Tanna Vipul | Karlsruhe University (original) (raw)

Papers by Tanna Vipul

Research paper thumbnail of Test Results of a Prototype HTS Current Lead With MgB2 and NbTi Superconducting Joints

IEEE Transactions on Applied Superconductivity

Research paper thumbnail of Superconducting current feeder system with associated test results for SST1 Tokamak

IEEE Transactions on Applied Superconductivity, 2004

The current feeder system (CFS) consists of 20 numbers 10 kA current leads assembled inside a spe... more The current feeder system (CFS) consists of 20 numbers 10 kA current leads assembled inside a specially designed cryostat, superconducting bus bars assembled in a vacuum duct with bends and the joint box interface in cryogenic environment at 4.5 K. Support structure between room temperature and 4.5 K surfaces with an intercept at 80 K has been designed specially to minimize the conduction heat load as well as to take care of the electromagnetic forces. The hydraulics design of the CFS has been optimized in order to be able to interface with the liquid helium refrigerator/liquefier. A sophisticated instrumentation and control system has been designed and developed as well as tested. The paper describe the design concepts, mechanical and hydraulic analysis, instrumentation & control system as well as some test results of the current feeder system.

Research paper thumbnail of Conceptual design of a High Temperature Superconductor current feeder system for ITER

Journal of Physics: Conference Series, 2006

... R. Wesche3, and GR Zahn1 1Forschungszentrum Karlsruhe, Karlsruhe, Germany 2 European Fusion D... more ... R. Wesche3, and GR Zahn1 1Forschungszentrum Karlsruhe, Karlsruhe, Germany 2 European Fusion Development Agreement, Close Support Unit, Garching, Germany 3Centre de Recherches en Physique des Plasmas, Villigen, Switzerland E-mail: vipul.tanna@itp.fzk.de ...

Research paper thumbnail of Trapping of dust and dust acoustic waves in laboratory plasmas

Physics of Plasmas, 1996

Trapping of negatively charged dust particles is observed in a hot cathode plasma discharge when ... more Trapping of negatively charged dust particles is observed in a hot cathode plasma discharge when a layer of dust is exposed to the plasma. The particles are visible in the scattered He-Ne laser light. The trajectories of individual particles have been photographed. The dust particles are excluded from the sheath region of any object in the plasma. The intensity of scattered light as well as the potential on a floating Langmuir probe show coherent fluctuations in the frequency range 1-15 Hz. After several hours of exposure to the plasma, the dust layer develops striations similar to those on sand dunes. Trapping of dust particles by the plasma and the possible identification of the observed low-frequency fluctuations with dust acoustic waves are discussed.

Research paper thumbnail of Integrated cryogenic fluid flow distribution and cooling scheme with helium liquefier/refrigerator for SST1 magnet system

IEEE Transactions on Applied Superconductivity, 2004

The thermo-hydraulic analysis shows that a total of 300 g/s supercritical helium (SHe) flow is re... more The thermo-hydraulic analysis shows that a total of 300 g/s supercritical helium (SHe) flow is required for the superconducting magnet system (SCMS) of steady state superconducting tokamak, SST-1, including the bus lines to keep sufficient temperature margin of the conductor. The heat received from the SCMS is removed from the circulating SHe through a heat exchanger placed in the Main Control Dewar (MCD). SHe flow distribution among different paths of SCMS has been optimized on the basis of steady state as well as pulsed heat load as per required stability margins of the coils. An integrated flow distribution and control (IFDC) system has been designed, fabricated, installed and tested to control the flow rate in SCMS. The IFDC system has been designed also to take care for safe handling of cryogen following quench in SCMS. The paper describes the cooling scheme of SCMS with the refrigerator/liquefier (R/L) and the role of IFDC system toward all operational modes of SCMS with the R/L.

Research paper thumbnail of 70 kA High Temperature Superconductor Current Lead Operation at 80 K

IEEE Transactions on Applied Superconductivity, 2006

For the superconducting magnet system of the International Thermonuclear Experimental Reactor, IT... more For the superconducting magnet system of the International Thermonuclear Experimental Reactor, ITER, 60 current leads for a total current of more than 2500 kA are needed. To reduce the resultant large refrigerator load at 4.5 K, High Temperature Superconductor current leads (HTS-CL) could be used. Therefore, EFDA CSU Garching had launched a development program for a 70 kA HTS-CL demonstrator. The Forschungszentrum Karlsruhe and CRPP developed and built this CL optimized for 50 K Helium operation. In 2004, the CL was successfully tested in the TOSKA facility at the Forschungszentrum Karlsruhe. The very encouraging results lead to testing this CL with 80 K Helium because ITER provides a large 80 K Helium cooling capacity for the thermal shields. At the end of last year, the test could be successfully performed demonstrating that high current capacity current leads can be stably operated at about 80-85 K. Recently, the CL was retested using liquid nitrogen which would be an interesting alternative option.

Research paper thumbnail of Experimental results of a 70 kA high temperature superconductor current lead demonstrator for the ITER magnet system

IEEE Transactions on Applied Superconductivity, 2005

In the frame of the European Fusion Technology Programme, the Forschungszentrum Karlsruhe and the... more In the frame of the European Fusion Technology Programme, the Forschungszentrum Karlsruhe and the CRPP Villigen have designed and built a 70 kA current lead for the ITER TF Coils using High Temperature Superconductors (HTS). At the beginning of 2004 the HTS current lead was installed and tested in the TOSKA facility of the Forschungszentrum Karlsruhe. The scope of the

Research paper thumbnail of SST1 Status and Plans

IEEE Transactions on Plasma Science, 2012

Page 1. This article has been accepted for inclusion in a future issue of this journal. Content i... more Page 1. This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination. IEEE TRANSACTIONS ON PLASMA SCIENCE 1 SST-1 Status and Plans Subrata ...

Research paper thumbnail of Test Results of a Prototype HTS Current Lead With MgB2 and NbTi Superconducting Joints

IEEE Transactions on Applied Superconductivity

Research paper thumbnail of Superconducting current feeder system with associated test results for SST1 Tokamak

IEEE Transactions on Applied Superconductivity, 2004

The current feeder system (CFS) consists of 20 numbers 10 kA current leads assembled inside a spe... more The current feeder system (CFS) consists of 20 numbers 10 kA current leads assembled inside a specially designed cryostat, superconducting bus bars assembled in a vacuum duct with bends and the joint box interface in cryogenic environment at 4.5 K. Support structure between room temperature and 4.5 K surfaces with an intercept at 80 K has been designed specially to minimize the conduction heat load as well as to take care of the electromagnetic forces. The hydraulics design of the CFS has been optimized in order to be able to interface with the liquid helium refrigerator/liquefier. A sophisticated instrumentation and control system has been designed and developed as well as tested. The paper describe the design concepts, mechanical and hydraulic analysis, instrumentation & control system as well as some test results of the current feeder system.

Research paper thumbnail of Conceptual design of a High Temperature Superconductor current feeder system for ITER

Journal of Physics: Conference Series, 2006

... R. Wesche3, and GR Zahn1 1Forschungszentrum Karlsruhe, Karlsruhe, Germany 2 European Fusion D... more ... R. Wesche3, and GR Zahn1 1Forschungszentrum Karlsruhe, Karlsruhe, Germany 2 European Fusion Development Agreement, Close Support Unit, Garching, Germany 3Centre de Recherches en Physique des Plasmas, Villigen, Switzerland E-mail: vipul.tanna@itp.fzk.de ...

Research paper thumbnail of Trapping of dust and dust acoustic waves in laboratory plasmas

Physics of Plasmas, 1996

Trapping of negatively charged dust particles is observed in a hot cathode plasma discharge when ... more Trapping of negatively charged dust particles is observed in a hot cathode plasma discharge when a layer of dust is exposed to the plasma. The particles are visible in the scattered He-Ne laser light. The trajectories of individual particles have been photographed. The dust particles are excluded from the sheath region of any object in the plasma. The intensity of scattered light as well as the potential on a floating Langmuir probe show coherent fluctuations in the frequency range 1-15 Hz. After several hours of exposure to the plasma, the dust layer develops striations similar to those on sand dunes. Trapping of dust particles by the plasma and the possible identification of the observed low-frequency fluctuations with dust acoustic waves are discussed.

Research paper thumbnail of Integrated cryogenic fluid flow distribution and cooling scheme with helium liquefier/refrigerator for SST1 magnet system

IEEE Transactions on Applied Superconductivity, 2004

The thermo-hydraulic analysis shows that a total of 300 g/s supercritical helium (SHe) flow is re... more The thermo-hydraulic analysis shows that a total of 300 g/s supercritical helium (SHe) flow is required for the superconducting magnet system (SCMS) of steady state superconducting tokamak, SST-1, including the bus lines to keep sufficient temperature margin of the conductor. The heat received from the SCMS is removed from the circulating SHe through a heat exchanger placed in the Main Control Dewar (MCD). SHe flow distribution among different paths of SCMS has been optimized on the basis of steady state as well as pulsed heat load as per required stability margins of the coils. An integrated flow distribution and control (IFDC) system has been designed, fabricated, installed and tested to control the flow rate in SCMS. The IFDC system has been designed also to take care for safe handling of cryogen following quench in SCMS. The paper describes the cooling scheme of SCMS with the refrigerator/liquefier (R/L) and the role of IFDC system toward all operational modes of SCMS with the R/L.

Research paper thumbnail of 70 kA High Temperature Superconductor Current Lead Operation at 80 K

IEEE Transactions on Applied Superconductivity, 2006

For the superconducting magnet system of the International Thermonuclear Experimental Reactor, IT... more For the superconducting magnet system of the International Thermonuclear Experimental Reactor, ITER, 60 current leads for a total current of more than 2500 kA are needed. To reduce the resultant large refrigerator load at 4.5 K, High Temperature Superconductor current leads (HTS-CL) could be used. Therefore, EFDA CSU Garching had launched a development program for a 70 kA HTS-CL demonstrator. The Forschungszentrum Karlsruhe and CRPP developed and built this CL optimized for 50 K Helium operation. In 2004, the CL was successfully tested in the TOSKA facility at the Forschungszentrum Karlsruhe. The very encouraging results lead to testing this CL with 80 K Helium because ITER provides a large 80 K Helium cooling capacity for the thermal shields. At the end of last year, the test could be successfully performed demonstrating that high current capacity current leads can be stably operated at about 80-85 K. Recently, the CL was retested using liquid nitrogen which would be an interesting alternative option.

Research paper thumbnail of Experimental results of a 70 kA high temperature superconductor current lead demonstrator for the ITER magnet system

IEEE Transactions on Applied Superconductivity, 2005

In the frame of the European Fusion Technology Programme, the Forschungszentrum Karlsruhe and the... more In the frame of the European Fusion Technology Programme, the Forschungszentrum Karlsruhe and the CRPP Villigen have designed and built a 70 kA current lead for the ITER TF Coils using High Temperature Superconductors (HTS). At the beginning of 2004 the HTS current lead was installed and tested in the TOSKA facility of the Forschungszentrum Karlsruhe. The scope of the

Research paper thumbnail of SST1 Status and Plans

IEEE Transactions on Plasma Science, 2012

Page 1. This article has been accepted for inclusion in a future issue of this journal. Content i... more Page 1. This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination. IEEE TRANSACTIONS ON PLASMA SCIENCE 1 SST-1 Status and Plans Subrata ...