Interpretation of spectral emission in the 20 nm region from tungsten ions observed in fusion device plasmas
Interpretation of spectral emission in the 20 nm region from tungsten ions observed in fusion device plasmas
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DOI：
10.1088/0953-4075/44/17/175004
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发表时间：
2011-08
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通讯作者：
C. Suzuki;C. S. Harte;D. Kilbane;Takako Katō;H. Sakaue;Izumi Murakami;Daiji Kato;K. Sato;Naoki Tamura;Shigeru Sudo;Motoshi Goto;R. D’Arcy;E. Sokell;Gerry O’Sullivan
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文献类型：
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作者：
C. Suzuki;C. S. Harte;D. Kilbane;Takako Katō;H. Sakaue;Izumi Murakami;Daiji Kato;K. Sato;Naoki Tamura;Shigeru Sudo;Motoshi Goto;R. D’Arcy;E. Sokell;Gerry O’Sullivan
我们已经测量了极紫外光谱钨离子在20 nm区域的等离子体中产生的大型螺旋装置在国家聚变科学研究所。用掠入射光谱仪测量了钨颗粒注入氢等离子体后的光谱。在温度低于1.0 keV的等离子体中，观察到了20 nm左右的由未分辨跃迁阵列（UTA）引起的准连续谱特征。这种结构被合理地认为与在另一个托克马克装置或低温条件下激光产生的等离子体中观察到的结构相同。对具有开放的5 p、5s和4f亚壳层的钨离子（W ~（7+）-W ~（27+））进行了原子结构计算，解释了在20 nm附近观察到的特征。计算了这些跃迁的波长和强度，并将UTA的平均波长和范围与观测值进行了比较，结果表明，UTA的发射主要来自于低于W27 +的n = 5-5跃迁。
We have measured extreme ultraviolet spectra from tungsten ions in the 20 nm region in plasmas produced in the Large Helical Device at the National Institute for Fusion Science. The spectra following injection of a tungsten pellet into a hydrogen plasma were monitored by a grazing incidence spectrometer. A quasicontinuum spectral feature arising from an unresolved transition array (UTA) was observed around 20 nm in plasmas with temperatures below 1.0 keV. This structure is reasonably considered to be the same as observed in another tokamak device or laser-produced plasmas under low-temperature conditions. Atomic structure calculations have been performed for tungsten ions with open 5p, 5s and 4f subshells (W7 +–W27 +) to interpret the observed feature around 20 nm. Wavelengths and strengths for these transitions were calculated, and mean wavelengths and extent of the UTAs were compared with the observations, which suggests that the emission largely arises from n = 5–5 transitions in stages lower than W27 +.