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Kin F, Itoh K, Bando T, Shinohara K, Oyama N, Terakado A, Yoshida M, Sumida S. Impact of avalanche type of transport on internal transport barrier formation in tokamak plasmas. Sci Rep 2023; 13:19748. [PMID: 37957265 PMCID: PMC10643559 DOI: 10.1038/s41598-023-46978-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 11/07/2023] [Indexed: 11/15/2023] Open
Abstract
In magnetic fusion plasmas, a transport barrier is essential to improve the plasma confinement. The key physics behind the formation of a transport barrier is the suppression of the micro-scale turbulent transport. On the other hand, long-range transport events, such as avalanches, has been recognized to play significant roles for global profile formations. In this study, we observed the impact of the avalanche-type of transport on the formation of a transport barrier for the first time. The avalanches are found to inhibit the formation of the internal transport barrier (ITB) observed in JT-60U tokamak. We found that (1) ITBs do not form in the presence of avalanches but form under the disappearance of avalanches, (2) the surface integral of avalanche-driven heat fluxe is comparable to the time rate change of stored energy retained at the ITB onset, (3) the mean E × B flow shear is accelerated via the ion temperature gradient that is not sustained under the existence of avalanches, and (4) after the ITB formation, avalanches are damped inside the ITB, while they remain outside the ITB.
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Affiliation(s)
- F Kin
- National Institutes for Quantum Science and Technology, Naka, 311-0193, Japan.
- Institute of Advanced Energy, Kyoto University, Uji, 611-0011, Japan.
| | - K Itoh
- Frontier Research Institute, Chubu University, Kasugai, 487-8501, Japan
- Research Center for Plasma Turbulence, Kyushu University, Kasuga, 816-8580, Japan
| | - T Bando
- Toyohashi University of Technology, Toyohashi, 441-8580, Japan
| | - K Shinohara
- National Institutes for Quantum Science and Technology, Naka, 311-0193, Japan
- The University of Tokyo, Kashiwa, 277-8561, Japan
| | - N Oyama
- National Institutes for Quantum Science and Technology, Naka, 311-0193, Japan
| | - A Terakado
- National Institutes for Quantum Science and Technology, Naka, 311-0193, Japan
| | - M Yoshida
- National Institutes for Quantum Science and Technology, Naka, 311-0193, Japan
| | - S Sumida
- National Institutes for Quantum Science and Technology, Naka, 311-0193, Japan
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Terakado A, Koide Y, Yoshida M, Nakano T, Homma H, Oyama N. Design of Heat-Resistant in-Vessel Components for Deuterium Beam-Aided Charge Exchange Recombination Spectroscopy in JT-60SA. Fusion Science and Technology 2022. [DOI: 10.1080/15361055.2021.1951529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- A. Terakado
- National Institutes for Quantum and Radiological Science and Technology, Naka, Ibaraki 311-0193, Japan
| | - Y. Koide
- National Institutes for Quantum and Radiological Science and Technology, Naka, Ibaraki 311-0193, Japan
| | - M. Yoshida
- National Institutes for Quantum and Radiological Science and Technology, Naka, Ibaraki 311-0193, Japan
| | - T. Nakano
- National Institutes for Quantum and Radiological Science and Technology, Naka, Ibaraki 311-0193, Japan
| | - H. Homma
- National Institutes for Quantum and Radiological Science and Technology, Naka, Ibaraki 311-0193, Japan
| | - N. Oyama
- National Institutes for Quantum and Radiological Science and Technology, Naka, Ibaraki 311-0193, Japan
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Kin F, Nakano T, Oyama N, Terakado A, Wakatsuki T, Narita E. Prediction of a single Gaussian shape of spectral line measured with low-dispersion spectrometer by using machine learning. Rev Sci Instrum 2021; 92:053505. [PMID: 34243237 DOI: 10.1063/5.0039781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 04/10/2021] [Indexed: 06/13/2023]
Abstract
We have developed a denoising autoencoder based neural network (NN) method to determine a spectral line intensity with an uncertainty lower than the uncertainty determined by fitting the spectral line. The NN method processes the measured raw spectral line shape, providing a single Gaussian shape based on the training dataset, which consists of synthetically prepared Doppler shift and broadening free spectral lines in the present work. It is found that the uncertainty reduction level significantly depends on the training dataset. Limitations originating from the training dataset are also discussed.
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Affiliation(s)
- F Kin
- National Institutes for Quantum and Radiological Science and Technology, 801-1 Mukoyama, Naka, Ibaraki 311-0193, Japan
| | - T Nakano
- National Institutes for Quantum and Radiological Science and Technology, 801-1 Mukoyama, Naka, Ibaraki 311-0193, Japan
| | - N Oyama
- National Institutes for Quantum and Radiological Science and Technology, 801-1 Mukoyama, Naka, Ibaraki 311-0193, Japan
| | - A Terakado
- National Institutes for Quantum and Radiological Science and Technology, 801-1 Mukoyama, Naka, Ibaraki 311-0193, Japan
| | - T Wakatsuki
- National Institutes for Quantum and Radiological Science and Technology, 801-1 Mukoyama, Naka, Ibaraki 311-0193, Japan
| | - E Narita
- National Institutes for Quantum and Radiological Science and Technology, 801-1 Mukoyama, Naka, Ibaraki 311-0193, Japan
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Terakado A, Sakamoto M, Ezumi N, Nojiri K, Mikami T, Kinoshita Y, Togo S, Iijima T, Sawada K, Kado S, Nakashima Y. Reaction processes of molecular activated recombination leading to detachment of divertor simulation plasma in GAMMA 10/PDX. Nuclear Materials and Energy 2019. [DOI: 10.1016/j.nme.2019.100679] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Ichimura K, Fukumoto M, Islam MM, Islam MS, Shimizu K, Fukui K, Ohuchi M, Nojiri K, Terakado A, Yoshikawa M, Ezumi N, Sakamoto M, Nakashima Y. Measurement of neutral gas pressure in the D-module of GAMMA 10/PDX by using ASDEX type fast ionization gauge. Rev Sci Instrum 2016; 87:11D424. [PMID: 27910550 DOI: 10.1063/1.4960536] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In the divertor simulation experiments in the GAMMA 10/PDX tandem mirror, pressure of the neutral gas was investigated by using a fast ionization gauge. The gauge was absolutely calibrated for hydrogen gas by using a capacitance manometer. Change of the gauge sensitivity due to the magnetic field of GAMMA 10/PDX was also evaluated. The typical gas pressure measured in detached plasma experiments was 0.1-10 Pa. The degree of plasma detachment determined from the reduction of heat flux was enhanced as the gas pressure increases. Rapid increase of the gas pressure under the plasma flow was also observed.
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Affiliation(s)
- K Ichimura
- Plasma Research Center, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan
| | - M Fukumoto
- National Institutes for Quantum and Radiological Science and Technology, 801-1 Mukouyama, Naka, Ibaraki, Japan
| | - M M Islam
- Plasma Research Center, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan
| | - M S Islam
- Plasma Research Center, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan
| | - K Shimizu
- Plasma Research Center, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan
| | - K Fukui
- Plasma Research Center, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan
| | - M Ohuchi
- Plasma Research Center, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan
| | - K Nojiri
- Plasma Research Center, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan
| | - A Terakado
- Plasma Research Center, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan
| | - M Yoshikawa
- Plasma Research Center, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan
| | - N Ezumi
- Plasma Research Center, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan
| | - M Sakamoto
- Plasma Research Center, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan
| | - Y Nakashima
- Plasma Research Center, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki, Japan
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Nojiri K, Sakamoto M, Oki K, Yoshikawa M, Nakashima Y, Yoshikawa M, Terakado A, Nohara R, Mizuguchi M, Imai T, Ichimura M. Relation between Electron Density and Temperature of Divertor Simulation Plasma and Upstream Plasma in GAMMA 10/PDX. Fusion Science and Technology 2015. [DOI: 10.13182/fst14-893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- K. Nojiri
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - M. Sakamoto
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - K. Oki
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - M. Yoshikawa
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Y. Nakashima
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - M. Yoshikawa
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - A. Terakado
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - R. Nohara
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - M. Mizuguchi
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - T. Imai
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - M. Ichimura
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
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Oki K, Sakamoto M, Nakashima Y, Yoshikawa M, Nohara R, Nojiri K, Terakado A, Mizuguchi M, Ichimura K, Takeda H, Iwamoto M, Hosoda Y, Shimizu K, Yoshikawa M, Kohagura J, Imai T, Ichimura M. Electron Temperature and Density Distributions in a Divertor Simulation Experimental Module with Gas Injection in GAMMA 10/PDX. Fusion Science and Technology 2015. [DOI: 10.13182/fst14-896] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- K. Oki
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - M. Sakamoto
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Y. Nakashima
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - M. Yoshikawa
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - R. Nohara
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - K. Nojiri
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - A. Terakado
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - M. Mizuguchi
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - K. Ichimura
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - H. Takeda
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - M. Iwamoto
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Y. Hosoda
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - K. Shimizu
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - M. Yoshikawa
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - J. Kohagura
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - T. Imai
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - M. Ichimura
- University of Tsukuba, Plasma Research Center, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
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Kon T, Yamazaki M, Tagawa M, Goto S, Terakado A, Moriya H, Fujimura S. Bone morphogenetic protein-2 stimulates differentiation of cultured spinal ligament cells from patients with ossification of the posterior longitudinal ligament. Calcif Tissue Int 1997; 60:291-6. [PMID: 9069168 DOI: 10.1007/s002239900231] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Ossification of the posterior longitudinal ligament (OPLL) of the spine is characterized by heterotopic bone formation occurring in spinal ligament, causing severe compression myelopathy. In order to investigate the mechanism of OPLL development, we isolated spinal ligament cells from OPLL patients as well as non-OPLL patients, and established 10 OPLL cell lines and 7 non-OPLL cell lines, respectively. We analyzed the effects of bone morphogenetic protein-2 (BMP-2) on these cells with respect to alkaline phosphatase (AP) activity, DNA synthesis, and collagen production. BMP-2 caused a significant increase of AP activity in 4 OPLL cell lines, whereas the activity did not change in any non-OPLL cells. Among OPLL cells, BMP-2 stimulated DNA synthesis in four cell lines and procollagen type I carboxyl-terminal peptide (PICP) synthesis in five cell lines. Some non-OPLL cells also responded to BMP-2, as there was an increase of DNA synthesis in three cell lines and PICP synthesis in one cell line. These data collectively indicate that BMP-2 preferentially induces osteogenic differentiation in OPLL cells rather than in non-OPLL cells. OPLL cells, therefore, exhibit a different response to BMP-2 than non-OPLL cells, suggesting that the expression of BMP receptor(s) and/or the signal transduction initiated by BMP-2 in the spinal ligament cells of OPLL patients somewhat deviate from those in normal spinal ligament cells. Such abnormal characteristics of OPLL cells as described here provide some clues to the clarification of the pathogenesis of OPLL.
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Affiliation(s)
- T Kon
- Department of Orthopaedic Surgery, School of Medicine, Chiba University, Japan
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Terakado A, Tagawa M, Goto S, Yamazaki M, Moriya H, Fujimura S. Elevation of alkaline phosphatase activity induced by parathyroid hormone in osteoblast-like cells from the spinal hyperostotic mouse TWY (twy/twy). Calcif Tissue Int 1995; 56:135-9. [PMID: 7736322 DOI: 10.1007/bf00296345] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We have examined the alkaline phosphatase (AP) activity of primary calvaria-derived osteoblast-like cells from the twy (tip-toe walking Yoshimura) and normal ICR control mouse. The twy mouse displays elevated osseous formation particularly in the spine, and the pathophysiological features resemble that of human ankylosing spinal hyperostosis. In the proliferative stage of cultured bone cells, parathyroid hormone (PTH) stimulation induced the elevation of AP activity of both twy and ICR mouse-derived cells. When they reached confluence, the AP activity of ICR mouse-derived cells ceased to increase with PTH stimulation. The twy mouse-derived cells, however, continued to respond to PTH, with the enzyme activity increasing even in the confluent, stationary stage. PTH stimulation also increased the intracellular cAMP content of twy mouse-derived cells but it did not influence that of ICR mouse-derived cells in the stationary stage. Moreover, stimulation with dibutyryl cAMP, but not with phorbol myristate acetate, increased the AP activity of both twy and ICR-derived bone cells irrespective of culture conditions, either in the proliferative or in the confluent stage. These data suggest that the protein kinase A-mediated pathway plays a pivotal role in bone cells with PTH stimulation, and that the uninhibited AP activity observed in twy mouse-derived bone cells might be due to some deviating process between the PTH ligand/receptor interaction and cAMP generation.
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Affiliation(s)
- A Terakado
- Department of Orthopaedic Surgery, School of Medicine, Chiba University, Japan
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