Algorithm improvement for the surface morphology diagnostics based on the Gram-Schmidt orthonormalization and the least square ellipse fitting under the EAST-like vibrational environments
To realize in situ surface morphology diagnosis of Plasma-Facing Materials (PFMs) in the Experimental Advanced Superconducting Tokamak (EAST), a diagnostic system which is called DUT-SIEP (Speckle Interferometry Experiment Platform in Dalian University of Technology) is in development. Mimicking the...
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Elsevier
2023-06-01
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| Series: | Nuclear Materials and Energy |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2352179123000364 |
| _version_ | 1797801054879875072 |
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| author | Yuanbo Li Xiaoqian Cui Chunlei Feng Hongbei Wang Hongbin Ding |
| author_facet | Yuanbo Li Xiaoqian Cui Chunlei Feng Hongbei Wang Hongbin Ding |
| author_sort | Yuanbo Li |
| collection | DOAJ |
| description | To realize in situ surface morphology diagnosis of Plasma-Facing Materials (PFMs) in the Experimental Advanced Superconducting Tokamak (EAST), a diagnostic system which is called DUT-SIEP (Speckle Interferometry Experiment Platform in Dalian University of Technology) is in development. Mimicking the actual vibrational conditions in EAST, Dual-wavelength Phase-Shifting Interferometry (DPSI) should be sensitive to vibrational environment and would reduce accuracy in the morphology measurements. Therefore, an approach combining the Gram–Schmidt orthonormalization and the Least-Square Ellipse Fitting (GS-LSEF) was proposed to replace the conventional phase extraction process to improve the measurement accuracy in the EAST-like vibration conditions. The new approach only requires two interferograms at each wavelength while the conventional method needs three at least for each wavelength. This significantly reduces the phase errors in the acquisition processes. The Gram–Schmidt orthonormalization is performed to correct the phase shift errors and determine the elliptic coefficients. In the Least-Square Ellipse Fitting, the elliptic coefficients are used to compensate the phase errors from the disturbed background intensity. The approach can significantly improve the measurement efficiency and avoid the infinite loops caused by the numeric divergent. The method was verified by laser ablation on tungsten (W) material for simulating erosion-processes in EAST. Results show that the proposed approach has significantly improved in accuracy by approximately twofold comparing with those by the convenient Four-step phase-shifting approaches due to reducing the noise superposition problems in the EAST-like vibrational conditions. |
| first_indexed | 2024-03-13T04:44:35Z |
| format | Article |
| id | doaj.art-8be352e570f34c4795ff1e30664269df |
| institution | Directory Open Access Journal |
| issn | 2352-1791 |
| language | English |
| last_indexed | 2024-03-13T04:44:35Z |
| publishDate | 2023-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Nuclear Materials and Energy |
| spelling | doaj.art-8be352e570f34c4795ff1e30664269df2023-06-19T04:28:24ZengElsevierNuclear Materials and Energy2352-17912023-06-0135101397Algorithm improvement for the surface morphology diagnostics based on the Gram-Schmidt orthonormalization and the least square ellipse fitting under the EAST-like vibrational environmentsYuanbo Li0Xiaoqian Cui1Chunlei Feng2Hongbei Wang3Hongbin Ding4School of Physics and Optical Electronic Technology, Dalian University of Technology, Dalian 116024, PR ChinaSchool of Physics and Optical Electronic Technology, Dalian University of Technology, Dalian 116024, PR China; Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, PR ChinaSchool of Physics and Optical Electronic Technology, Dalian University of Technology, Dalian 116024, PR ChinaSchool of Physics and Optical Electronic Technology, Dalian University of Technology, Dalian 116024, PR China; Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031, PR China; Institute of Energy, Hefei Comprehensive National Science Center, Anhui, Hefei, 230031, PR China; Corresponding authors at: School of Physics and Optical Electronic Technology, Dalian University of Technology, Dalian 116024, PR China.School of Physics and Optical Electronic Technology, Dalian University of Technology, Dalian 116024, PR China; Corresponding authors at: School of Physics and Optical Electronic Technology, Dalian University of Technology, Dalian 116024, PR China.To realize in situ surface morphology diagnosis of Plasma-Facing Materials (PFMs) in the Experimental Advanced Superconducting Tokamak (EAST), a diagnostic system which is called DUT-SIEP (Speckle Interferometry Experiment Platform in Dalian University of Technology) is in development. Mimicking the actual vibrational conditions in EAST, Dual-wavelength Phase-Shifting Interferometry (DPSI) should be sensitive to vibrational environment and would reduce accuracy in the morphology measurements. Therefore, an approach combining the Gram–Schmidt orthonormalization and the Least-Square Ellipse Fitting (GS-LSEF) was proposed to replace the conventional phase extraction process to improve the measurement accuracy in the EAST-like vibration conditions. The new approach only requires two interferograms at each wavelength while the conventional method needs three at least for each wavelength. This significantly reduces the phase errors in the acquisition processes. The Gram–Schmidt orthonormalization is performed to correct the phase shift errors and determine the elliptic coefficients. In the Least-Square Ellipse Fitting, the elliptic coefficients are used to compensate the phase errors from the disturbed background intensity. The approach can significantly improve the measurement efficiency and avoid the infinite loops caused by the numeric divergent. The method was verified by laser ablation on tungsten (W) material for simulating erosion-processes in EAST. Results show that the proposed approach has significantly improved in accuracy by approximately twofold comparing with those by the convenient Four-step phase-shifting approaches due to reducing the noise superposition problems in the EAST-like vibrational conditions.http://www.sciencedirect.com/science/article/pii/S2352179123000364TokamakSurface morphology diagnosisEAST-like vibrationGram-Schmidt orthonormalizationLeast-Square Ellipse Fitting |
| spellingShingle | Yuanbo Li Xiaoqian Cui Chunlei Feng Hongbei Wang Hongbin Ding Algorithm improvement for the surface morphology diagnostics based on the Gram-Schmidt orthonormalization and the least square ellipse fitting under the EAST-like vibrational environments Nuclear Materials and Energy Tokamak Surface morphology diagnosis EAST-like vibration Gram-Schmidt orthonormalization Least-Square Ellipse Fitting |
| title | Algorithm improvement for the surface morphology diagnostics based on the Gram-Schmidt orthonormalization and the least square ellipse fitting under the EAST-like vibrational environments |
| title_full | Algorithm improvement for the surface morphology diagnostics based on the Gram-Schmidt orthonormalization and the least square ellipse fitting under the EAST-like vibrational environments |
| title_fullStr | Algorithm improvement for the surface morphology diagnostics based on the Gram-Schmidt orthonormalization and the least square ellipse fitting under the EAST-like vibrational environments |
| title_full_unstemmed | Algorithm improvement for the surface morphology diagnostics based on the Gram-Schmidt orthonormalization and the least square ellipse fitting under the EAST-like vibrational environments |
| title_short | Algorithm improvement for the surface morphology diagnostics based on the Gram-Schmidt orthonormalization and the least square ellipse fitting under the EAST-like vibrational environments |
| title_sort | algorithm improvement for the surface morphology diagnostics based on the gram schmidt orthonormalization and the least square ellipse fitting under the east like vibrational environments |
| topic | Tokamak Surface morphology diagnosis EAST-like vibration Gram-Schmidt orthonormalization Least-Square Ellipse Fitting |
| url | http://www.sciencedirect.com/science/article/pii/S2352179123000364 |
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