Evaluation of tungsten influx rate using line emissions from W5+ ions in EAST tokamak
The S/XB ratios (ionization events per emitted photon) allow one to relate spectroscopic emissivity measurements to the impurity influx from a localized source. In this work, we determine the tungsten influx by examining two dominant extreme ultraviolet line emissions at 382.13 Å and 394.07 Å, corre...
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IOP Publishing
2025-01-01
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| Online Access: | https://doi.org/10.1088/1741-4326/adb598 |
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| author | Fengling Zhang Darío Mitnik Ling Zhang Runjia Bao Wenmin Zhang Shigeru Morita Yunxin Cheng Ailan Hu Chengxi Zhou Jihui Chen Xiaobin Ding Yinxian Jie Haiqing Liu |
| author_facet | Fengling Zhang Darío Mitnik Ling Zhang Runjia Bao Wenmin Zhang Shigeru Morita Yunxin Cheng Ailan Hu Chengxi Zhou Jihui Chen Xiaobin Ding Yinxian Jie Haiqing Liu |
| author_sort | Fengling Zhang |
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| description | The S/XB ratios (ionization events per emitted photon) allow one to relate spectroscopic emissivity measurements to the impurity influx from a localized source. In this work, we determine the tungsten influx by examining two dominant extreme ultraviolet line emissions at 382.13 Å and 394.07 Å, corresponding to the $4f^{14}5f \rightarrow 4f^{14}5d$ radiative transitions of the W ^5+ ion. The ground configuration of W ^5+ consists of the ground level and a metastable level, with the latter having a higher population than the ground state. Therefore, a simple approach assuming that the transitions are independent, i.e. only populated by a unique level source, requires correction. To address this, we have developed a fully collisional-radiative modeling in which 430 levels contribute to the ionization. We have utilized three advanced computational codes – hullac (Hebrew University—Lawrence Livermore Atomic Code, AS (AutoStructure), and FAC (Flexible Atomic Code) – for the atomic structure calculations. These codes provide the necessary information such as wavelengths, collisional and radiative transition rate coefficients. The fac code was also used to calculate the direct electron-impact ionization under the distorted-wave approximation. We also included contributions to total ionization from excitation-autoionization processes up to n = 15 manifolds from the distorted-wave calculations. Subsequently, we used these results to ascertain the tungsten impurity influx in a dedicated discharge of the EAST tokamak, which operates with full tungsten divertors. In our findings, we observed that for the density range relevant to the edge region of a tokamak plasma, the S/XB ratios are almost independent of electron density but exhibit significant variation with electron temperature. |
| format | Article |
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| issn | 0029-5515 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
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| series | Nuclear Fusion |
| spelling | doaj-art-aa60de1b02024c3ca5852f8a4111b1942025-08-20T02:55:03ZengIOP PublishingNuclear Fusion0029-55152025-01-0165303603710.1088/1741-4326/adb598Evaluation of tungsten influx rate using line emissions from W5+ ions in EAST tokamakFengling Zhang0https://orcid.org/0009-0008-0873-0071Darío Mitnik1https://orcid.org/0000-0003-0193-0958Ling Zhang2https://orcid.org/0000-0001-7880-9588Runjia Bao3Wenmin Zhang4https://orcid.org/0009-0000-9980-6765Shigeru Morita5https://orcid.org/0000-0003-4139-7721Yunxin Cheng6https://orcid.org/0000-0002-9195-2757Ailan Hu7Chengxi Zhou8Jihui Chen9Xiaobin Ding10https://orcid.org/0000-0003-0004-3206Yinxian Jie11Haiqing Liu12https://orcid.org/0000-0001-6892-358XInstitute of Plasma Physics , Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; University of Science and Technology of China , Hefei 230026, ChinaInstitute of Plasma Physics , Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; Instituto de Astronomía y Física del Espacio (CONICET-Universidad de Buenos Aires) , Buenos Aires 1428, ArgentinaInstitute of Plasma Physics , Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, ChinaInstitute of Plasma Physics , Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; University of Science and Technology of China , Hefei 230026, ChinaInstitute of Plasma Physics , Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; University of Science and Technology of China , Hefei 230026, ChinaInstitute of Plasma Physics , Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China; National Institute for Fusion Science , Toki 509-5292, Gifu, JapanInstitute of Plasma Physics , Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, ChinaInstitute of Plasma Physics , Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, ChinaInstitute of Plasma Physics , Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, ChinaInstitute of Plasma Physics , Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, ChinaKey laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province , College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070, ChinaInstitute of Plasma Physics , Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, ChinaInstitute of Plasma Physics , Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, ChinaThe S/XB ratios (ionization events per emitted photon) allow one to relate spectroscopic emissivity measurements to the impurity influx from a localized source. In this work, we determine the tungsten influx by examining two dominant extreme ultraviolet line emissions at 382.13 Å and 394.07 Å, corresponding to the $4f^{14}5f \rightarrow 4f^{14}5d$ radiative transitions of the W ^5+ ion. The ground configuration of W ^5+ consists of the ground level and a metastable level, with the latter having a higher population than the ground state. Therefore, a simple approach assuming that the transitions are independent, i.e. only populated by a unique level source, requires correction. To address this, we have developed a fully collisional-radiative modeling in which 430 levels contribute to the ionization. We have utilized three advanced computational codes – hullac (Hebrew University—Lawrence Livermore Atomic Code, AS (AutoStructure), and FAC (Flexible Atomic Code) – for the atomic structure calculations. These codes provide the necessary information such as wavelengths, collisional and radiative transition rate coefficients. The fac code was also used to calculate the direct electron-impact ionization under the distorted-wave approximation. We also included contributions to total ionization from excitation-autoionization processes up to n = 15 manifolds from the distorted-wave calculations. Subsequently, we used these results to ascertain the tungsten impurity influx in a dedicated discharge of the EAST tokamak, which operates with full tungsten divertors. In our findings, we observed that for the density range relevant to the edge region of a tokamak plasma, the S/XB ratios are almost independent of electron density but exhibit significant variation with electron temperature.https://doi.org/10.1088/1741-4326/adb598impurity influx in tokamakS/XB valuesEUV spectroscopytungsten spectroscopy |
| spellingShingle | Fengling Zhang Darío Mitnik Ling Zhang Runjia Bao Wenmin Zhang Shigeru Morita Yunxin Cheng Ailan Hu Chengxi Zhou Jihui Chen Xiaobin Ding Yinxian Jie Haiqing Liu Evaluation of tungsten influx rate using line emissions from W5+ ions in EAST tokamak Nuclear Fusion impurity influx in tokamak S/XB values EUV spectroscopy tungsten spectroscopy |
| title | Evaluation of tungsten influx rate using line emissions from W5+ ions in EAST tokamak |
| title_full | Evaluation of tungsten influx rate using line emissions from W5+ ions in EAST tokamak |
| title_fullStr | Evaluation of tungsten influx rate using line emissions from W5+ ions in EAST tokamak |
| title_full_unstemmed | Evaluation of tungsten influx rate using line emissions from W5+ ions in EAST tokamak |
| title_short | Evaluation of tungsten influx rate using line emissions from W5+ ions in EAST tokamak |
| title_sort | evaluation of tungsten influx rate using line emissions from w5 ions in east tokamak |
| topic | impurity influx in tokamak S/XB values EUV spectroscopy tungsten spectroscopy |
| url | https://doi.org/10.1088/1741-4326/adb598 |
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