| 1. |
KISS,Takanobu; TAKARABE,Yusuke; SHIGEOKA,Shun; WU,Zeyu; IMAMURA,Kazutaka; HIGASHIKAWA,Kohei; YOKOE,Daisaku; ITOH,Taishi; KATO,Takeharu; MIURA,Hideaki; HATTORI,Taisuke; OYA,Masayoshi; TONOOKA,Shun, Hybrid Microscopy to Clarify Failure Mechanisms of REBCO Tapes in Meter-Class Pancake-Coils, 27th International Conference on Magnet Technology (MT27), 2021.11. |
| 2. |
Takanobu Kiss, Peihong Zhang, Yuhsuke Oda, Keita Kawasaki, Zeyu Wu, Kenji Suzuki, Kohei Higashikawa, Shigeru Sato, Novel continuous bending test method applicable to a small diameter less than 10 mm and a development of flexible REBCO joints, 10th MEM Mechanical and Electromagnetic Properties of Composite Superconductors, 2022.07, In this study, bending properties of REBCO tapes and their joints have been investigated by a novel continuous bending property test method of small diameter, and we have succeeded in realizing excellent flexible joining to retain the initial Ic of 95 % or more at the minimum bending diameter of 6 mm. REBCO wire is much superior to BSCCO wire on bending property because of the thin film deposited on the thin substrate. However, the bending test of small diameter has not been sufficiently investigated due to the restriction of the size of the jig, etc. In this study, we proposed a novel bending test method in which REBCO tapes were bent in a loop. Based on image analysis of the loops, we found that the shape of the loop can be described by the clothoid curve in which the curvature linearly changes along the trajectory. This allows us to control the loop diameter by the sample length. Experimental results showed good agreement with that of theoretical analysis. Applying this bending test method, we examined bending characteristics of REBCO tape and bonded samples. While the critical bending diameter was 12 mm in the REBCO tape strand, the bonded samples showed excellent flexibility which surpassed the characteristics of the strand as the position of superconducting layer approaches closer to the neutral line in the bonded sample. We have achieved 6 mm in diameter as the minimum value in the joint.
Acknowledgements: This work was supported by JSPS KAKENHI Grant Number JP19H05617.. |
| 3. |
Takanobu Kiss, Natthawirot Somjaijaroen, Mingyang Gao, Kazutaka Imamura, Zeyu Wu, Kohei Higashikawa, Advancement of magnetic microscopy by introducing deep-learning based image analyses for high performance characterization of REBCO coated conductors, 2022 The Applied Superconductivity Conference (ASC2022), 2022.10. |
| 4. |
Takanobu Kiss, Natthawirot Somjaijaroen, Kazutaka Imamura, Takuya Terazaki, Zeyu Wu, Kohei Higashikawa, [Invited] Automatic Detection of Local Inhomogeneity in REBCO Coated Conductor by High-Speed Reel-to-Reel Scanning Hall Probe Magnetic Microscopy Coupled with Machine Learning Based Image Analysis（招待講演）, 2022 International Forum on Applied Superconductivity and Magnetism, 2022.12. |
| 5. |
Zeyu Wu, Kohei Higashikawa, Natthawirot Somjaijaroen, Kazutaka Imamura, Takanobu Kiss, High-resolution Detection of Localized Jc inhomogeneity in long-length REBCO Coated Conductor by Combining Magnetic Microscopy and Deep Learning-based Object Detection, MT-28 International Conference on Magnet Technology, 2023.09. |
| 6. |
Zeyu Wu, K. Higashikawa, A. Queraltó, C. Pop, K. Gupta, X. Obradors, T. Puig, T. Kiss, Spatially Resolved Analysis of Local Jc in a Combinatorial Inkjet Printing for Transient LiquidAssisted Growth Chemical Solution Deposition, The 11th Asian Conference on Applied Superconductivity and Cryogenics / 3rd Asian International Cryogenic Materials Conference(ACASC-Asian ICMC 2023), 2023.10. |
| 7. |
Zeyu Wu, Kohei Higashikawa, Natthawirot Somjaijaroen, Kazutaka Imamura,Takanobu Kiss, Analysis of Current Blocking Obstacles in Long-length Coated Conductors by the Combination of High-Throughput Reel-to-Reel Magnetic Microscopy and Machine Learning, The 36th International Symposium on Superconductivity (ISS2023) , 2023.11. |
| 8. |
T.Kiss, On the possibility of an alternative explanation of vortex glass-liquid transition (Invited), International Seminar on Superconducting State and Transport Phenomena in High Magnetic Fields, 1995.05.. |
| 9. |
T. Kiss, K. Yamafuji, Glass-Liquid Transition and Flux Pinning in High T$_{c}$ Superconductors (invited), Int. Workshop on New Phys. in the Vortex State of the High Temp. Superconductors, 1996.04.. |
| 10. |
T. Kiss, T. Nakamura, M. Takeo, F. Irie, K. Yamafuji, Transport Characteristics in High T$_{c}$ Superconductors with Pin Fluctuation under The Influence of Thermal Agitation (invited), 8th Int. Workshop on Critical Current in Superconductors, 1996.05.. |
| 11. |
T. Kiss, T. Matsushita, F. Irie, Relationship among flux depinning, irreversibility and phase transition in a disordered HTS material (invited), The 9th International Workshop on Critical Currents (IWCC9-99), 1999.07.. |
| 12. |
T. Kiss, Transport $E$-$J$ Characteristics in HTS (invited), The International Workshop on Critical Currents and Applications of HTS (IWCCA-HTS, Satellite Conf. to ISS 200), 2000.10.. |
| 13. |
T. Kiss, S. Nishimura, M. Inoue, H. Okamoto, Y. Sumiyoshi, T. Matsushita, Y. Iijima, K. Kakimoto, T. Saitoh, S. Awaji, K. Watanabe, Y. Shiohara, Critical current properties of high Tc superconducting tapes (Invited), US/Japan Workshop on Application of high temperature superconducting coil for fusion plasma experimental devices, 2002.02.. |
| 14. |
T. Kiss, M. Inoue, T. Kuga, M. Ishimaru, S. Egashira, T. Ohta, K. Imamura, M. Yasunaga, M. Takeo, T. Matsushita, Y. Iijima, K. Kakimoto, T. Saitoh, S. Awaji, K. Watanabe, Y. Shiohara, Critical currents in YBCO superconducting tapes (Invited), MRS Superconductivity Workshop: International Workshop on Processing and Applications of Superconductors, 2002.08.. |
| 15. |
T. Kiss, M. Inoue, T. Kuga, M. Ishimaru, S. Egashira, T. Ohta, K. Imamura, M. Yasunaga, M. Takeo, T. Matsushita, Y. Iijima, K. Kakimoto, T. Saitoh, S. Awaji, K. Watanabe, Y. Shiohara, Critical current properties in HTS tapes (Invited), International Symposium on Superconductivity(ISS) 2002, 2002.11.. |
| 16. |
T. Kiss, M. Inoue, T. Kuga, M. Ishimaru, S. Egashira, T. Ohta, K. Imamura, M. Yasunaga, M. Takeo, T. Matsushita, Y. Iijima, K. Kakimoto, T. Saitoh, S. Awaji, K. Watanabe, Y. Shiohara, Current-voltage characteristics in YBCO coated IBAD tapes (Invited), MRS Fall meeting, 2002.12.. |
| 17. |
T. Kiss, Critical Current Densities: Percolation and Scaling, American Physical Society March Meeting 2003, 2003.03.. |
| 18. |
T. Kiss, M. Inoue, M. Yasunaga, K. Imamura, T. Ohta, Y. Iijima, K. Kakimoto, T. Saitoh, , Local resistive transition in YBCO coated tapes and global E-J characteristics, CSJ Conference, Vol. 68 (2003), 2003.03.. |
| 19. |
Takanobu Kiss, Transport E-J Characteristics in YBCO Coated Conductors (invited), The 11th International Workshop on Critical Currents in Superconductors (11th IWCC), 2003.07.. |
| 20. |
T. Kiss, M. Inoue, M. Yasunaga, K. Imamura, T. Ohta, H. Tokutomi, Y. Tsuda, H. Sawa and M. Takeo, Current Transport Properties in a YBCO Coated IBAD Tape Made by TFA-MOD Process, International Workshop on Coated Conductors for Application 2003 (CCA 2003), 2003.09.. |
| 21. |
T. Kiss, M. Yasunaga, Y. Murakami, H. Tokutomi, R. Okamoto, M. Inoue, M. Takeo, Non-uniform electric field distribution around a planar defect in YBCO film and its nfluence on thermal instability, 6th European Conference on Applied Superconductivity, 2003.09.. |
| 22. |
T. Kiss, M. Inoue, S. Egashira, M. Yasunaga, H. Tokutomi, M. Takeo, Y. Iijima, K. Kakimoto and T. Saitoh, Imaging of the local dissipation in YBCO coated tapes, Cryogenic Engineering Conference and International Cryogenic Materials Conference 2003, 2003.09.. |
| 23. |
Takanobu Kiss, Spatially resolved measurements of dissipative state in HTS tapes and films by low temperature scanning laser microscopy (invited), The 11th Japan-US Workshop on High-Tc Superconductors, 2003.10.. |
| 24. |
Takanobu Kiss, Fundamental Characteristics, 3rd meeting for US-Japan Collaboration Project of AC Loss, 2003.10.. |
| 25. |
T. Kiss, M. Yasunaga, H. Tokutomi, M. Inoue, M. Takeo, Electric field distribution around a transverse defect in an epitaxial YBCO thin film, CSJ Conference, Vol. 69 (2003), 2002.12.. |
| 26. |
T. Kiss, M. Inoue, M. Yasunaga, K. Imamura, T. Ohta, H. Tokutomi, Y. Tsuda, H. Sawa, M. Takeo, Y. Iijima, K. Kakimoto, T. Saitoh, Y. Tokunaga, T. Izumi and Y. Shiohara, Current transport properties in YBCO coated IBAD tapes, Asian Conference on Applied Superconductivity and Cryogenics, 2003.12.. |
| 27. |
Takanobu Kiss, Spatially resolved measurements of inhomogeneous dissipation in HTS conductors (Invited), 2004 International Cryogenic Materials Conference (ICMC) topical workshop, 2004.02.. |
| 28. |
T. Kiss，M. Yasunaga, H. Tokutomi, M. Inoue, M. Takeo, Measurement and analysis of local electric field concentration around an artificial plane defect in YBCO film, The 51st Spring Meeting 2004; The Japan Society of Applied Physics and Related Scieties, 2004.03.. |
| 29. |
T. Kiss, M. Inoue, H. Tokutomi, R. Okamoto, T. Shoyama, T. Imamura, Y. Iijima, K. Kakimoto, T. Saitoh, Y. Tokunaga, T. Izumi, and Y. Shiohara, Low temperature scanning laser microscopy of YBCO coated IBAD tapes, 106th Annual Meeting, The American Ceramic Society, 2004.04.. |
| 30. |
T. Kiss, Y. Murakami, R. Okamoto, S. Koyanagi, M. Inoue, M. Takeo, Y. Iijima, K. Kakimoto, T. Saitoh, Y. Shiohara, Laser imagining of local inhomogeneity in YBCO tapes covered by Ag-stabilization layer, CSJ Conference, Vol. 70 (2004), 2004.05.. |
| 31. |
T. Kiss, M. Inoue, K. Imamura, S. Koyanagi, M. Takeo, Y. Iijima, K. Kakimoto, T. Saitoh, Y. Shiohara, Imaging of trapped vortices in a YBCO coated conductor by scanning SQUID microscopy, The 65th Autumn Meeting, 2004; The Japan Society of Applied Physics, 2004.09.. |
| 32. |
T. Kiss, M. Inoue, H. Tokutomi, R. Okamoto, T. Shoyama, T. Imamura, Y. Iijima, K. Kakimoto, T. Saitoh, J. Matsuda, T. Izumi, and Y. Shiohara, Fundamental characteristics, US-Japan Collaboration: AC Loss Workshop, 2004.09.. |
| 33. |
Takanobu Kiss, Current Transport Properties in High-Temperature Superconducting Composites (Invited Keynote), The XXI Regional Conference and Workshop on Solid State Science & Technology, 2004.10.. |
| 34. |
T. Kiss, M. Inoue, M. Yasunaga, H. Tokutomi, Y. Iijima, K. Kakimoto, T. Saitoh, Y. Tokunaga, T. Izumi, Y. Shiohara, Low temperature scanning laser microscopy of YBCO coated IBAD tapes, Applied Superconductivity Conference, ASC 2004, 2004.10.. |
| 35. |
Takanobu Kiss, Microanalysis of superconducting properties in YBCO coated conductors (Invited), International workshop on coated conductors for applications, CCA 2004, 2004.11.. |
| 36. |
Takanobu Kiss, Recent topics on advances characterization of transport current in coated conductors (Invited), The 17th International Symposium on Superconductivity (ISS2004), 2004.11.. |
| 37. |
T. Kiss, M. Inoue, H. Tokutomi, S. Koyanagi, T. Shoyama, M. Takeo, Y. Shiohara, Nonlinear current flow around transverse defects in YBCO thin film, The 17th International Symposium on Superconductivity (ISS2004), 2004.11.. |
| 38. |
T. Kiss, M. Inoue, H. Tokutomi, T. Shoyama, S. Koyanagi, K. Imamura, M. Takeo, J. Matsuda, T. Izumi, Y. Shiohara, Influence of current limiting obstacles and nonlinear current flow in YBCO coated conductors, Asian Conference 2004 on Applied Superconductivity and Cryogenics (ACASC2004), 2004.11.. |
| 39. |
Takanobu Kiss, Spatially resolved measurements of local electromagnetic properties in YBCO coated conductors, US-Japan collaboration project on AC loss study of HTS conductor, 2005.03.. |
| 40. |
Takanobu Kiss, Imaging and Characterization of Nonuniform Current Transport in YBCO Coated Tapes (invited), MRS Spring meeting, 2005.04.. |
| 41. |
T. Kiss, M. Inoue, K. Imamura, H. Tokutomi, T. Shoyama, A. Ibi, T. Watanabe, Y. Yamada, Y. Shiohara, Imaging of non-uniform flux flow dissipation in YBCO/IBAD coated conductor under the influence of high magnetic field, CSJ Conference, Vol. 72 (2005), 2005.05.. |
| 42. |
Takanobu Kiss, Current transport properties in YBCO coated conductors under the influence of magnetic field and mechanical strain (Invited), 3rd Workshop on Mechano-Electromagnetic Property of Composite Superconductors (MEM05), 2005.07.. |
| 43. |
Takanobu Kiss, Laser imaging of non-uniform flux flow dissipation in YBCO coated conductors under the influence of external magnetic field (Invited), PacRim6 Symposium, Processing of High Temperature Superconductors, 2005.09.. |
| 44. |
Takanobu Kiss, Influence of Current Limiting Obstacles in YBCO Coated IBAD Conductors (Invited), The 12th US-Japan workshop on high performance superconductors, 2005.10.. |
| 45. |
Takanobu Kiss, Visualizing flux flow dissipation and current limiting obstacles in YBCO coated IBAD conductors (Invited talk), The 18th International Symposium on Superconductivity (ISS 2005), 2005.10.. |
| 46. |
T. Kiss, M. Inoue, T. Shoyama, T. Fujiwara, Z. Zulkifli，D. Mitsui, K. Imamura, M. Takeo, K. Ohmatsu, A. Ibi, Y. Yamada, Y. Shiohara, Novel visualizing technique for HTS grain structure in coated conductors by use of laser induced thermoelectric voltage, CSJ Conference, Vol. 73 (2005), 2005.11.. |
| 47. |
Takanobu Kiss, Combined multiple analysis of coated conductors for the understanding of current limiting mechanism (Invited talk), Seminar at Argonne National Laboratory, 2005.12.. |
| 48. |
Takanobu Kiss, Current limiting mechanism in IBAD based YBCO coated conductor (Invited talk), International Workshop on Coated Conductors for Applications (CCA), 2005.12.. |
| 49. |
Takanobu Kiss, Imaging and characterization of current transport in IBAD based YBCO coated conductors (Invited talk), Nano-Virtual-Labs Joint Workshop on Superconductivity (NVLS2005), 2005.12.. |
| 50. |
T. Kiss, M. Inoue, S. Koyanagi, T. Nakamura, K. Imamura, A. Ibi, Y. Yamada, Y. Shiohara, Current transport and dissipation in IBAD based coated conductors under the influence of local disorder, Asian Conference 2005 on Applied Superconductivity and Cryogenics, ACASC2005, 2005.12.. |
| 51. |
Takanobu Kiss, Development of multiple characterization techniques for the understanding of current limiting mechanism in HTS coated conductors (invited), Seminar at Korea Electrotechnology Research Institute, 2005.12.. |
| 52. |
T. Kiss, Processing and characterization of CC: Developments in Japan (Invited talk), The 2nd topical workshop of SCENET and the 11th CHEM-HTS workshop: Superconductivity, the Presnet and the Future, Illetas-Calvia, Mojorca, Spain, 2006.03.. |
| 53. |
T. Kiss, Development of multiple characterization techniques for the understanding of current limiting mechanism in coated conductors (Invited talk), Stanford-Wisconsin Workshop on Coated Conductors, 2006.04.. |
| 54. |
T. Kiss, Current limiting obstacles in IBAD based YBCO coated conductors: Finding a needle in a pile of hay (Invited talk), MRS 2006 Spring Meeting, 2006.04.. |
| 55. |
T. Kiss, M. Inoue, S. Koyanagi, T. Nakamura, T. Shoyama, K. Imamura, A. Ibi, S. Miyata, Y. Yamada, Y. Shiohara, Local I-V characteristic in YBCO coated conductor estimated by the combination of low temperature scanning laser microscopy and scanning SQUID microscopy, CSJ Conference, Vol. 74 (2006), 2006.05.. |
| 56. |
T. Kiss, Influence of Spatial Inhomogeneity of ac Susceptibility Technique to the Study of High-Temperature Superconductors, CCA (Organized by the European Network SCENET (Working Group Coated Conductors, with support of Working Group High Critical Current Superconductors)), 2006.07.. |
| 57. |
M. Inoue, T. Kiss, D. Mitsui, T. Nakamura, T. Fujiwara, S. Awaji, K. Watanabe, A. Ibi, S. Miyata, Y. Yamada, Y. Shiohara, Current transport properties of 200A-200m-class IBAD YBCO coated conductors over wide range of magnetic field and temperature, Applied Superconductivity Conference 2006, 2006.09.. |
| 58. |
T. Kiss, M. Inoue, T. Shoyama, S. Koyanagi, D. Mitsui, T. Nakamura, K. Imamura, A. Ibi, Y. Yamada, Y. Shiohara, Visualizing transport properties in IBAD based YBCO coated conductors by use of combined multiple analysis, 2006.09.. |
| 59. |
T. Kiss, Local inhomogeneity in IBAD based YBCO coated conductors (Invited talk), Materials Science and Technology 2006, 2006.10.. |
| 60. |
T. Kiss, Critical currents in YBCO coated conductors: The influence of spatial non-uniformity and flux pinning (Invited talk), The 19th International Symposium on Superconductivity (ISS 2006), 2006.10.. |
| 61. |
M. Inoue, K. Motoyama, T. Nakamura, T. Fujiwara, D. Mitsui, T. Kiss, S. Awaji, K. Watanabe, A. Ibi, K. Takahashi, S. Miyata, Y. Yamada, Y. Shiohara, Enhancement of Critical Current in YBCO Coated Conductors in Association with C-Axis Correlated Artificial Pinning Centers, The 19th International Symposium on Superconductivity (ISS 2006), 2006.10.. |
| 62. |
T. Nakamura, M. Inoue, T. Kiss, T. Watanabe, N. Kashima, M. Mori, S. Nagaya, A. Ibi, Y. Yamada, Y. Shiohara, Spatially Resolved Measurement of Current Flow in Multi-Filamentary YBCO Tape Wires,Tapes and Characterization, The 19th International Symposium on Superconductivity (ISS 2006), 2006.10.. |
| 63. |
T. Kiss, M. Inoue, T. Shoyama, D. Mitsui, T. Fujiwara, Z. Zulkifli，K. Imamura, M. Takeo, A. Ibi, Y. Yamada, Y. Shiohara, Current limiting mechanism in YBCO coated IBAD conductors, CSJ Conference, Vol. 75 (2006), 2006.11.. |
| 64. |
T. Kiss, R&D on advanced conductors and power applications in Japanese superconductivity national projects (Invited talk), Cermae, Energy Challenges: Materials for energy production, storage, distribution and efficiency, 2006.12.. |
| 65. |
T. Kiss, Development of novel characterization techniques for basic understanding of current limiting mechanisms in coated conductors (Invited lecture), Invited lecture at Institut de Ciencia de Materials de Barcelona (ICMAB), Universitat Autonoma de Barcelona, 2006.12.. |
| 66. |
Transport characteristics in Bi2223 wire fabricated by CT-OP process. |
| 67. |
Potential of High-Field Magnet Based on Critical Current Characteristics in Long GdBCO Coated Conductor. |
| 68. |
Overview of Development of Optimal Design Method for SMES Coil Using MOCVD-YBCO Conductor. |
| 69. |
Development of scanning Hall-probe microscope for the analysis of current transport in HTS tapes. |
| 70. |
Current transport in micro-filamentary and defect-repair-joining RE123 tapes. |
| 71. |
The use of LTLSM for estimating in-plane thermal diffusivity in YBCO thin films. |
| 72. |
Current transport in (001)-tilted YBCO bicrystalline film under the influence of external magnetic field. |
| 73. |
Observation of current distribution in high-Tc superconducting tape by using scanning hall-probe microscope. |
| 74. |
Coupled analysis method for high-field magnet coil using coated conductor based on J-E characteristics as a function of temperature, magnetic field vector and mechanical strain. |
| 75. |
Visualization of non-uniform current flow in coated conductors by scanning hall-probe magnetic microscopy. |
| 76. |
Critical current property in YBCO coated conductor fabricated by improved TFA-MOD process. |
| 77. |
Significant reduction in volume, stored energy and magnetization loss of high-field magneto coil based on the improvement of critical current characteristics in GdBCO coated conductor. |
| 78. |
Comprehensive analysis of current transport properties in RE1Ba2Cu3O7-d(RE=Y, Gd) coated conductors. |
| 79. |
Estimation of in-plane thermal diffusivity in YBCO bi-crystalline thin film by use of the low temperature laser scanning microscopy. |
| 80. |
Visualization of current profile in multi-filamentary model samples by the scanning Hall probe magnetic microscopy. |
| 81. |
Estimation of in-field axial strain dependence in RE123 coated conductors. |
| 82. |
Current distribution at repair joints made by silver diffusion soldering. |
| 83. |
Detection of inter-grain Jc at low angle bi-crystalline YBCO film across magnetic field induced crossover regime. |
| 84. |
Temperature，magnetic field and field angle dependence of critical current property in long length GdBCO coated conductor fabricated by RTR processcrossover regime. |
| 85. |
Electromagnetically-thermally-structurally coupled analysis of high-field magnet coil taking account of current transport characteristics in GdBCO coated conductor as a function of temperature， magnetic field， its angle and mechanical strain. |
| 86. |
Visualization of nonuniform current flow around a defect-repair-splicing in RE123 coated conductor. |
| 87. |
Critical currents and AC losses in coated conductors. |
| 88. |
Investigation of Hysteretic Characteristics in Multifilamentary Model Sample of YBCO Coated Conductor by Means of Magnetic Microscopy and Numerical Analysis. |
| 89. |
Visualization of the current distribution in multi-filamentary model samples by using the Hall-probe microscopy. |
| 90. |
Critical current property of mixed-system RE123 coated conductors fabricated by TFA-MOD process. |
| 91. |
T. Kiss, K. Higashikawa, M. Inoue, Recent Advancement of the Characterization Technology for Visualizing Local Electromagnetic Properties in Superconducting Forefront Materials (Invited), 2013 MRS Spring Meeting, 2013.04. |
| 92. |
Takanobu Kiss, Advancement and Future Prospects of RE-123 Coated Conductor Development in Japan (Invited), TCSHU Special Semina, 2013.07. |
| 93. |
T. Kiss, Evaluation of Local Electromagnetic Properties in Superconducting Forefront Materials for the Understanding of Current Limiting Mechanism (Invited), 16th US-Japan Workshop on Advanced Superconductors, 2013.07. |
| 94. |
T. Kiss, T. Izumi, Y. Iijima, Y. Shiohara, Recent advancement in laser processing of long-length high-performance RE-123 superconducting wires (Invited), The 14th International Symposium on Laser Precision Microfabrication (LPM 2013, part of LAMP 2013), 2013.07. |
| 95. |
T. Kiss, K. Higashikawa, M. Inoue, A. Ibi, T. Yoshida, T. Machi, M. Yoshizumi, T. Izumi
Y. Shiohara, K. Kimura, T. Koizumi, N. Aoki, T. Hasegawa, Y. Shingai, M. Konishi,
K. Ohmatsu, SPATIAL HOMOGENEITY OF LONG LENGTH RE-123 COATED CONDUCTORS (Invited), 26th Int. Sympo. on Superconductivity (ISS2013), 2013.11. |
| 96. |
T. Kiss, Challenges in RE-123 Coated Conductor Development–From the View Point of Electromagnetic Characterization– (Plenary talk), 27th Int'l Sympo. on Superconductivity (ISS2014), 2014.11. |
| 97. |
T. Kiss, K. Higashikawa, M. Inoue, H. Kitaguchi, Non-destructive characterization of local Ic variation in a long length Bi-2223 tape, Cryogenic Engineering Conference and International Cryogenic Materials Conference, 2015.06, Spatial homogeneity of critical current, Ic, is one of the most important performances of practical HTS tapes. Such Ic homogeneity is typically characterized by the reel-to-reel transport measurement with a tap distance of several tens cm to several m. However, the spatial resolution is not enough in the conventional method to detect local Ic drop, especially in the case of Bi-2223 tape because of a small shunt resistance of the Ag sheath. In this study, we have succeeded in measuring in-plane Ic distribution in a commercial 100-m-class Bi-2223 tape with non-contact and non-destructive manner by using reel-to-reel high speed scanning Hall probe microscopy. This allows us to measure high resolution remanent flux image on the tape surface in liquid nitrogen bath with a spatial resolution of 34 um in width and 830 um in length. Traveling speed of the tape during the measurement was 36 m/h at maximum. By solving the inversion problem, we obtained in-plane Ic distribution in the tape. We have succeeded in analyzing Ic fluctuation over multi-scale length more than 5 decades. To check the validity of the Ic value, we also carried out site-specified four-probe measurements, then confirmed that these two measurements showed good agreement each other. Statistical behavior of the Ic fluctuation and the correlation with microstructure will be discussed.
Acknowledgements: This study was supported by the “JST: S-Innovation” and "JSPS: KAKENHI (24360122)”.. |
| 98. |
T. Kiss, Measurement techniques for superconducting materials
, The 1st Japan-Korea Superconductivity Summer School, 2015.08. |
| 99. |
T. Kiss, M. Inoue, K. Higashikawa, K. Imamura, M. Yoshizumi, T. Izumi, Multi-Scale Hybrid Microscopy to Visualize Current Blocking Obstacles in a Long GdBCO Coated Conductor Tape, The 11th Pacific Rim Conference of Ceramic Societies, Symposium 20: Recent Advances in High Temperature Superconductors, 2015.09, To investigate the current limiting mechanism in a long coated conductor (CC) tape, we have developed hybrid microscopy technique combining reel-to-reel scanning Hall probe microscopy (RTR-SHPM) and X-ray microtomography (X-ray-CT). While the RTR-SHPM allows us to map a high resolution 2D critical current density (Jc) distribution in the tape surface up to 1 km of length with non-contact and non-destructive manner, the X-ray-CT can visualize 3D microstructure inside the tape with micro-meter resolution. Because the CC tape is essentially an 1D current transport media, a local bottleneck limits the performance of the whole CC tape. Namely, the bottleneck engineering becomes crucial to realize a high quality CC in a practical level. However, the present characterization techniques such as reel-to-reel transport measurement and 1D Hall mapping do not have enough spatial resolution to detect in-plane local obstacles in the tape. Furthermore, the relationship between a process condition and the limiting factor is not yet clear. In this study, we have succeeded in visualizing in-plane local Jc drop in a 200-m-long 5-mm-wide commercial GdBCO CC tape using the RTR-SHPM, that is followed by the X-ray-CT analysis to find out microstructural origin of the obstacles. Such hybrid microscopy clearly shows that the local Jc drop is originated from defects on the metal substrate. Note that this approach can cover 9 decades of multi-scale analysis from km to m range with correlating electromagnetic characterization and microstructural analysis. This is a powerful diagnostic tool to improve CC process conditions in a very effective way.
Acknowledgements: This work is supported by the Ministry of Economy, Trade and Industry (METI) as the Project for Development of HTS Coiling Technology and JSPS: KAKENHI (24360122).. |
| 100. |
Takanobu Kiss, Panelist for special session on numerical modeling for application: Remarks from the view point of materials characterization, EUCAS 2015, Round table: Modeling for applications, 2015.09. |
| 101. |
T. Kiss, T. Takahiro, K. Takasaki, K. Tanaka, M. Inoue, T. Kato, T. Izumi, Y. Shiohara, Influence of Highly Textured IBAD Based Template on In-Filed Current Transport Properties in Gd1Ba2Cu3O7-d Coated Conductors, 12th European Conference on Applied Superconductivity, EUCAS2015 , 2015.09, It is well established that in-plane alignment is essential to realize high critical current density in coated conductors (CCs) because of grain connectivity. It is also relevant to realize thick film deposition for the superconducting layers to increase overall critical current. The value of in-plane alignment, Df, of the substrate template is typically around 3 to 4 degree. However, the requirement for the substrate alignment is not yet fully understood especially in thick film and its performance. In this study, we have investigated the influence of highly textured IBAD based template on the in-filed current transport properties in Gd1Ba2Cu3O7-d (GdBCO) CCs. As a result of improved selfepitaxy of the CeO2 top layer, Df of the template can be reduced as low as 1.9 degree. We compared in-field critical currents of BaHfO3 doped 1.5 um-thick PLD-GdBCO deposited on such highly textured substrate and standard one, i.e., Df is 3.5 degree. From the analysis of critical current as a function of external magnetic field and temperature, we found that normalized pinning force density curves are scaled on the same curve for both case, however, the maximum value has increased 15 to 20 % for the case of highly textured substrate. This indicates that the nano-structures of the GdBCO layer are hardly influenced by the substrates, whereas effective cross-section area can be improved because of the reduction of current blocking obstacles in the case of highly textured substrate. From SEM observation of the GdBCO surface, it has been also confirmed that outer-growth can be suppressed effectively by using the highly textured substrate. These results show that the improvement of substrate in-plane alignment is still important and effective even in the range of DfAcknowledgements: This work is supported by the Ministry of Economy, Trade and Industry (METI) as the Project for Development of HTS Coiling Technology.
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| 102. |
T. Kiss, K. Higashikawa, M. Inoue, Takumi Suzuki, K. Imamura, Y. Onodera, D. Uetsuhara, K. Takasaki, A Ibi, T. Izumi, H. Kitaguchi, Comparison between RE-123 and Bi-2223 long length tapes from the view point of current transport properties influencing thermal stability
, International Workshop on Cooling System for HTS Application (IWC-HTS), 2015.10. |
| 103. |
T. Kiss, K. Higashikawa, K. Tanaka, K. Takasaki, K. Imamura, M. Inoue, S. Awaji, K. Watanabe, Teruo Izumi, Current Limiting Obstacles in a PLD Processed Commercial Long GdBCO Coated Conductor and Its Influence on In-Field Current Transport Properties
, International Conference on Magnet Technology 24 (MT24), 2015.10. |
| 104. |
Takanobu Kiss, Hybrid Microscopy Correlating Local Critical Current Variation and Filament Microstructure in MgB2 Round Wires
, 14th International Union of Materials Research Societies-International Conference on Advanced Materials (IUMRS-ICAM 2015) , 2015.10, Because of its round shape and a possible superconducting joint with the highest Tc as a metallic superconductor, MgB2 wire is one of the most promising materials to realize advanced devices such as a liquid He free MRI magnet. However, critical current density of the latest MgB2 wire is not yet high enough for practical application. Namely, it is crucial to clarify the current limiting mechanism in the round MgB2 wires. By combining low temperature scanning Hall probe microscopy (SHPM) and X-ray tomography, we have succeeded in studying correlation between spatial distribution of local critical current density, Jc, and three-dimensional (3D) microstructure of filaments in the wire with non-destructive manner. To realize spatially resolved Jc measurement on magnetic sheath wire, we adopted high field SHPM where we can obtain a magnetic image at an external field higher than the saturation field of the sheath. In parallel, internal filament structure has been investigated in a few mm range with a spatial resolution in m scale by using a high resolution X-ray tomography. 3D analysis by the tomography is powerful to understand internal microstructure of the filaments including defects, cross-sectional area and their statistical variation. Combination of these microscopies allows us to understand the origin of current limit factors such as distortion of the filaments and the difference of microstructure inside the filaments, and their relationship with processing. These analyses are very effective to improve wire performance.
This study is supported by the Japan Science and Technology Agency as Advanced Low Carbon Technology Research and Development Program (JST-ALCA) for Superconducting Systems.. |
| 105. |
T. Kiss, K. Higashikawa, M. Inoue, Takumi Suzuki, K. Imamura, Y. Onodera, D. Uetsuhara, K. Takasaki, H. Kitaguchi, A. Ibi, T. Machi, T. Izumi, Local Ic Fluctuation and Its Influence on Global Current-Voltage Characteristics in Long Length HTS Tapes (invited)
, 28th International Symposium on Superconductivity (ISS 2015), 2015.11, Spatial homogeneity in long length HTS tapes is one of the most important material performances for practical applications. While in-field current transport properties have been studied widely using short piece samples, local Ic fluctuation and its influence on global current transport properties in long length HTS tapes have not been understood yet. In this study, we carried out spatially resolved Ic measurements on long length HTS tapes, both RE-123 and Bi-2223, by the combination with multiple measurements including reel-to-reel high resolution scanning Hall probe microscopy (RTR-SHPM), four-probe measurements and X-ray tomography. We have investigated statistical behavior of local Ic fluctuation, local microstructural disorder and their influence on current-voltage (I-V) characteristics in the long length HTS tapes. From the analysis over wide range of length scale, the influence of spatial resolution of the measurements and sample length have been discussed from the view point of bandwidth of the spatial frequency, f. When the sample length becomes longer than several cm, the influence of 1/f type fluctuation becomes significant whereas the fluctuation is white noise type in short piece length. It has been shown that such long period fluctuation as 1/f influences transport I-V characteristics in long length tape. Relationship between observed longitudinal Ic distribution by the RTR-SHPM and global I-V characteristics has been derived. Not only monolithic tape strands but also multi-filamentary striated tapes have been studied. Influence of filament width on the Ic fluctuation has been discussed.
Acknowledgements: This work is supported by the AMED and the METI as a project of “Development of HTS Coiling Technology”, “JST: S-Innovation” and "JSPS: KAKENHI (24360122, 26630113).”. |
| 106. |
Takanobu Kiss, Nondestructive Characterization of Local Ic Variation in Long Bi-2223 Multi-filamentary Tapes and Correlated Study on Global Current-Voltage Characteristics (Plenary Talk)
, 8th Asian Conference on Applied Superconductivity and Cryogenics, 2015.11. |
| 107. |
T. Kiss, M. Inoue, K. Imamura, K. Takasaki, S. Awaji, K. Watanabe, A. Ibi, T. Yoshida, T. Izumi, Analytical Expression of In-Field Current Transport Properties in High- Tc Eu1Ba2Cu3O7-δ Coated Conductor Introduced with BaHfO3 Artificial Pinning Centers
, JSAP Kyushu Chapter Annual Meeting 2015, 2015.12. |
| 108. |
Takanobu Kiss, Multi-scale multi-physics analyses of forefront superconducting materials by use of hybrid microscopy (invited), 9th International Conference on Advanced Materials and Devices (ICAMD2015), 2015.12, One of the most important material parameters of superconductors is in-field critical current, Ic, which is the maximum current carried without electrical resistance. While the Ic is governed essentially by nanoscale defects due to flux pinning, current blocking obstacles in longer scale typically m to hundreds of m influence significantly. Such local inhomogeneity, however, cannot be detected by the standard characterization methods such as four probe transport measurement and magnetization measurement because they are both macroscopic measurements assuming sample homogeneity. Furthermore, as an engineering materials, superconducting wires are required to be reproducible with homogeneous performance in km scale. Therefore, multi-scale analysis becomes essential for understanding and resolving key performance issues of superconducting materials. In this study, we have developed novel characterization techniques, which include low temperature laser scanning microscopy, scanning SQUID microscopy and scanning Hall probe microscopy, for spatially resolved measurements of local electromagnetic properties. These techniques allow us to visualize local distribution of electric field, current density and fluxoid dynamics of forefront superconducting materials including Bi-2223 tape, RE-123 tape, MgB2 wire, and iron-base superconductors with high spatial resolution also in long length up to hundreds of meters. Furthermore, site-specified investigation coupled with microstructural analysis such as SEM, TEM and X-ray microscopy clearly shows the current limiting mechanism. These multi-scale multi-physics analyses are very useful to improve process conditions effectively.
Acknowledgements: This work is supported by the AMED and the METI as a project of “Development of HTS Coiling Technology”, “JST: S-Innovation”, “JST: ALCA” and "JSPS: KAKENHI (24360122, 26630113).”. |
| 109. |
Takanobu Kiss, Multi-scale modeling and analysis of current-voltage characteristics in long length HTS tapes (Invited), 26th Internatinoal Cryogenic Engineering Conference- International Cryogenic Materials Conference 2016 (ICEC26-ICMC2016), 2016.03. |
| 110. |
Takanobu Kiss, Recent progress of R&D on HTS technologies in Japan as potential breakthrough for electric power networks (invited), Seminar at KEPCO, 2016.03. |
| 111. |
Takanobu Kiss, Kohei Higashikawa, Masayoshi Inoue, Correlated Study of Local Ic Variation and Microstructural Disorder in a Bi-2223 Long Tape by Use of Hybrid Microscopy: Scanning Hall-Probe Microscopy and X-Ray Tomography, 2016 Materials Research Society Spring Meeting & Exhibit (2016 MRS Spring Meeting & Exhibit）, 2016.04. |
| 112. |
Takanobu Kiss, Masayoshi Inoue, Kohei Higashikawa, Teruo Izumi, Hiroaki Kumakura, Hybrid microscopy to visualize current blocking obstacles in forefront superconducting tapes and wires: RE-123 coated conductor, Bi-2223 multi-filamentary tape and MgB2 round wire (invited), 2016 Applied Superconductivity Conference (ASC 2016), 2016.09, Spatial homogeneity is one of the most important requirements for forefront superconducting tapes and wires. To screen out local Ic deterioration in long length HTS tapes, reel-to-reel transport measurement is often adopted with a voltage tap distance of around 1 m in commercial long tapes. In fact, recent commercial products achieved good longitudinal homogeneity with a standard deviation less than 1 % in a piece length of hundreds of meters. For a higher spatial resolution such as 1 mm or less, Hall probe array method is also often applied. They are both fast and useful diagnostic tools, however, essentially 1-dimensional measurements. Therefore, it is not possible to determine an in-plane position of a localized obstacles in the tape. Furthermore, no non-contact method is applicable so far for an iron-sheathed MgB2 round wire because of the magnetization of the sheath material. In this study, we carried out spatially resolved measurements on in-plane Ic drop in a long length RE-123 tape and Bi-2223, both hundreds of meters in length, with high spatial resolution (33 μm in width and 830 μm in length) non-contact non-destructive manner by use of fast scanning reel-to-reel Hall probe microscopy (RTR-SHPM). We have succeeded in detecting localized Ic drop in the long length tapes even though the probability of such drop is less than 0.1 %. To visualize local Ic variation in the iron-sheathed MgB2 round wire, we adopted in-field SHPM which allows us to observe a magnetic image at higher external field than a saturation field of the iron-sheath up to 5 T. From such high field measurement, we’ve succeeded in detecting local Ic variation non-destructive manner. To further understanding of such obstacles, we also carried out microstructural analysis by use of X-ray tomography. This allows us to visualize 3-dimensional internal structure with a spatial resolution of 2 μm. Correlated study between SHPM and X-ray tomography clearly showed the origin of the Ic drop such as obstacles in the substrate, distortion of filaments and clack formation. This can be a very effective diagnostic scheme to improve process conditions for forefront superconducting tapes and wires.. |
| 113. |
Takanobu Kiss, Kohei Higashikawa, Masayoshi Inoue, Takumi Suzuki, Hitoshi Kitaguchi, Teruo Izumi, Multi-scale analysis and modeling of current transport properties in long length HTS tapes under the influence of local Ic fluctuation, 2016 Applied Superconductivity Conference (ASC 2016), 2016.09. |
| 114. |
Takanobu Kiss, Spatially resolved measurements on critical currents in long length HTS tapes: Characterization techniques and related issues for standardization (invited), TC90 Mini-Workshop, 2016.09. |
| 115. |
Takanobu Kiss, Experience with Studies of the Positional Variation of Coated Conductor Properties (invited), Coated Conductors for Applications 2016 (CCA2016), 2016.09, Spatial homogeneity of superconducting properties such as critical current, Ic, n-index, effective tape (or filament) width is one of the most important requirements in coated conductors (CCs) as a reliable engineering materials. For example, a local Ic drop results in a significant enhancement of local electric field, which is several orders higher than that of average value, due to nonlinear current-voltage (I-V) characteristics. Indeed, we can often see an attached data sheet on spatial Ic variation as well as end-to-end Ic value at 77 K for a recent commercial long CC products. Several characterization techniques are proposed in a reel-to-reel manner for spatially resolved measurements of Ic in a long CC. Typically we can classify into two groups, i.e., transport measurement and magnetization measurements, and the latter can be divided into several methods including magneto optical imaging (MOI), Hall-probe array method (TapeStarTM), and scanning Hall-probe microscopy (SHPM). These characterization is relevant as a fundamental quality control for the CCs. However, each technique has quite different spatial resolution (along tape width or longitudinal direction) and electric-field criterion. As a result, the relationship among Ic values obtained by these methods is not yet fully understood. This means that the definition of the spatial homogeneity by using these measurements is not clear neither. Relationship between self-field (s.f.) Ic at 77 K and in-field Ic at low temperature is further important issue because the operation condition of the CCs is not usually 77 K, s.f. whereas lower temperature and higher field. In this talk, I will summarize reel-to-reel characterization techniques on critical currents in long CCs and discuss the influence of spatial resolution, sample length, and electric-field criterion. From the analysis of statistical behavior of the Ic distribution we found that the central limit theorem doesn’t hold in the case of CCs. This is a significant difference from a standard system which can be described by the Gaussian distribution, and must be originated from a strong non-linear relationship of the flux pinning which follows a threshold logic. We also derived a model to describe I-V characteristics, therefore positional variation of n-index, based on the local Ic variation. Validity of the model has been confirmed by the site-specified transport measurements. From in-field measurements on positional Ic variation up to 3 T of perpendicular field, we also show the influence of external magnetic on the correlation between 77 K Ic and low temperature Ic. Such in-field measurement has a good potential as a characterization method to optimize process conditions for nano-structured CCs with artificial pinning centers. Lastly, I will discuss the importance of 2-dimensional characterization of Ic distribution in processed tapes such as multi-filamentary tapes and Roebel strands for advanced applications. These results would be also important issues to be considered for standardization of the Ic characterization in long CCs.. |
| 116. |
Takanobu Kiss, Takahiro Fukuzaki, Shougo Ichimura, Yuta Onodera, Yuhei Nishimiya, Hiroaki Oofuji, Xiang Guo, Kazutaka Imamura, Takumi Suzuki, Kohei Higashikawa, Masayoshi Inoue, Shinji Fujita, Yasuhiro Iijima, Takato Machi, Akira Ibi, Teruo Izumi, Zhenan Jiang, Rodney Badcock, Nicholas Long, In-plane Distribution of Critical Current Density in Long Coated Conductor (invited), 1st Asian ICMC and CSSJ 50th Anniversary Conference, 2016.11, Spatial homogeneity of critical current density, Jc, is one of the most important requirements for practical coated conductors (CCs). Indeed, longitudinal Jc variation is usually characterized in a commercial CC by such method as reel-to-reel transport measurement and magnetization measurement by use of Hall-probe array as a typical method. However, the limiting factor of the positional Jc variation is not yet fully under stood because most of these measurements are essentially one-dimensional measurements. Namely, the spatial resolution along the transverse direction is not enough. Moreover, the behavior at in-field and lower temperature condition is relevant issue since most of the characterization so far is at around self-field (s.f.) and 77 K. In this study, we investigated in-plane distribution of local Jc in long CCs tape by reel-to-reel magnetic microscopy. From statistical analysis of the Jc distribution, we found that the probability density function shows a non-Gaussian type asymmetric distribution. Furthermore, the central limit theorem doesn’t hold. Based on these analysis, we proposed a multi-scale model to describe global current-voltage characteristics. We also succeeded in obtaining in-field Jc distribution up to 3 T of external magnetic field. From the in-field measurements, we investigated the influence of processing for artificial pinning center (APC) addition. The relative standard deviation increases slightly in the case we added APC as shown in Fig. 1. The influence of external magnetic field on the correlation between Jc at 77 K and that of lower temperature has also been studied. Lastly, the in-plane characterization in more complicated tape architectures such as multi-filamentary tape and Roebel strands has been carried out. Microstructural origin of current blocking obstacles has been investigated by site-specified analysis combined with the magnetic microscopy and X-ray micro-tomography.. |
| 117. |
Takanobu Kiss, Development of Characterization Techniques for Tailoring HTS Conductors as Engineering Materials (invited), Joint KU-VUW Workshop 2016 - Science, Engineering and Applications of Electric and Electronic Materials-, 2016.11. |
| 118. |
Takanobu Kiss, Kohei Higashikawa, Takumi Suzuki, Masayoshi Inoue, Teruo Izumi, Yasuhiro Iijima, Comparison among Spatially Resolved Measurements of Critical Currents in High- T
c Superconducting Long Tapes, The 1st Asian Applied Physics Conference, 2016.12. |
| 119. |
Takanobu Kiss, Kohei Higashikawa, Takahiro Fukuzaki, Yuta Onodera, Takumi Suzuki, Masayoshi Inoue, Takato Machi, Akira Ibi, Teruo Izumi, Statistical Behavior of Positional Variation Critical Current Density in Long RE-123 Coated Conductors, 29th International Symposium on Superconductivity (ISS2016), 2016.12. |
| 120. |
木須 隆暢, Development of Forefront Superconducting Materials for Next Generation Electric Energy Systems (invited), 2017.03, Development of Forefront Superconducting Materials for Next Generation Electric Energy Systems
Takanobu Kiss
Dept. of Electrical Engineering, Kyushu University, Fukuoka 819-0395, JAPAN
Superconducting materials can curry more than hundreds of times larger currents than that of normal conductors such as copper and aluminum with almost no dissipation. This allows us to realize high field magnets and/or high current cables. Indeed, superconducting technologies have already been utilized widely in such systems ad MRI, NMR, accelerator and nuclear fusion reactor. In the conventional superconducting devices, however, operation temperature is limited close to 4.2 K or lower realized with liquid helium. Namely, it requires complicated- and expensive-cooling systems. This prevents industrial applications of the superconducting technologies so far. Recent significant progress of cuprate superconductor tapes, however, have opened a new era of the superconducting technologies for industrial applications. This year is the 30 years anniversary of the discovery of Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O superconductors both exhibit superconductivity in liquid nitrogen temperature (77 K), i.e., critical-temperature (Tc) are >90 K, and >110 K, respectively. After the 30 years research and development, high performance long wires have been marketed. In this lecture, I will talk about the recent progress of high Tc cuprate superconductor tapes and their electric-power device applications. Challenges in other potential materials will also be mentioned. Our study focuses on understanding and resolving key performance issues of these forefront superconducting materials and their application to the advanced electric energy systems. Perspectives of these studies are to lead breakthrough to energy-efficiency solutions in electric grid systems, alternative energy and transportation systems.
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| 121. |
Takanobu Kiss, Kohei Higashikawa, Takumi Suzuki, Takahiro Fukuzaki, Daiki Tsujino, Yuta Onodera, Masayoshi Inoue, Description of temperature-, magnetic-field, and position-dependent current-voltage characteristics in high Tc superconducting long length coated conductors, CEC-ICMC 2017, 2017.07, In-field current transport property is one of the most important properties of high Tc superconducting tapes for practical applications. Usually the current-voltage (I-V) characteristics or critical current (Ic) are characterized by the four probe transport measurement or magnetization measurement using a short piece sample. In a practical application, however, the piece length of the tape strands reach more than hundreds of meters or km scale. This indicates that the influence of positional variation of Ic should also be taken into account to describe the I-V characteristics in a real device. In fact, the characterization of spatial Ic variation attracts much attention as a quality control of the long length tapes. However, the relationship between the spatial Ic variation and the local- and/or global-I-V characteristics are not well established. In this study, we have succeeded in measuring in-field Ic variation as a function of longitudinal coordinate, x, in reel-to-reel manner under external magnetic fields up to 4 T at 77 K and 65 K, respectively. We also obtained position-dependent I-V characteristics by site specified transport measurements using the same sample. We proposed an analytical model to describe the position-dependent I-V characteristics based on the Ic(x) in the long length tape. It has been shown that the analytical expression shows good agreement with the position-dependent in-field transport measurements. Namely, this approach allows us to describe the I-V characteristics as function of B, T, and x including position dependent n-index and localized flux flow dissipation in the long length tape.
Acknowledgements: This work was supported by “JSPS KAKENHI (16H02334)”.. |
| 122. |
Takanobu Kiss, Electrical Characterzation, The 2nd Asian Superconductivity Summer School (AS3 2017), 2017.08. |
| 123. |
Takanobu Kiss, Takumi Suzuki, Kohei Higashikawa, Takahiro Fukuzaki, Yuhei Nishimiya, Daiki Tsujino, Shohei Noda, Yuta Onodera, Masayoshi Inoue, Mitsunori Igarashi, Kazuomi Kakimoto, Yasuhiro Iijima, In-field Characterization of Local Ic and n-indices as a Function of Longitudinal Coordinate in a Long-length GdBCO Coated Conductor, International Conference on Magnet Technology 25 (MT25), 2017.08. |
| 124. |
Takanobu Kiss, HTS Tapes Development in Japan: Fundamentals and Recent Progress (invited), Special at Changwon National University, 2017.10. |
| 125. |
Takanobu Kiss, Yuta Onodera, Shohei Noda, Kohei Higashikawa, Kazutaka Imamura, Kohei Higashikawa, Takumi Suzuki, Masayoshi Inoue, Analysis of Magnetic Moment Relaxation in REBCO Coated Conductors by Use of Hall Probe Magnetometry, The 9th Asian Conference on Applied Superconductivity and Cryogenics (ACASC2017), 2017.11, Magnetic moment in coated conductor (CC) tape is an important issue from both fundamental and application point of view. Because of its flat monolithic architecture, a large magnetic moment is induced in the superconducting layer against perpendicular magnetic field component to the tape surface. Furthermore, such magnetic moment will decay significantly due to flux creep. These influence spatial homogeneity and temporal stability of magnetic field in CC based magnet windings. However, we can also use such magnetic moment to evaluate crucial electromagnetic parameters such as critical currents of the CC with non-contact and non-destructive manner. In typical measurements using magnetometer such as MPMS and VSM, we measure magnetic moment of the whole sample using pick up coil. We can collect, however, much more detailed information if we measure local magnetic field profile in the sample. In this study, we have investigated magnetic moment and its relaxation by use of Hall probe magnetometry. From the time dependent field distribution across the tape width, time evolution of local electric field distribution and a decay of shielding current were obtained based on Faraday’s law and Biot-Savart law, respectively. The results were also compared with that of critical state model and flux creep. One of the important advantages of the Hall probe measurement is to obtain the data including initial state of the flux creep less than 0.1 sec not only the long time relaxation. From these analysis, we have succeeded in obtaining electric field vs. critical current density (E-J) characteristics in the CC over 4 decades of electric fields from 10-6 to 10-10 V/m. Theoretical background for the derivation and comparison with other measurements such as four probe transport measurements and MPMS will be discussed.
Acknowledgment: This work was supported by JSPS: KAKENHI (16H02334).. |
| 126. |
Takanobu Kiss, Yuta Onodera, Shohei Noda, Kazutaka Imamura, Kohei Higashikawa, Takumi Suzuki, Masayoshi Inoue, Spatially Resolved Measurement on Local Electromagnetic Field Distribution in a Long Gd1Ba2Cu3O7-δ Coated Conductor during Magnetic Moment Relaxation by use of Hall Probe
Magnetometry, The 2nd Asian Applied Physics Conference, 2017.12. |
| 127. |
Takanobu Kiss, Fundamentals of Superconducting Wires and Tapes (invited), Superconductivity School 2017, 2017.12. |
| 128. |
Takanobu Kiss, Kohei Higashikawa, Takumi Suzuki, Yuhei Nishimiya, Yuta Onodera, Masayoshi Inoue, Mitsunori Igarashi, Kazuomi Kakimoto, Yasuhiro Iijima, Analysis and Modeling of Current Transport Properties in Long Length Coated Conductors(invited), 30th International Symposium on Superconductivity (ISS2017), 2017.12, Current-Voltage (I-V) characteristic is one of the most fundamental properties of superconducting materials for practical applications. While the I-V characteristics are usually measured by using a short piece sample and/or a micro-bridge, practical applications require long length tapes in hundreds of meters to several kilo-meters. Spatial homogeneity becomes an important issue in such cases because the minimum Ic will limit the total performance of the full-length of the tape. Therefore, Ic in the long length tape has been studied significantly as a function of longitudinal coordinate. However, it is not yet fully understood the relationship between the local Ic variation and the global I-V characteristics. In this study, we have investigated current transport properties in long length coated conductors (CCs) based on coupled analysis using reel-to-reel high-speed scanning Hall probe microscopy and site-specified transport measurements. An analytical model to describe the relationship between the local Ic variation and the global I-V characteristics in such long length CCs have been proposed. Furthermore, we will discuss a method to increase reliability, robustness and current carrying capability of the CCs under the influence of spatial Ic variation.
Acknowledgements: This work was supported by “JSPS KAKENHI (16H02334)” and “NEDO”.. |
| 129. |
Takanobu Kiss, Recent development of characterization techniques at KU for the development of forefront superconducting wires, 低温工学・超電導学会九州・西日本支部主催 著名外国人研究者による特別講演会, 2017.12. |
| 130. |
Takanobu Kiss, Development of Forefront Superconducting Wires for Next Generation Electric Energy System (Invited), Colloquium, Dept. of Physics, University of Ulsan, Korea , 2018.03. |
| 131. |
Takanobu Kiss, Shuhei Bouchi, Kohei Higashikawa, Masayoshi Inoue, Hiroaki Kumakura, Yanwei Ma , Hybrid Microscopy of MgB2 Round Wires: Combination with X-ray Tomography and Scanning Hall Probe Microscopy, 2018 MRS Spring Meeting & Exhibit, April 2-6, 2018, 2018.04, Combining X-ray tomography and in-field scanning Hall probe microscopy (SHPM), we have succeeded in visualizing local distortion of filaments at both PIT processed- as well as IMD processed-MgB2 wires and their influence on critical current distribution in the MgB2 wires. High resolution X-ray tomography is a powerful tool to investigate filamentary architecture and local distortion such as sausaging effect and exudation of Mg. From the magnetic image of the magnetized MgB2 wire measured by the SHPM, we could evaluate spatial distribution of local critical current density, Jc, according to Biot-Savart law. The in-field SHPM allows us to evaluate critical currents quantitatively of the MgB2 wire with magnetic sheath materials by the measurement where the external magnetic field is higher than the saturation field of the magnetic sheath [1]. The advantage of such magnetic measurements is also to evaluate high current region in which transport method is difficult to apply. Combination with the X-ray tomography and the SHPM leads abundant information on current limiting mechanism of the MgB2 wires by synergistic effect.
[1] K. Higashikawa et al., IEEE Trans. Appl. Supercond. 26 (2016) 6200804.
This study was supported by Japan Science and Technology Agency (JST) as ALCA.
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| 132. |
Takanobu Kiss, Challenges in characterization of superconducting properties in HTS tape strands and joints for NMR application, HTS線材の超電導接合・コイル技術に関するセミナー, 2018.04. |
| 133. |
Takanobu Kiss, Diagnostics and Jc-B Characteristics on Most Advanced Coated Conductor (invited), Lecture at Shanghai Superconductor Technology Co., Ltd (SSTC), 2018.05. |
| 134. |
Takanobu Kiss, Kohei Higashikawa, Takumi Suzuki, Issues in the Characterization of Current Transport Properties in REBCO Coated Conductors for Various Applications(invited), Shanghai High-Temperature Superconductor Conference 2018 （ShHTS2018）, 2018.08. |
| 135. |
Takanobu Kiss, Physical Properties of Superconducting Materials
, The 3nd Asian Superconductivity Summer School, AS3 2018), 2018.08. |
| 136. |
Takanobu Kiss, Significant improvement of robustness of current carrying capabilities in coated conductors by use of face-to-face double stacked architecture (invited), Coated Conductors for Applications 2018 (CCA2018), 2018.09, Spatial homogeneity of critical currents in coated conductors (CCs) is one of the most important issues for practical applications because the minimum Ic in a long length CC will limit the total performance of the tape. This becomes crucial especially in narrower and/or multi-filamentary tapes. In this study, we have investigated current transport properties in face-to-face double stacked (FFDS) CCs by measurements and analysis. Starting from a multi-scale modeling of nonlinear current transport properties in a long length CC strand, we developed a method to analyze detailed properties in the FFDS architecture including contact resistance, local electric field distribution and current sharing among the tapes. It has been shown that the total dissipation, i.e., joint resistance depends on Ic variation and its spatial frequency of the CCs. Based on the measurements on local Ic variation in a 1-mm-wide CC by the reel-to-reel scanning Hall probe microscopy, we analyzed the global current-voltage characteristics of the FFDS CCs at various conditions of joining resistance. Critical current density can be increased by a factor of two effectively and the local electric field concentration can be suppressed one order smaller than that of single strand even though at the same end-to-end voltage criterion of 1 uV/cm. From these analyses, we can lead the conclusion that the FFDS architecture is very effective to suppress the influence of local Ic drop and can improve the robustness and reliability of the CCs.
Acknowledgements: This work was supported by “JSPS KAKENHI (16H02334)” and partly by JST-Mirai Program Grant Number JPMJMI17A2, Japan.. |
| 137. |
Takanobu Kiss, Yuhei Nishimiya, Kohei Higashikawa, Takumi Suzuki, Masayoshi Inoue, Valery Petrykin, Sergey Lee, Kenji Suzuki, Masaru Tomita, Akira Ibi, Takato Machi, Teruo Izumi, Current transport properties in face-to-face double stacked narrow REBCO coated conductors under the influence of local Ic variation, 2018 Applied Superconductivity Conference (ASC 2018), 2018.10. |
| 138. |
Takanobu Kiss, Daiki Tsujino, Yukihisa Kumagai, Takumi Suzuki, Kohei Higashikawa, Valery Petrykin, Sergey Lee, Kenji Suzuki, Masaru Tomita, Akira Ibi, Takato Machi, Teruo Izumi, Analysis of current transport properties in a face-to-face double stacked coated conductors, The 3rd Asian Applied Physics Conference, 2018.12. |
| 139. |
Takanobu Kiss, Takumi Suzuki, Shohei Noda, Yuki Yamauchi, Kohei Higashikawa, Wataru Hirata, Shinji Fujita, Yasuhiro Iijima, Markus Bauer, Measurement and analysis of longitudinal Ic variation in long coated conductors fabricated by different processes: IBAD-PLD and ISD-coevaporation methods (invited), The 31st International Symposium of Superconductivity (ISS2018), 2018.12, Spatial homogeneity of critical current, Ic, in a long coated conductor (CC) is one of the most important requirements for practical applications of CC based devices. However, not only fundamental issues such as the origin of the spatial Ic variation and the influence of fabrication processes, but also a measurement method for the longitudinal Ic variation in the long CCs is not yet established as a standard method. In this study, we have carried out spatially resolved Ic measurements of long CCs by use of reel-to-reel magnetization measurements at 77 K self-field and also at 65 K in subcooled LN2 with applying external magnetic fields up to 2 T. Superconducting layers of the samples were deposited by 1) PLD method on an IBAD-MgO template, and 2) coevapolation method on an ISD-MgO template, respectively. In the former case, artificial pinning centers (APC) were also introduced using BaHfO3. It has been shown that behavior of the spatial Ic variation under external magnetic fields are similar even though the microstructures of the CCs are quite different from each other. Namely, positional dependence of the Ic is collapsed on a single curve if it is normalize by the average value of Ic at each magnetic field condition. This indicates that the spatial variation is almost independent from that of magnetic field dependence. This behavior is similar even in the case of APC doped CC in the IBAD-PLD process. This strongly suggests that the spatial Ic variation comes from macroscopic defects and not from the fluctuation of flux pinning behavior controlled by nano-scale defects. This was also confirmed from very similar APC nano-structures obtained by site-specified TEM observations at high- and low- Ic positions, respectively. Lastly, we considered the influence of spatial resolution and electric-field criterion on the Ic measurements in long CCs by typical two methods, i.e., magnetization measurement and transport measurement from the view point of standardization. Relationship between these two measurements has been discussed quantitatively.. |
| 140. |
Takanobu Kiss, Challenges in the characterization of current transport properties in HTS tapes for various applications (invited), Seminar at Changwon National University, 2019.02. |
| 141. |
Takanobu Kiss, Recent Progress in Development of Advanced Superconducting Materials in Japan and Outlook on Their Energy Applications (Invited), The 15th National Conference on Superconductivity, 2019.06, This lecture outlines the state of development of advanced superconducting materials, which is promoted in Japan by national projects, mainly from the viewpoint of the electromagnetic characterization developed by the authors, and also describes the energy application based on these materials. Superconducting materials that are currently being vigorously developed in Japan can be summarized on 1) RE-123 coated conductor, 2) Bi-2223 multi-filamentary tape, and 3) MgB2 multi-filamentary round wire. In addition to the wire developments, a new project on joining technology, which is also important as a basic technology for superconducting applications, has been launched. The application of these advanced superconducting materials is expected to realize a liquid helium-free magnet system, a superconducting liquid hydrogen hybrid energy system utilizing cryogenic heat of liquid hydrogen, and a railway electric cable system by liquid nitrogen cooling. In addition, the development of an ultra-high magnetic field NMR system exceeding 1 GHz has been promoted including the persistent current mode operation. In this lecture, novel characterization techniques and the methodology will be described for resolving key performance issues of these advanced superconducting wires which the authors have worked on. The future prospect of the energy applications based on these materials and requirement for the technological development for the next stage will also be discussed.
This study is supported partly by “JSPS KAKENHI (16H02334 , 24360122, 23760263)”, by the New Energy and Industrial Technology Development Organization (NEDO) and by JST-Mirai Program Grant Number JPMJMI17A2, Japan.. |
| 142. |
Takanobu Kiss, Kohei Higashikawa, Yukihisa Kumagai, Akihito Ide, Lin Lyu, Kazutaka Imamura, Wataru Hirata, Shinji Fujita, Yasuhiro Iijima, Enhancement of Measurement Speed over 100 m/h in Reel-to-Reel Scanning Hall Probe Microscopy Using a Multi-Channel Array (Invited), The 2019 Cryogenic Engineering Conference and International Cryogenic Materials Conference (CEC-ICMC 2019), 2019.07, In our previous study, we demonstrated that the reel-to-reel scanning Hall probe microscopy (RTR-SHPM) has a good advantage on the measurements of spatially resolved in-plane Jc distribution in a long length HTS tapes with a high spatial resolution along the tape width as well as the longitudinal direction. This is inevitable for a detection of localized defect in the tape, evaluation of an effective tape width, measurement of a very narrow tape and/or multi-filamentary tapes. However, one drawback of this method is its relatively low measurement speed around several tens meter per hour or less. In this study, we have succeeded in increasing the measurement speed significantly by introducing a multi-channel Hall probe array. Namely, we can increase the measurement speed N times faster by using a N-channel sensor array without loosing the spatial resolution. We demonstrated a measurement speed of 108 m/h with a longitudinal spatial resolution of 1 mm by using a 3-channel Hall probe array. From the comparison between the previous single channel measurement and the 3-channel measurement, we confirmed that the multi-channel measurement allows us to obtain the same quality Jc mapping with 3 times faster measurement speed. We can increase the measurement speed further just by increasing the numbers of the channels. Therefore, we believe that this method can be a practical diagnostics for a long length HTS tapes even in an industrial scale.
This work was supported by JSPS KAKENHI Grant Number 16H02334 and the New Energy and Industrial Technology Development Organization (NEDO).. |
| 143. |
Takanobu Kiss, Kohei Higashikawa, Shohei Noda, Yukihisa Kumagai, Takumi Suzuki, Kazutaka Imamura, Wataru Hirata, Shinji Fujita, Yasuhiro Iijima, Akira Ibi, Takato Machi, Teruo Izumi
, In-Field Current Transport Properties in Long Length IBADPLD REBCO Tapes under the Influence of Local Ic Variation, International Conference on Magnet Technology (MT26), 2019.09. |
| 144. |
Takanobu Kiss, Kohei Higashikawa, Shogo Ohta, Yusuke Takarabe, Kazutaka Imamura, Hideaki Miura, Shoichi Yokoyama, Novel Characterization Technique to Visualize Local Defects in a REBCO Pancake Coil Winding, International Conference
on Magnet Technology (MT26), 2019.09. |
| 145. |
Takanobu Kiss, Systematization of Characterization Technologies for Forefront Superconducting Materials Development (Invited), The First International Conference on Superconducting and Magnetic Technologies (SMT 2019), 2019.10. |
| 146. |
Takanobu Kiss, Characterization techniques for long length coated conductors and their pancake coil windings (Invited), The 3rd KU-VUW Workshop 2019, 2019.11. |
| 147. |
Takanobu Kiss, Yudai Onitsuka, Taiki Mori, Yuhki Yamauchi, Lin Lyu, Takumi Suzuki, Kohei Higashikawa, Modeling of current transport properties in long length high Tc conductors, The 4th Asian Applied Physics Conference (Asian-APC), 2019.11. |
| 148. |
Takanobu Kiss, Lin Lyu, Takumi Suzuki, Kohei Higashikawa, Local-vs.-Global Current-Voltage Characteristics in HTS Tapes , The 32nd Internatinal Symposium on Superconductivity (ISS2019), 2019.12. |
| 149. |
Takanobu Kiss, Kohei Higashikawa, Takumi Suzuki, Systematization of Characterization Techniques for High Tc Tape Strands and Coil Windings , The 10th Asian Conference on Applied Superconductivity and Cryogenics (ACASC), 2nd International Cryogenic Materials Conference in Asia (Asian-ICMC), and the CSSJ meeting (10th ACASC/2nd Asian-ICMC/CSSJ Joint Conference), 2020.01. |
| 150. |
Takanobu Kiss, Yudai Onitsuka, Zeyu Wu, Kohei Higashikawa,
Taketsune Nakamura, Takato Machi, Akira Ibi, Teruo Izumi, Systematization of Critical Current Evaluation Methods for Long Length High-Temperature
Superconducting Wires, The 5th Asian Applied Physics Conference (Asian-APC), 2020.11. |
| 151. |
Takanobu Kiss, Kenji Suzuki, Kohei Higashikawa, Masaru Tomita, Shigeru Sato, Solder-free flexible low resistance REBCO coated conductor joints realized by sound energy bonding process, The Virtual 2021 Joint 23rd Cryogenic Engineering Conference and International Cryogenic Materials Conference (CEC-ICMC 2021), 2021.07. |
| 152. |
Takanobu Kiss, Somjaijaroen Natthawirot, Kanta Yokoo, Kazutaka Imamura, Kohei Higashikawa, For More Robust and Reliable Coated Conductors (Invited), International Workshop on Coated Conductors for Applications 2021 (The Virtual 2021 CCA), 2021.10. |
| 153. |
KISS,Takanobu; TAKARABE,Yusuke; SHIGEOKA,Shun; WU,Zeyu; IMAMURA,Kazutaka; HIGASHIKAWA,Kohei; YOKOE,Daisaku; ITOH,Taishi; KATO,Takeharu; MIURA,Hideaki; HATTORI,Taisuke; OYA,Masayoshi; TONOOKA,Shun, Hybrid Microscopy to Clarify Failure Mechanisms of REBCO Tapes in Meter-Class Pancake-Coils, 27th International Conference on Magnet Technology (MT27), 2021.11. |
| 154. |
Takanobu Kiss, Peihong Zhang, Yuhsuke Oda, Keita Kawasaki, Zeyu Wu, Kenji Suzuki, Kohei Higashikawa, Shigeru Sato, Novel continuous bending test method applicable to a small diameter less than 10 mm and a development of flexible REBCO joints, 10th MEM Mechanical and Electromagnetic Properties of Composite Superconductors, 2022.07, In this study, bending properties of REBCO tapes and their joints have been investigated by a novel continuous bending property test method of small diameter, and we have succeeded in realizing excellent flexible joining to retain the initial Ic of 95 % or more at the minimum bending diameter of 6 mm. REBCO wire is much superior to BSCCO wire on bending property because of the thin film deposited on the thin substrate. However, the bending test of small diameter has not been sufficiently investigated due to the restriction of the size of the jig, etc. In this study, we proposed a novel bending test method in which REBCO tapes were bent in a loop. Based on image analysis of the loops, we found that the shape of the loop can be described by the clothoid curve in which the curvature linearly changes along the trajectory. This allows us to control the loop diameter by the sample length. Experimental results showed good agreement with that of theoretical analysis. Applying this bending test method, we examined bending characteristics of REBCO tape and bonded samples. While the critical bending diameter was 12 mm in the REBCO tape strand, the bonded samples showed excellent flexibility which surpassed the characteristics of the strand as the position of superconducting layer approaches closer to the neutral line in the bonded sample. We have achieved 6 mm in diameter as the minimum value in the joint.
Acknowledgements: This work was supported by JSPS KAKENHI Grant Number JP19H05617.. |
| 155. |
Takanobu Kiss, [Invited] Fundamentals of High-temperature Superconducting Tapes and Their Energy Applications, Tutorial Lecture, National Symposium on Cryogenics and Superconductivity 28（NSC28）, 2022.10. |
| 156. |
Takanobu Kiss, [Invited] Recent Advancement of Characterization Technologies to Improve the Quality of High‐Temperature Superconducting Wires and the Reliability of Coil Windings（基調講演）, National Symposium on Cryogenics and Superconductivity 28（NSC28）, 2022.10, Recent progress of high-temperature superconducting (HTS) wire is significant and commercially available 100’s-meters-class wires show superior homogeneity according to the standard characterization methods such as Hall probe array (TapeStarTM) measurements and/or reel-to-reel four probe measurements. However, the yield of coiling is still not high enough for practical applications especially in large scale HTS based magnets and the mechanism of the failure in the coil winding is not yet clarified. In this study, we have developed characterization techniques to visualize localized current blocking obstacles in long length HTS wires based on magnetic microscopy in conjunction with deep-learning based image analysis. This allows us to detect local obstacles in practical HTS wires and collect information on statistics including obstacle size distribution which were hardly possible to be obtained by the conventional local critical current criterion. In-field current transport properties have also been successfully measured in-situ operand conditions at extremely low electric-field range down to 10-12 V/m, which is inevitable as a base for superconducting magnets in NMR or MRI application. Obtained properties show good agreement with our theoretical model. Local degradation in pancake coil windings has also been visualized. This makes it possible to clarify the degradation mechanisms of the coil windings. Those insights based on the advanced characterization techniques are essential to improve practical HTS wire performances and the reliability of coiling the wires.
Acknowledgements: This work was supported by JSPS KAKENHI Grant Number JP19H05617.. |
| 157. |
Takanobu Kiss, Natthawirot Somjaijaroen, Mingyang Gao, Kazutaka Imamura, Zeyu Wu, Kohei Higashikawa, Advancement of magnetic microscopy by introducing deep-learning based image analyses for high performance characterization of REBCO coated conductors, 2022 The Applied Superconductivity Conference (ASC2022), 2022.10. |
| 158. |
Takanobu Kiss, Natthawirot Somjaijaroen, Kazutaka Imamura, Takuya Terazaki, Zeyu Wu, Kohei Higashikawa, [Invited] Automatic Detection of Local Inhomogeneity in REBCO Coated Conductor by High-Speed Reel-to-Reel Scanning Hall Probe Magnetic Microscopy Coupled with Machine Learning Based Image Analysis（招待講演）, 2022 International Forum on Applied Superconductivity and Magnetism, 2022.12. |
| 159. |
Zeyu Wu, Kohei Higashikawa, Natthawirot Somjaijaroen, Kazutaka Imamura, Takanobu Kiss, High-resolution Detection of Localized Jc inhomogeneity in long-length REBCO Coated Conductor by Combining Magnetic Microscopy and Deep Learning-based Object Detection, MT-28 International Conference on Magnet Technology, 2023.09. |
| 160. |
Zeyu Wu, K. Higashikawa, A. Queraltó, C. Pop, K. Gupta, X. Obradors, T. Puig, T. Kiss, Spatially Resolved Analysis of Local Jc in a Combinatorial Inkjet Printing for Transient LiquidAssisted Growth Chemical Solution Deposition, The 11th Asian Conference on Applied Superconductivity and Cryogenics / 3rd Asian International Cryogenic Materials Conference(ACASC-Asian ICMC 2023), 2023.10. |
| 161. |
Zeyu Wu, Kohei Higashikawa, Natthawirot Somjaijaroen, Kazutaka Imamura,Takanobu Kiss, Analysis of Current Blocking Obstacles in Long-length Coated Conductors by the Combination of High-Throughput Reel-to-Reel Magnetic Microscopy and Machine Learning, The 36th International Symposium on Superconductivity (ISS2023) , 2023.11. |
| 162. |
Takanobu Kiss, Yudai Onitsuka, Zeyu Wu, Kohei Higashikawa,
Taketsune Nakamura, Takato Machi, Akira Ibi, Teruo Izumi, Systematization of Critical Current Evaluation Methods for Long Length High-Temperature
Superconducting Wires, The 5th Asian Applied Physics Conference (Asian-APC), 2020.11. |
| 163. |
Zeyu Wu, Kohei Higashikawa, Takanobu Kiss, Continuous Measurement on Electric-field versus Current-density Characteristics in the Electric-field Window from 10-2 down to 10–11 V/m, 2022 The Applied Superconductivity Conference (ASC2022), 2022.10. |
| 164. |
Z. Wu, N. Somjaijaroen, K. Imamura, T. Terazaki, K. Higashikawa, T. Kiss, Automatic Detection of Ic Inhomogeneity in Long REBCO Tape Combining Deep Learningbased Object Detection and Magnetic Microscopy, The 7th Asian Applied Physics Conference (Asian-APC), 2022.11. |
