Plasma and Fusion Research

Volume 20, 2402011 (2025)

Regular Articles


Observation and Line Analysis of Tungsten, Molybdenum and Copper Spectra at 20-150Å Emitted from Experimental Advanced Superconducting Tokamak (EAST) Plasma
Ling ZHANG1), Wenmin ZHANG2,1), Yunxin CHENG1), Shigeru MORITA3,1), Ailan HU1), Chengxi ZHOU1), Darío MITNIK4), Jihui CHEN1) and Haiqing LIU1)
1)
Institute of plasma physics, Chinese Academy of Sciences, Hefei 230031, China
2)
University of Science and Technology of China, Hefei 230026, China
3)
National Institute for Fusion Science, Toki, Gifu 509-5292, Japan
4)
Instituto de Astronomía y Física del Espacio, Buenos Aires 1428, Argentina
(Received 30 July 2024 / Accepted 16 October 2024 / Published 22 January 2025)

Abstract

Complex spectra of tungsten (W) and molybdenum (Mo) unresolved transition arrays (W-UTA and Mo-UTA) are frequently observed with isolated W, Mo and copper (Cu) lines at 20-150Å wavelength range in EAST plasmas with limiter configuration. The high-Z impurity ions of W, Mo and Cu enter the plasma through an unavoidable plasma-wall interaction at inboard Mo first wall and outboard W/Cu limiter. The spectra were observed with a fast-time-response extreme ultraviolet (EUV) spectrometer and line identification was carefully performed referring our previous works. As a result, W-UTA at 46-64Å and Mo-UTA at 68-96Å are found to be composed of W27+-W45+ and Mo16+-Mo30+ ions, respectively. The Cu spectra from Cu10+-Cu13+ ions are also found in wavelength range of 135-150 Å. In the analysis radial profiles of the impurity spectra are taken into account in determining the charge state in addition to the time behavior.


Keywords

EAST tokamak, EUV spectra, tungsten first wall

DOI: 10.1585/pfr.20.2402011


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