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arXiv · 2405.00893

Stepwise ionization of Mo$^{14+}$ ions in EBIT: The importance of the metastable level

Cunqiang Wu·Xiaobin Ding·Qi Guo·Ke Yao·Jialin Liu·Yunqing Fu·Chenzhong Dong
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Abstract

The visible spectrum of Mo$^{15+}$ ions was measured using a high-temperature superconducting electron-beam ion trap at the Shanghai EBIT Laboratory, with an electron beam energy $E_{e}$=400 eV, significantly lower than the ionization potential (IP=544.0 eV) of Mo$^{14+}$ ions in the ground state. To expound on the experiment, the energy level structure, radiative transition properties, electron-impact excitation, and electron-impact ionization cross section for both the ground state and low-lying excited state of the Mo$^{14+}$ ions were calculated using Dirac-Fock-Slater method with a local central potential and distorted wave approximation. The results demonstrated reasonable agreement with both available experimental and theoretical data. Through an analysis of the related atomic processes of Mo$^{14+}$ ion, a scenario involving the stepwise ionization of the metastable state 3p$^{6}$3d$^{9}$4s was proposed to explain the presence of the Mo$^{15+}$ ions with a lower energy of the incident electron. Finally, the significance of the metastable levels in ionizing Mo$^{14+}$ ions is highlighted.

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Cunqiang Wu, Xiaobin Ding, Qi Guo, Ke Yao, Jialin Liu, Yunqing Fu, Chenzhong Dong. 2024-05-01. Stepwise ionization of Mo$^{14+}$ ions in EBIT: The importance of the metastable level. https://doi.org/10.1103/physreva.111.042818

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