The Nd:YAG laser with a wavelength of 1.064 μ m was used to generate plasmas on a high-purity solid ytterbium ( 70 Yb) target in a vacuum chamber. The soft x-ray time- and space-integration spectra from the Yb plasmas were measured in the wavelength range of 1.0–8.5 nm under different power densities. The atomic spectral data of the unresolved transition arrays from highly charged Yb ions were calculated based on Cowan’s suite of codes, including configuration interaction. The calculated Gaussian envelope of the emission determined by the weighted spontaneous transition rates was compared with the experimental spectra, and a good agreement between them was obtained. The spatial-temporal evolutions of the plasmas under the experimental conditions are simulated based on the collisional-radiative model, enabling the understanding of the mechanism of the plasma conditions for optimal water window waveband emission output.

中文翻译：

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脉冲1μm Nd：YAG激光诱导的plasma等离子体的x射线软光谱研究

波长为1.064μm的Nd：YAG激光器用于在真空室内的高纯度固态（（70 Yb）靶上产生等离子体。在不同功率密度下，在1.0–8.5 nm的波长范围内测量了Yb等离子体的软X射线时间和空间积分光谱。来自高电荷Yb离子的未解析跃迁阵列的原子光谱数据是基于Cowan的一组编码（包括配置相互作用）计算得出的。将由加权的自发跃迁速率确定的发射的高斯包络与实验光谱进行比较，并在它们之间获得了良好的一致性。基于碰撞辐射模型，模拟了实验条件下等离子体的时空演化，