Dirac R-matrix calculations of photoionization cross sections of Ni Ⅻ and atomic structure data of Ni

We performed R-matrix calculations for photoionization cross sections of the two ground state configuration 3s^23p^5（~2P_（3/2,1/2）~o） levels and 12 excited states of Ni Ⅻ using relativistic Dirac Atomic R-matrix Codes（DARC） across the photon energy range between the ionizations thresholds of the corresponding states and well above the thresholds of the last level of the Ni XIII target ion. Generally, a good agreement is obtained between our results and the earlier theoretical photoionization cross sections. Moreover, we have used two independent fully relativistic GRASP and FAC codes to calculate fine-structure energy levels, wavelengths, oscillator strengths, transitions rates among the lowest 48 levels belonging to the configuration（3s^23p^4, 3s3p^5, 3p^6, 3s^23p^33d） in Ni XIII. Additionally, radiative lifetimes of all the excited states of Ni XIII are presented. Our results of the atomic structure of Ni XIII show good agreement with other theoretical and experimental results available in the literature. A good agreement is found between our calculated lifetimes and the experimental ones.Our present results are useful for plasma diagnostic of fusion and astrophysical plasmas.

激光诱导荧光法测量钆原子光谱

为了有效地利用同位素研究钆原子的光谱特性。采用原子蒸气束激光诱导荧光法测量钆原子的第一激发态的同位素位移及超精细结构、原子跃迁自发辐射的分支比和原子蒸气束的多普勒宽度。通过对测量结果的分析和计算 ,分别给出钆原子 5条谱线的同位素位移和超精细结构、两个能级 (17795 .2 6 7cm- 1 ,172 2 7.96 9cm- 1 )的寿命 (2 37ns,94 7ns)和光吸收截面 (1.39× 10 - 1 3cm2和 8.77×10 - 1 4cm2 )。这些研究结果为进一步测量钆原子高激发态和电离态的光谱打下基础。