Venkat Selvamanickam - Academia.edu (original) (raw)

Uploads

Papers by Venkat Selvamanickam

Research paper thumbnail of Influence of external magnetic field and its orientation on transport AC losses in Bi2223 and Tl1223 silver sheathed tapes

IEEE Transactions on Applied Superconductivity, 1997

In the paper we report measurements of energy losses caused by an AC transport current in silver ... more In the paper we report measurements of energy losses caused by an AC transport current in silver sheathed multifilamentary Bi-2223 and mono core Tl-1223 tapes, as a function of the magnitude and orientation of the applied external magnetic field. The external magnetic field was rotated in the range of 0 to ±90 degrees with respect to the plane of the

Research paper thumbnail of Processing of thallium-based superconducting tapes for high current density

Physica C-superconductivity and Its Applications, 1996

Optimum thermomechanical processing conditions have been developed to achieve a high current dens... more Optimum thermomechanical processing conditions have been developed to achieve a high current density in powder-in-tube (PIT) thallium-based (Tl,Pb)-1223 and (Tl,Bi)-1223 tapes. Critical currents in excess of 25 A corresponding to a current density of 20 000 A/cm2 have been achieved in these tapes at 77 K. Heat treatment and intermediate deformation sequences, heating rates, and starting precursor phase assemblages have

Research paper thumbnail of Development and test of world's first industrial high temperature superconducting (HTS) power cable

Southwire Company has installed the world's first industrial high-temperature superconducting cab... more Southwire Company has installed the world's first industrial high-temperature superconducting cable system to power three of its main manufacturing plants. The cable consists of three single-phase, 30 m long cables designed to carry 1250 A at 12.4 kV. The cable is cooled by a liquid nitrogen (LN) system that can supply LN at sub-cooled temperatures down to 72 K and at pressures up to 15 atmospheres. The design of the 30 m cables is based upon two 5 m cable prototypes, which were tested at a specially developed facility at ORNL. In addition to critical current and AC loss measurements, simulated fault-current tests were performed at ORNL on the 5 m cables. Cable terminations were designed to allow smooth transition from the cryogenic temperature and pressure environment of the HTS cable to ambient temperature and pressure for copper cables. A dielectric tape material, CryoflexTM was also developed for use at cryogenic temperatures

Research paper thumbnail of Recent Developments in 2G HTS Coil Technology

IEEE Transactions on Applied Superconductivity, 2009

Research paper thumbnail of SuperPower's YBCO Coated High-Temperature Superconducting (HTS) Wire and Magnet Applications

Proceedings of The IEEE, 2009

Recent developments in second-generation (2G) HTS wire and coil technology are presented highligh... more Recent developments in second-generation (2G) HTS wire and coil technology are presented highlighting the ability of 2G HTS wire to function under demanding operating conditions associated with many applications including linear motors for transportation. The challenges of use in various coil constructions and applications are discussed. The 2G wire architecture of a structural substrate, buffer stack, HTS layer, and stabilization enables the 2G wire to tolerate high stress levels while providing the high current density required for lightweight, compact magnets. The high winding current density that is available with SuperPower's thin (0.1 mm) 2G HTS wire has been utilized in several coil demonstrations, including one generating central fields in excess of 26.8 T. The ability of the wire to be tailored (stabilization, insulation, ac losses) to fit various operating parameters will also be discussed.

Research paper thumbnail of Texture development and superconducting properties of YBCO thick films deposited on buffered metal substrates at various deposition rates

IEEE Transactions on Applied Superconductivity, 2003

Research paper thumbnail of Fast growth process of long-length YBCO coated conductor with high critical current density

IEEE Transactions on Applied Superconductivity, 2005

Research paper thumbnail of Texture development and superconducting properties of YBCO thick films deposited on buffered metal substrates at various deposition rates

IEEE Transactions on Applied Superconductivity, 2003

Research paper thumbnail of Fast growth process of long-length YBCO coated conductor with high critical current density

IEEE Transactions on Applied Superconductivity, 2005

Research paper thumbnail of Scale up of high-performance Y-Ba-Cu-O coated conductors

IEEE Transactions on Applied Superconductivity, 2003

YBa2Cu3Ox (YBCO) coated conductors have been produced in meter lengths in pilot scale facilities ... more YBa2Cu3Ox (YBCO) coated conductors have been produced in meter lengths in pilot scale facilities established at IGC-SuperPower. Highly-smooth nickel alloy substrates have been polished in reel-to-reel polishing facility, with a uniform roughness of 2 nm. A pilot-scale ion beam assisted deposition (IBAD) facility has been used to produce 1 to 5 m lengths of buffered tapes with a uniform in-plane

Research paper thumbnail of Microstructural and superconducting properties of high current metal-organic chemical vapor deposition YBa2Cu3O7-delta coated conductor wires

Superconductor Science & Technology, 2009

Research paper thumbnail of High-current Y–Ba–Cu–O superconducting films by metal organic chemical vapor deposition on flexible metal substrates

Physica C-superconductivity and Its Applications, 2000

Research paper thumbnail of Second Generation High-Temperature Superconducting Wires for Fault Current Limiter Applications

IEEE Transactions on Applied Superconductivity, 2007

Since a superconductor has no resistance below a certain temperature and can therefore save a lar... more Since a superconductor has no resistance below a certain temperature and can therefore save a large amount of energy dissipated, it is a 'green' material by saving energy loss and hence reducing carbon emissions. Recently the massive manufacture of high-temperature ...

Research paper thumbnail of Fabrication of 100 A class, 1 m long coated conductor tapes by metal organic chemical vapor deposition and pulsed laser deposition

Physica C-superconductivity and Its Applications, 2003

Research paper thumbnail of Progress in High Throughput Processing of Long-Length, High Quality, and Low Cost IBAD MgO Buffer Tapes at SuperPower

IEEE Transactions on Applied Superconductivity, 2009

Research paper thumbnail of Advances in fabrication of Ag-clad Bi2223 superconductors

IEEE Transactions on Applied Superconductivity, 1999

Powder-in-tube (PIT) processing was used to fabricate multifilamentary Ag-clad Bi/sub 2/Sr/sub 2/... more Powder-in-tube (PIT) processing was used to fabricate multifilamentary Ag-clad Bi/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub y/ (Bi-2223) superconductors for various electric power applications. The transport current properties of long lengths of multifilament tapes were enhanced by increasing the packing density of the precursor powder, improving the mechanical deformation, and adjusting the cooling rate. The dependence of the critical current density on magnetic field and temperature for the optimally processed tapes was measured. J/sub c/ was >10/sup 4/ A/cm/sup 2/ at 20 K in magnetic fields up to 3 T and parallel to the c-axis, which is of interest for use in refrigerator-cooled magnets.

Research paper thumbnail of High-current Y-Ba-Cu-O coated conductor using metal organic chemical-vapor deposition and ion-beam-assisted deposition

IEEE Transactions on Applied Superconductivity, 2001

Research paper thumbnail of Scale up of applications-ready practical Y-Ba-Cu-O coated conductors

IEEE Transactions on Applied Superconductivity, 2005

YBa2Cu3Ox (YBCO) coated conductors have been produced in 100 m lengths in pilot scale facilities ... more YBa2Cu3Ox (YBCO) coated conductors have been produced in 100 m lengths in pilot scale facilities established at SuperPower. In addition to scaling up coated conductors to long lengths with high critical current, we have modified the basic conductor for enhanced in-field performance and low ac losses. In addition, our coated conductors have been produced in practical configurations in 4 mm widths and with a surround copper stabilizer. The conductors were slit first to a 4 mm width and then subjected to electroplating to apply the copper stabilizer. Mechanical and electrical properties of the complete conductor have been elaborately tested. 61 m of 4 mm wide, surround copper stabilized conductor was provided to Sumitomo Electric Industries who fabricated a 1 m cable using the conductor. The cable exhibited the lowest ac losses reported with HTS conductors. SuperPower also fabricated a pancake coil with 7.4 m of coated conductor, which generated a maximum magnetic field of 0.28 T at 77 K.

Research paper thumbnail of Progress in second-generation HTS wire development and manufacturing

Physica C-superconductivity and Its Applications, 2008

2007 has marked yet another year of continued rapid progress in developing and manufacturing high... more 2007 has marked yet another year of continued rapid progress in developing and manufacturing high-performance, long-length second-generation (2G) HTS wires at high speeds. Using ion beam assisted deposition (IBAD) MgO and associated buffer sputtering processes, SuperPower has now exceeded piece lengths of 1000m of fully buffered tape reproducibly with excellent in-plane texture of 6–7 degrees and uniformity of about 2%.

Research paper thumbnail of Stability and quench protection of coated YBCO "Composite" tape

IEEE Transactions on Applied Superconductivity, 2005

Research paper thumbnail of Influence of external magnetic field and its orientation on transport AC losses in Bi2223 and Tl1223 silver sheathed tapes

IEEE Transactions on Applied Superconductivity, 1997

In the paper we report measurements of energy losses caused by an AC transport current in silver ... more In the paper we report measurements of energy losses caused by an AC transport current in silver sheathed multifilamentary Bi-2223 and mono core Tl-1223 tapes, as a function of the magnitude and orientation of the applied external magnetic field. The external magnetic field was rotated in the range of 0 to ±90 degrees with respect to the plane of the

Research paper thumbnail of Processing of thallium-based superconducting tapes for high current density

Physica C-superconductivity and Its Applications, 1996

Optimum thermomechanical processing conditions have been developed to achieve a high current dens... more Optimum thermomechanical processing conditions have been developed to achieve a high current density in powder-in-tube (PIT) thallium-based (Tl,Pb)-1223 and (Tl,Bi)-1223 tapes. Critical currents in excess of 25 A corresponding to a current density of 20 000 A/cm2 have been achieved in these tapes at 77 K. Heat treatment and intermediate deformation sequences, heating rates, and starting precursor phase assemblages have

Research paper thumbnail of Development and test of world's first industrial high temperature superconducting (HTS) power cable

Southwire Company has installed the world's first industrial high-temperature superconducting cab... more Southwire Company has installed the world's first industrial high-temperature superconducting cable system to power three of its main manufacturing plants. The cable consists of three single-phase, 30 m long cables designed to carry 1250 A at 12.4 kV. The cable is cooled by a liquid nitrogen (LN) system that can supply LN at sub-cooled temperatures down to 72 K and at pressures up to 15 atmospheres. The design of the 30 m cables is based upon two 5 m cable prototypes, which were tested at a specially developed facility at ORNL. In addition to critical current and AC loss measurements, simulated fault-current tests were performed at ORNL on the 5 m cables. Cable terminations were designed to allow smooth transition from the cryogenic temperature and pressure environment of the HTS cable to ambient temperature and pressure for copper cables. A dielectric tape material, CryoflexTM was also developed for use at cryogenic temperatures

Research paper thumbnail of Recent Developments in 2G HTS Coil Technology

IEEE Transactions on Applied Superconductivity, 2009

Research paper thumbnail of SuperPower's YBCO Coated High-Temperature Superconducting (HTS) Wire and Magnet Applications

Proceedings of The IEEE, 2009

Recent developments in second-generation (2G) HTS wire and coil technology are presented highligh... more Recent developments in second-generation (2G) HTS wire and coil technology are presented highlighting the ability of 2G HTS wire to function under demanding operating conditions associated with many applications including linear motors for transportation. The challenges of use in various coil constructions and applications are discussed. The 2G wire architecture of a structural substrate, buffer stack, HTS layer, and stabilization enables the 2G wire to tolerate high stress levels while providing the high current density required for lightweight, compact magnets. The high winding current density that is available with SuperPower's thin (0.1 mm) 2G HTS wire has been utilized in several coil demonstrations, including one generating central fields in excess of 26.8 T. The ability of the wire to be tailored (stabilization, insulation, ac losses) to fit various operating parameters will also be discussed.

Research paper thumbnail of Texture development and superconducting properties of YBCO thick films deposited on buffered metal substrates at various deposition rates

IEEE Transactions on Applied Superconductivity, 2003

Research paper thumbnail of Fast growth process of long-length YBCO coated conductor with high critical current density

IEEE Transactions on Applied Superconductivity, 2005

Research paper thumbnail of Texture development and superconducting properties of YBCO thick films deposited on buffered metal substrates at various deposition rates

IEEE Transactions on Applied Superconductivity, 2003

Research paper thumbnail of Fast growth process of long-length YBCO coated conductor with high critical current density

IEEE Transactions on Applied Superconductivity, 2005

Research paper thumbnail of Scale up of high-performance Y-Ba-Cu-O coated conductors

IEEE Transactions on Applied Superconductivity, 2003

YBa2Cu3Ox (YBCO) coated conductors have been produced in meter lengths in pilot scale facilities ... more YBa2Cu3Ox (YBCO) coated conductors have been produced in meter lengths in pilot scale facilities established at IGC-SuperPower. Highly-smooth nickel alloy substrates have been polished in reel-to-reel polishing facility, with a uniform roughness of 2 nm. A pilot-scale ion beam assisted deposition (IBAD) facility has been used to produce 1 to 5 m lengths of buffered tapes with a uniform in-plane

Research paper thumbnail of Microstructural and superconducting properties of high current metal-organic chemical vapor deposition YBa2Cu3O7-delta coated conductor wires

Superconductor Science & Technology, 2009

Research paper thumbnail of High-current Y–Ba–Cu–O superconducting films by metal organic chemical vapor deposition on flexible metal substrates

Physica C-superconductivity and Its Applications, 2000

Research paper thumbnail of Second Generation High-Temperature Superconducting Wires for Fault Current Limiter Applications

IEEE Transactions on Applied Superconductivity, 2007

Since a superconductor has no resistance below a certain temperature and can therefore save a lar... more Since a superconductor has no resistance below a certain temperature and can therefore save a large amount of energy dissipated, it is a 'green' material by saving energy loss and hence reducing carbon emissions. Recently the massive manufacture of high-temperature ...

Research paper thumbnail of Fabrication of 100 A class, 1 m long coated conductor tapes by metal organic chemical vapor deposition and pulsed laser deposition

Physica C-superconductivity and Its Applications, 2003

Research paper thumbnail of Progress in High Throughput Processing of Long-Length, High Quality, and Low Cost IBAD MgO Buffer Tapes at SuperPower

IEEE Transactions on Applied Superconductivity, 2009

Research paper thumbnail of Advances in fabrication of Ag-clad Bi2223 superconductors

IEEE Transactions on Applied Superconductivity, 1999

Powder-in-tube (PIT) processing was used to fabricate multifilamentary Ag-clad Bi/sub 2/Sr/sub 2/... more Powder-in-tube (PIT) processing was used to fabricate multifilamentary Ag-clad Bi/sub 2/Sr/sub 2/Ca/sub 2/Cu/sub 3/O/sub y/ (Bi-2223) superconductors for various electric power applications. The transport current properties of long lengths of multifilament tapes were enhanced by increasing the packing density of the precursor powder, improving the mechanical deformation, and adjusting the cooling rate. The dependence of the critical current density on magnetic field and temperature for the optimally processed tapes was measured. J/sub c/ was >10/sup 4/ A/cm/sup 2/ at 20 K in magnetic fields up to 3 T and parallel to the c-axis, which is of interest for use in refrigerator-cooled magnets.

Research paper thumbnail of High-current Y-Ba-Cu-O coated conductor using metal organic chemical-vapor deposition and ion-beam-assisted deposition

IEEE Transactions on Applied Superconductivity, 2001

Research paper thumbnail of Scale up of applications-ready practical Y-Ba-Cu-O coated conductors

IEEE Transactions on Applied Superconductivity, 2005

YBa2Cu3Ox (YBCO) coated conductors have been produced in 100 m lengths in pilot scale facilities ... more YBa2Cu3Ox (YBCO) coated conductors have been produced in 100 m lengths in pilot scale facilities established at SuperPower. In addition to scaling up coated conductors to long lengths with high critical current, we have modified the basic conductor for enhanced in-field performance and low ac losses. In addition, our coated conductors have been produced in practical configurations in 4 mm widths and with a surround copper stabilizer. The conductors were slit first to a 4 mm width and then subjected to electroplating to apply the copper stabilizer. Mechanical and electrical properties of the complete conductor have been elaborately tested. 61 m of 4 mm wide, surround copper stabilized conductor was provided to Sumitomo Electric Industries who fabricated a 1 m cable using the conductor. The cable exhibited the lowest ac losses reported with HTS conductors. SuperPower also fabricated a pancake coil with 7.4 m of coated conductor, which generated a maximum magnetic field of 0.28 T at 77 K.

Research paper thumbnail of Progress in second-generation HTS wire development and manufacturing

Physica C-superconductivity and Its Applications, 2008

2007 has marked yet another year of continued rapid progress in developing and manufacturing high... more 2007 has marked yet another year of continued rapid progress in developing and manufacturing high-performance, long-length second-generation (2G) HTS wires at high speeds. Using ion beam assisted deposition (IBAD) MgO and associated buffer sputtering processes, SuperPower has now exceeded piece lengths of 1000m of fully buffered tape reproducibly with excellent in-plane texture of 6–7 degrees and uniformity of about 2%.

Research paper thumbnail of Stability and quench protection of coated YBCO "Composite" tape

IEEE Transactions on Applied Superconductivity, 2005