Ionization of one-electron ions and capture by bare and one-electron ions of C, N, O, and F on He
Ionization of one-electron ions and capture by bare and one-electron ions of C, N, O, and F on He
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He 上单电子离子的电离以及 C、N、O 和 F 的裸离子和单电子离子的捕获
DOI：
10.1103/physreva.24.1237
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发表时间：
1981
影响因子：
2.9
通讯作者：
P. Richard
中科院分区：
文献类型：
--
作者：
T. R. Dillingham;J. Macdonald;P. Richard
实验测量的单电子转移截面的裸核和单电子离子的C，N，O和F与He气体靶碰撞后的能量范围从\ensuremath{\sim}0.5-2.5 MeV / amu。良好的协议之间的$K-壳层电离截面（电子损失单电子离子）和理论平面波玻恩近似计算不包括库仑偏转和结合能修正。捕获截面（电子增益）和以前测得的总射弹的X射线截面之间的比较。将X射线截面与总捕获截面的比率与通过Brinkman-Kramers（BK）计算发现的相同比率进行比较。比较结果表明，在X射线截面理论分析中，采用单一的归一化常数对各态的俘获是不够的。特别是，结果表明，BK计算低估了捕获的电子的$1s \mathrm{和} 2s$状态相比，更高的，X射线发射状态。总俘获截面也给出了$\frac{E}{M}$（MeV / amu）的函数。对于给定的速度，捕获仅取决于入射离子的电荷状态。此外，电荷变化过程$q\ensuremath{\rightarrow}q\ensuremath{-}1（q= 8，7，\mathrm {and} 6）$的平均比率为1：0.68：0.44的类似速度依赖性对应于总截面的${q}^{3}$依赖性。
Experimentally measured single-electron-transfer cross sections are presented for bare nuclei and one-electron ions of C, N, O, and F following collisions with a He-gas target in the energy range from \ensuremath{\sim}0.5-2.5 MeV / amu. Excellent agreement is found between the $K$-shell ionization cross sections (electron loss by one-electron ions) and a theoretical plane-wave-Born-approximation calculation without inclusion of Coulomb-deflection and binding-energy corrections. Comparisons are also made between the capture cross sections (electron gain) and previously measured total projectile x-ray cross sections. The ratio of the x-ray cross section to the total capture cross section is compared to the same ratio found through a Brinkman-Kramers (BK) calculation. The results of the comparison show that the single normalization constant for the capture to each state, which was used in the theoretical analysis of the x-ray cross section, is inadequate. In particular, the results show that the BK calculation underestimates the capture of the electron to the $1s \mathrm{and} 2s$ states as compared to the higher, x-ray-emitting states. The total capture cross sections are also given as a function of $\frac{E}{M}$ (MeV / amu). For a given velocity the capture is dependent only upon the charge state of the incident ion. Also, the similar velocity dependence with average ratios of 1:0.68:0.44 for the charge-changing processes $q\ensuremath{\rightarrow}q\ensuremath{-}1(q=8,7,\mathrm{and} 6)$ correspond to a ${q}^{3}$ dependence for the total cross section.