The rate coefficients for dielectronic recombination (DR) of lithium-like ⁴⁰Ca¹⁷⁺ ions with ∆n = 0 core excitations are derived from electron–ion recombination spectra measured with merged-beams method at the heavy-ion storage ring CSRm. The experimental DR spectrum, in the electron–ion collision energy range of 0 to 42 eV in the center-of-mass frame, comprises of all DR resonance peaks belong to the 2s ² S _1/2 → 2p ² P _{1/2, 3/2} core excitations. The resonant energies and strengths for the resolved resonances in 2pjnl series are determined by fitting of the measured DR peaks. The further interpretation of the measured DR rate coefficients has been performed by calculating the DR rate coefficients with relativistic configuration-interaction method implemented in flexible atomic code (FAC) and compared with the experimental results. The experimental results and FAC calculations are found to be in a good agreement within the experimental uncertainties. Moreover, temperature dependent plasma rate coefficients were constructed from 4 × 10³ to 1 × 10⁷ K energy region by convoluting experimental and theoretical DR rate coefficients with the Maxwellian energy distribution function and then compared with previously available data. The plasma DR rate coefficient is found to be significantly underestimated by the early theoretical data calculated by Jacobs et al, and Mazotta et al in the low temperature. In contrast, a very good agreement has been found between the theoretical DR data of Gu and Colgan et al and the presently measured results at the low temperature region. Therefore, the results in this work composed of a bench-mark data set for plasma modeling at the photoionized temperature range. We have also provided a fit to our measured and theoretical plasma rate coefficients for low temperature plasma modeling.

中文翻译：

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类锂 40Ca17+ 的实验双电子复合率系数

^{具有 ∆ 的类锂40} Ca ¹⁷⁺离子的双电子复合 (DR) 速率系数n= 0 核心激发源自在重离子存储环 CSRm 处用合并束法测量的电子-离子复合光谱。实验 DR 光谱，在质心框架中 0 到 42 eV 的电子-离子碰撞能量范围内，包括属于 2 的所有 DR 共振峰秒 ^2个 小号 _1/2 → 2p ^2个 P _1/2、3/2核心激励。2 中解析共振的共振能量和强度pjnl系列是通过拟合测得的 DR 峰来确定的。通过使用在灵活原子码（FAC）中实现的相对论配置 - 相互作用方法计算DR速率系数并与实验结果进行比较，对测量的DR速率系数进行了进一步的解释。发现实验结果和 FAC 计算在实验不确定性范围内非常吻合。此外，温度相关等离子体速率系数的构造范围为 4 × 10 ³至 1 × 10 ⁷ K 能量区域通过卷积实验和理论 DR 速率系数与麦克斯韦能量分布函数，然后与以前可用的数据进行比较。发现血浆DR率系数被Jacobs计算的早期理论数据明显低估等人, 和马佐塔等人在低温下。相比之下，在 Gu 和 Colgan 的理论 DR 数据之间发现了非常好的一致性等人以及目前在低温区的测量结果。因此，这项工作的结果由一个基准数据集组成，用于在光离子化温度范围内进行等离子体建模。我们还为低温等离子体建模提供了对我们的测量和理论等离子体速率系数的拟合。