Correlation of VUV intensity and basic plasma parameters
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摘要: 东方超环(EAST)上高速真空紫外(VUV)成像系统是一套选择性测量中心波长为13.5 nm的等离子体线辐射的光学成像系统。此系统具有高时空分辨能力，主要用于边界(包括台基区)等离子体行为研究。该系统已经投入EAST等离子体物理实验并获得了大量的实验数据。基于这些数据，分析了VUV诊断系统的信号强度与等离子体宏观参数之间的相关性，着重研究了EAST上中性束注入(NBI)加热功率、杂质(碳和锂)水平、电子密度等因素对VUV信号强度的影响。结果与预期基本一致：随着NBI功率的增加，VUV信号强度随之增强；VUV信号强度与电子密度、杂质水平呈现线性关系。此外，本文还评估了由于NBI注入引起的电荷交换复合产生的C5+离子对VUV信号的贡献，结果表明这部分贡献可以忽略不计。Abstract: The high-speed vacuum ultraviolet (VUV) imaging system on the Experimental Advanced Superconducting Tokamak (EAST) is an optic system with both high temporal and spatial resolutions, and it can selectively measure VUV photons with a wavelength of 13.5 nm, which mainly come from the impurities line emission from the plasma. It is being developed for edge plasma studies and has been operated routinely during the 2016 EAST experiment campaign. In this work, effect on the VUV intensity of basic plasma parameters (i.e. plasma density, light impurities and neutral beam injection(NBI) heating power) is analyzed. The VUV intensity increases with the increases of the NBI heating power, the electron density and impurity (carbon and lithium) concentration, which is qualitatively consistent with the prediction. In addition, the contribution to the VUV intensity of the C5+ ions generated though the charge exchange recombination process during the neutral beam injection has been estimated, and it indicates that this effect can be neglected.
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Key words:
- VUV imaging system /
- neutral beam injection(NBI) /
- plasma /
- impurity concentration
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图 2 CⅥ线辐射的光子发射率与电子温度的关系
Figure 2. Temperature dependence of the photon emissivity of CⅥ(p→ q=4 → 2 transition)
图 3 NBI (A&F窗口)和VUV(D窗口)成像诊断系统相对位置示意图
Figure 3. Diagram of the locations of neutral beam injection(NBI) system (A&F port) and VUV camera system (D port)on EAST
图 5 不同NBI加热功率下的电子密度和电子温度分布
Figure 5. Typical electron density and temperature profiles with different NBI heating power
图 6 不同NBI加热功率下的C5+离子电离平均自由程
Figure 6. Ionization mean free path of C5+ as a function of normalized radius of plasma with different NBI heating power
图 7 电子密度对VUV信号强度的影响
Figure 7. Effect of the line-averaged electron density on VUV intensity
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[1] Gao Xiang. Diagnostics for first plasma study on EAST tokamak[J]. Physics Letters A, 2008, 372(13): 2286-2290. doi: 10.1016/j.physleta.2007.11.014 [2] Tfr E. Line radiation in the visible and in the ultraviolet in TFR tokamak plasmas[J]. Nuclear Fusion, 1975, 15(6): 1053-1066. doi: 10.1088/0029-5515/15/6/011 [3] Liu Haiqing, Jie Yinxian, Ding W X, et al. Design of far-infrared polarimeter/interferometer system for EAST Tokamak[J]. Journal of Instrumentation, 2013, 8(11): C11002. doi: 10.1088/1748-0221/8/11/C11002 [4] Zhang Shoubiao, Gao Xiang, Ling Bili, et al. Density profile and fluctuation measurements by microwave reflectometry on EAST[J]. Plasma Science and Technology, 2014, 16(4): 311-315. doi: 10.1088/1009-0630/16/4/02 [5] Zang Qing, Zhao Junyu, Yang Li, et al. Development of a Thomson scattering diagnostic system on EAST[J]. Plasma Science and Technology, 2010, 12(2): 144-148. [6] Li Yingying, Fu J, Lyu B, et al. Development of the charge exchange recombination spectroscopy and the beam emission spectroscopy on the EAST tokamak[J]. Review of Scientific Instruments, 2014, 85(11): 11E428. [7] Zhang Ling, Morita S, Xu Zong, et al. A fast-time-response extreme ultraviolet spectrometer for measurement of impurity line emissions in the Experimental Advanced Superconducting Tokamak[J]. Review of Scientific Instruments, 2015, 86(12): 123509. [8] 张凌, 吴振伟, 高伟, 等. EAST托卡马克等离子体可见光谱辐射研究[C]//中国核学会年会, 2009: 20-23.Zhang Ling, Wu Zhenwei, Gao Wei, et al. Visible spectral radiation of the plasma in EAST//Annual Academic Meeting of China Nuclear Society, 2009: 20-23 [9] Jia Manni, Yang Qingquan, Zhong Fangchuan, et al. A tangentially visible fast imaging system on EAST[J]. Plasma Science and Technology, 2015, 17(12): 991-996. doi: 10.1088/1009-0630/17/12/02 [10] Ming Tingfeng, Ohdachi S, Suzuki Y, et al. Estimate of the deposition profile of carbon pellets using a high-speed VUV imaging system in the LHD[J]. Plasma Science & Technology, 2013, 15(12): 1178-1183. [11] Zurro B, García-Castañer B. A VUV filter spectrometer with spatial resolution and its plasma diagnostic capabilities[J]. Review of Scientific Instruments, 1994, 65(8): 2580-2584. doi: 10.1063/1.1144654 [12] Zhou Fan, Ming Tingfeng, Wang Yumin, et al. Development of a high-speed vacuum ultraviolet (VUV) imaging system for the Experimental Advanced Superconducting Tokamak[J]. Review of Scientific Instruments, 2017, 88(7): 073505. doi: 10.1063/1.4991856 [13] Ming Tingfeng. Development of high-speed vacuum ultraviolet imaging camera system for high-temperature plasma diagnostics[D]. Tokyo: Department of Fusion Science School of Physical Sciences, 2012: 75-77. [14] http://www.adas.ac.uk/[DB/OL]. [15] 王骥. EAST中性束注入加热与电流驱动模拟研究[D]. 合肥: 中国科学技术大学, 2012: 58-65.Wang Ji. The study on simulation of heating and beam-driven current for neutral beam injection on EAST. Hefei: University of Science and Technology of China, 2012: 58-65 [16] Groth M, Andrew P, Fundamenski W, et al. Helium and neon enrichment studies in the JET Mark ⅡAP and Mark ⅡGB divertors[J]. Nuclear Fusion, 2002, 42(5): 591-600. doi: 10.1088/0029-5515/42/5/311 -
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