A cylindrical carbon pellet with a size of 1.0 mm φ × 1.0 mm L was injected into low-density (ne = 0.3‐0.5 × 10 13 cm -3 ) neon-seeded NBI plasmas of the Large Helical Device (LHD). When the two NBI beam pulses were delayed just after the pellet injection, a large increment of central ion temperature up to 5 keV was observed with the appearance of a peaked density profile (ne0 /〈ne〉~2.5) and enhanced toroidal rotation speed up to 35 km/s. Improvement of the ion transport is expected with the suggestion of a new operational scenario for confinement improvement in the LHD.
将尺寸为1.0 mm φ × 1.0 mm L的圆柱形碳球注入大螺旋装置(LHD)的低密度(ne = 0.3‐0.5 × 10 - 13 cm -3)氖种子NBI等离子体中。当两束NBI脉冲在球团注入后延迟时，观察到中心离子温度大幅增加至5 keV，出现峰值密度分布(ne0 / < ne > ~2.5)，环形旋转速度增强至35 km/s。离子输运的改善是预期的，并提出了一种新的操作方案，以改善LHD的约束。
{"title":"Increase of Central Ion Temperature After Carbon Pellet Injection in Ne-Seeded NBI Discharges","authors":"Morita Shigeru, Nozato Hideaki, Takeiri Yasuhiko, Goto Motoshi, Ikeda Katsunori, Inagaki Shigeru, Kaneko Osamu, Kawahata Kazuo, Miyazawa Jyun-ichi, Muto Sadatsugu, Mutoh Takashi, Nagaoka Kenichi, Nagayama Yoshio, Oka Yoshihide, Osakabe Masaki, Sakakibara Satoru, Sakamoto Ryuichi, T. Kenji, Tokuzawa Tokihiko, Tsumori Katsuyoshi, Yamada Hiroshi","doi":"10.1585/JSPF.79.641","DOIUrl":"https://doi.org/10.1585/JSPF.79.641","url":null,"abstract":"A cylindrical carbon pellet with a size of 1.0 mm φ × 1.0 mm L was injected into low-density (ne = 0.3‐0.5 × 10 13 cm -3 ) neon-seeded NBI plasmas of the Large Helical Device (LHD). When the two NBI beam pulses were delayed just after the pellet injection, a large increment of central ion temperature up to 5 keV was observed with the appearance of a peaked density profile (ne0 /〈ne〉~2.5) and enhanced toroidal rotation speed up to 35 km/s. Improvement of the ion transport is expected with the suggestion of a new operational scenario for confinement improvement in the LHD.","PeriodicalId":7974,"journal":{"name":"Annual Report of National Institute for Fusion Science","volume":"115 ","pages":"5"},"PeriodicalIF":0.0,"publicationDate":"2003-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91452591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Emoto, M. Watanabe, S. Masuzaki, N. Ohno, H. Okada
Smooth cooperative research requires effective remote participation. Toward this end, the National Institute for Fusion Science (NIFS) has enhanced its network among domestic institutes. The new network, called the Super Science information network (SINET), connects national universities and governmental organizations and has a 10 G bps backbone. NIFS connected Kyoto University and Nagoya University to this network at a speed of 1 G bps each way in 2002, and plans to connect other universities. In addition, a real-time video streaming system is being developed for remote participation in this network. Due to bandwidth limitations of the network, lossy motion image formats, such as Real Video or MPEG, are widely used for video streaming service. For example, the minimum transfer ratio to send a VGA-sized video image at the rate of 30 fps is 27 MB/s, or 220 M bps, which exceeds ordinal network capacities. However, lossy images cannot be used for physical analysis, because the original information is lost. N...
{"title":"High Quality Video Streaming System for Plasma Diagnostic Using Super SINET","authors":"M. Emoto, M. Watanabe, S. Masuzaki, N. Ohno, H. Okada","doi":"10.1063/1.1534923","DOIUrl":"https://doi.org/10.1063/1.1534923","url":null,"abstract":"Smooth cooperative research requires effective remote participation. Toward this end, the National Institute for Fusion Science (NIFS) has enhanced its network among domestic institutes. The new network, called the Super Science information network (SINET), connects national universities and governmental organizations and has a 10 G bps backbone. NIFS connected Kyoto University and Nagoya University to this network at a speed of 1 G bps each way in 2002, and plans to connect other universities. In addition, a real-time video streaming system is being developed for remote participation in this network. Due to bandwidth limitations of the network, lossy motion image formats, such as Real Video or MPEG, are widely used for video streaming service. For example, the minimum transfer ratio to send a VGA-sized video image at the rate of 30 fps is 27 MB/s, or 220 M bps, which exceeds ordinal network capacities. However, lossy images cannot be used for physical analysis, because the original information is lost. N...","PeriodicalId":7974,"journal":{"name":"Annual Report of National Institute for Fusion Science","volume":"29 1","pages":"168"},"PeriodicalIF":0.0,"publicationDate":"2003-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75544480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
U. Safronova, Y. Ralchenko, I. Murakami, T. Kato, D. Kato
We calculate energy levels, radiative transition probabilities, and autoionization rates for Be-like oxygen (O 4+ ) including 1s 2 2lnl � (n = 2-8, l ≤ n − 1) and 1s 2 3lnl (n = 3-6, l ≤ n − 1) states by the multiconfigurational Hartree-Fock method (Cowan code) and the perturbation theory Z-expansion method (MZ code). The state selective dielectronic recombination-rate coefficients to excited states of Be-like oxygen are obtained, which are useful for modeling O V spectral lines in a recombining plasma. Configuration mixing plays an important role for the principal quantum number, n, distribution of the dielectronic recombination-rate coefficients for 2snl (n ≤ 5) levels at low electron temperature. The orbital angular momentum quantum number, l, distribution of the rate coefficients shows a peak at l = 4. The total dielectronic recombination-rate coefficient is derived as a function of electron temperature. The dielectronic satellite lines are also obtained.
{"title":"Dielectronic Recombination Rate Coefficients to Excited States of Carbonlike Oxygen and Dielectronic Satellite Lines","authors":"U. Safronova, Y. Ralchenko, I. Murakami, T. Kato, D. Kato","doi":"10.1139/P02-079","DOIUrl":"https://doi.org/10.1139/P02-079","url":null,"abstract":"We calculate energy levels, radiative transition probabilities, and autoionization rates for Be-like oxygen (O 4+ ) including 1s 2 2lnl � (n = 2-8, l ≤ n − 1) and 1s 2 3lnl (n = 3-6, l ≤ n − 1) states by the multiconfigurational Hartree-Fock method (Cowan code) and the perturbation theory Z-expansion method (MZ code). The state selective dielectronic recombination-rate coefficients to excited states of Be-like oxygen are obtained, which are useful for modeling O V spectral lines in a recombining plasma. Configuration mixing plays an important role for the principal quantum number, n, distribution of the dielectronic recombination-rate coefficients for 2snl (n ≤ 5) levels at low electron temperature. The orbital angular momentum quantum number, l, distribution of the rate coefficients shows a peak at l = 4. The total dielectronic recombination-rate coefficient is derived as a function of electron temperature. The dielectronic satellite lines are also obtained.","PeriodicalId":7974,"journal":{"name":"Annual Report of National Institute for Fusion Science","volume":"5 1","pages":"405"},"PeriodicalIF":0.0,"publicationDate":"2002-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86082593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Haruyama, N. Kimura, H. Nakai, T. Shintomi, M. Shiotsu, Y. Shirai, K. Hata, A. Sato, Michinari Yuyama, M. Maeda, T. Mito, N. Yanagi, R. Maekawa, A. Iwamoto, S. Hamaguchi
A grant-in-aid project on the database development for He II-cooled superconducting magnet system design has been going on as a 3-year project. Many big projects on He II cooled superconducting magnets and cavities have been planned and are under construction around the world. He II systems consist of many specific technologies such as helium heat transfer coefficients under pressurized and saturated superfluid helium conditions, cooling characteristics in micro channels, Kapitza resistance between the surface of heat exchanger, helium pumping techniques, in situ measurement of temperature, pressure under high magnetic fields, and so on. The four organizations including university and national institutes started their collaborative research on this project to develop a convenient and useful database system. Two activities are going on: The first is to pick up the related papers already published in journals and proceedings in cryogenics and superconductivity fields from 1970. The second is to carry out the original experimental researches on He II technologies to obtain new data and to obtain more accurate and reliable data. As for the first sources, we have already picked up about 1, 000 papers and have carried out several experiments. This paper describes the present situation on this research project on the He II database and future plan.
{"title":"Database Development for He II-cooled Superconducting Magnet System Design","authors":"T. Haruyama, N. Kimura, H. Nakai, T. Shintomi, M. Shiotsu, Y. Shirai, K. Hata, A. Sato, Michinari Yuyama, M. Maeda, T. Mito, N. Yanagi, R. Maekawa, A. Iwamoto, S. Hamaguchi","doi":"10.2221/JCSJ.36.671","DOIUrl":"https://doi.org/10.2221/JCSJ.36.671","url":null,"abstract":"A grant-in-aid project on the database development for He II-cooled superconducting magnet system design has been going on as a 3-year project. Many big projects on He II cooled superconducting magnets and cavities have been planned and are under construction around the world. He II systems consist of many specific technologies such as helium heat transfer coefficients under pressurized and saturated superfluid helium conditions, cooling characteristics in micro channels, Kapitza resistance between the surface of heat exchanger, helium pumping techniques, in situ measurement of temperature, pressure under high magnetic fields, and so on. The four organizations including university and national institutes started their collaborative research on this project to develop a convenient and useful database system. Two activities are going on: The first is to pick up the related papers already published in journals and proceedings in cryogenics and superconductivity fields from 1970. The second is to carry out the original experimental researches on He II technologies to obtain new data and to obtain more accurate and reliable data. As for the first sources, we have already picked up about 1, 000 papers and have carried out several experiments. This paper describes the present situation on this research project on the He II database and future plan.","PeriodicalId":7974,"journal":{"name":"Annual Report of National Institute for Fusion Science","volume":"32 1","pages":"103"},"PeriodicalIF":0.0,"publicationDate":"2001-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87025102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Muroga, K. Yasunaga, Y. Katoh, Hideo Watanabe, N. Yoshida, N. Noda
{"title":"Correlation of Hardening and Microstructure of Tantalum Irradiated with Heavy Ions","authors":"T. Muroga, K. Yasunaga, Y. Katoh, Hideo Watanabe, N. Yoshida, N. Noda","doi":"10.1520/STP12463S","DOIUrl":"https://doi.org/10.1520/STP12463S","url":null,"abstract":"","PeriodicalId":7974,"journal":{"name":"Annual Report of National Institute for Fusion Science","volume":"97 1","pages":"60"},"PeriodicalIF":0.0,"publicationDate":"2000-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76032606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Nomura, T. Osaki, S. Takahashi, Yoshihisa Sato, R. Shimada, S. Yamaguchi, H. Chikaraishi, O. Motojima, T. Takao, A. Ninomiya
Superconducting conductors which are composed of many superconducting strands have a problem of current imbalance. This may cause the conductors to quench at a current level below its design value. This paper proposes the iron core methods to fix the current imbalance problem. The iron core method is the one in which two insulated strands are passed through an iron core with electric currents circulating in opposite directions. We investigated the current imbalance by using Ag sheathed Bi-2223 high temparature superconducting wire. We observed that the current imbalance was corrected by using ferrite iron core in liquid nitrogen. Finally, we discuss the size of iron core needed to solve the current imbalance problem.
{"title":"Experiment of Current Imbalance Correction Using Iron Core","authors":"S. Nomura, T. Osaki, S. Takahashi, Yoshihisa Sato, R. Shimada, S. Yamaguchi, H. Chikaraishi, O. Motojima, T. Takao, A. Ninomiya","doi":"10.1541/IEEJIAS.119.481","DOIUrl":"https://doi.org/10.1541/IEEJIAS.119.481","url":null,"abstract":"Superconducting conductors which are composed of many superconducting strands have a problem of current imbalance. This may cause the conductors to quench at a current level below its design value. This paper proposes the iron core methods to fix the current imbalance problem. The iron core method is the one in which two insulated strands are passed through an iron core with electric currents circulating in opposite directions. We investigated the current imbalance by using Ag sheathed Bi-2223 high temparature superconducting wire. We observed that the current imbalance was corrected by using ferrite iron core in liquid nitrogen. Finally, we discuss the size of iron core needed to solve the current imbalance problem.","PeriodicalId":7974,"journal":{"name":"Annual Report of National Institute for Fusion Science","volume":"46 1","pages":"75"},"PeriodicalIF":0.0,"publicationDate":"1999-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81063390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Evaluation of Low-Temperature Swelling in Austenitic Stainless Steels","authors":"Y. Katoh","doi":"10.1520/STP13903S","DOIUrl":"https://doi.org/10.1520/STP13903S","url":null,"abstract":"","PeriodicalId":7974,"journal":{"name":"Annual Report of National Institute for Fusion Science","volume":"64 1","pages":"103"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74537512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Mozjetchkov, T. Takanashi, Y. Oka, K. Tsumori, M. Osakabe, O. Kaneko, Y. Takeiri, T. Kuroda
Microwave plasma source for the negative hydrogen ion production was constructed and tested. The plasma source consists of two chambers: a plasma production chamber and a plasma confinement chamber. The production chamber is placed into the strong axial magnetic field and the microwaves (2.45 GHz, up to 5 kW) are introduced through the quartz window along the magnetic field lines. It is found that the suppression of the fast electron loss to the window holder is important to improve the efficiency of hydrogen plasma production. The plasma density increases with the magnetic field strength in the plasma production chamber. For the microwave power of 4 kW the uniform plasma of 3×1012 cm−3 for argon and 3×1011 cm−3 for hydrogen is obtained in the area of 20×20 cm. Electron temperature in the plasma grid region is around 2 eV. The optimum gas pressure is around 6 mTorr.
{"title":"Microwave Plasma Source for the Negative Hydrogen Ion Production","authors":"M. Mozjetchkov, T. Takanashi, Y. Oka, K. Tsumori, M. Osakabe, O. Kaneko, Y. Takeiri, T. Kuroda","doi":"10.1063/1.1148604","DOIUrl":"https://doi.org/10.1063/1.1148604","url":null,"abstract":"Microwave plasma source for the negative hydrogen ion production was constructed and tested. The plasma source consists of two chambers: a plasma production chamber and a plasma confinement chamber. The production chamber is placed into the strong axial magnetic field and the microwaves (2.45 GHz, up to 5 kW) are introduced through the quartz window along the magnetic field lines. It is found that the suppression of the fast electron loss to the window holder is important to improve the efficiency of hydrogen plasma production. The plasma density increases with the magnetic field strength in the plasma production chamber. For the microwave power of 4 kW the uniform plasma of 3×1012 cm−3 for argon and 3×1011 cm−3 for hydrogen is obtained in the area of 20×20 cm. Electron temperature in the plasma grid region is around 2 eV. The optimum gas pressure is around 6 mTorr.","PeriodicalId":7974,"journal":{"name":"Annual Report of National Institute for Fusion Science","volume":"11 1","pages":"123"},"PeriodicalIF":0.0,"publicationDate":"1998-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85109226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-06-01DOI: 10.1103/PHYSREVA.57.4387
I. Tolstikhina, O. Tolstikhin, H. Tawara
{"title":"Shake-off Mechanism of Two-Electron Transitions in Slow Ion-atom Collisions","authors":"I. Tolstikhina, O. Tolstikhin, H. Tawara","doi":"10.1103/PHYSREVA.57.4387","DOIUrl":"https://doi.org/10.1103/PHYSREVA.57.4387","url":null,"abstract":"","PeriodicalId":7974,"journal":{"name":"Annual Report of National Institute for Fusion Science","volume":"100 1 1","pages":"300"},"PeriodicalIF":0.0,"publicationDate":"1998-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78041566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1998-01-01DOI: 10.1007/978-1-4757-9047-4_24
S. Imagawa, H. Tamura, A. Nishimura, T. Satow, J. Yamamoto, O. Motojima, K. Nakanishi, O. Honma, M. Sudou, T. Kouda, T. Yamagiwa, K. Asano
{"title":"Completion of Helical Coils for LHD","authors":"S. Imagawa, H. Tamura, A. Nishimura, T. Satow, J. Yamamoto, O. Motojima, K. Nakanishi, O. Honma, M. Sudou, T. Kouda, T. Yamagiwa, K. Asano","doi":"10.1007/978-1-4757-9047-4_24","DOIUrl":"https://doi.org/10.1007/978-1-4757-9047-4_24","url":null,"abstract":"","PeriodicalId":7974,"journal":{"name":"Annual Report of National Institute for Fusion Science","volume":"1 1","pages":"213-220"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83655067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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