and for currents from 30 kA up to 70 kA: the measured values are within a few percent of the values expected from the measurements on tapes (short samples). After electromagnetic cycling, T-cs at 12 T and 50 kA decreased from about 12 K to 11 K (about 10%), corresponding to less than 3% of I-c.
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design and strand tests of a fusion Cable composed of coated conductor tapes
IEEE Transactions on Applied Superconductivity, 2014Co-Authors: D. Uglietti, Rainer Wesche, P BruzzoneAbstract:The design of a Flat Cable suitable for future fusion reactors has been carried out. The Cable consists of twisted round strands, which are composed of tapes stacked between copper profiles. According to calculations, the strand twist pitch and the Cable twist pitch should be at least 1.5 or 2 m long to limit the strain and thus the reduction of the critical current. A 4-m-long strand (O6.2 mm) was fabricated on a continuous stacking and soldering line to demonstrate that the scaling up to industrial production is feasible. The strand can carry about 940 A in self-field at 77 K. The critical current evolution under bending strain was measured but it turned out to be rather fragile in “hard” bending direction. Three types of joints between strands were also manufactured and tested at 77 K.
Nikolay Bykovsky - One of the best experts on this subject based on the ideXlab platform.
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High temperature superconductors for fusion at the Swiss Plasma Center
Nuclear Fusion, 2017Co-Authors: Pierluigi Bruzzone, D. Uglietti, Rainer Wesche, Nikolay BykovskyAbstract:High temperature superconductors (HTS) may become in future an option for the superconducting magnets of commercial fusion plants. At the Swiss Plasma Center (SPC) the R&D activity toward HTS high current, high field Cables suitable for fusion magnets started in 2012 and led in 2015 to the assembly of the first 60 kA, 12 T prototype conductor. The Cable concept developed at the SPC is based on the principle of 'soldered, twisted stacks' of REBCO tapes. The required number of stacks is assembled in a cored Flat Cable, cooled by forced flow of supercritical helium. The sample environment of the test facility at SPC has been upgraded with a HTS adapter and a counter-flow heat exchanger to allow testing the HTS sample in a broader range of temperature (4.5 K–50 K) using the existing, NbTi based superconducting transformer and the closed loop refrigerator.
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Test of 60 kA coated conductor Cable prototypes for fusion magnets
Superconductor Science and Technology, 2015Co-Authors: D. Uglietti, Nikolay Bykovsky, Rainer Wesche, Kamil Sedlak, Boris Stepanov, Pierluigi BruzzoneAbstract:Coated conductors could be promising materials for the fabrication of the large magnet systems of future fusion devices. Two prototype conductors (Flat Cables in steel conduits), each about 2 m long, were manufactured using coated conductor tapes (4 mm wide) from Super Power and SuperOx, with a total tape length of 1.6 km. Each Flat Cable is assembled from 20 strands, each strand consisting of a stack of 16 tapes surrounded by two half circular copper profiles, twisted and soldered. The tapes were measured at 12 T and 4.2 K and the results of the measurements were used for the assessment of the conductor electromagnetic properties at low temperature and high field. The two conductors were assembled together in a sample that was tested in the European Dipole (EDIPO) facility. The current sharing temperatures of the two conductors were measured at background fields from 8 T up to 12 T and for currents from 30 kA up to 70 kA: the measured values are within a few percent of the values expected from the measurements on tapes (short samples). After electromagnetic cycling, T-cs at 12 T and 50 kA decreased from about 12 K to 11 K (about 10%), corresponding to less than 3% of I-c.