Investigation of transitions between metastable levels of the first excited configuration of palladium-like tungsten

• Published in: Journal of physics. B, Atomic, molecular, and optical physics Vol. 47; no. 17; pp. 1 - 8
• Main Authors: Qiu, M L, Zhao, R F, Guo, X L, Zhao, Z Z, Li, W X, Du, S Y, Xiao, J, Yao, K, Chen, C Y, Hutton, R, Zou, Y
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 14.09.2014; Institute of Physics
• Subjects: Atomic and molecular physics; Atomic properties and interactions with photons; Atomic spectra; Charging; Conduction; EBIT; Exact sciences and technology; Excitation; Fine structure; Ionization; metastable; palladium-like; Physics; Plasmas; spectroscopy; Tungsten; Visible and ultraviolet spectra; Wavelengths; Fine structure; Plasma; Energy-level transitions; Lifetime; Tungsten ions; Metastable states; Ultraviolet spectra; High ionized ion; High temperature; Energy level population; MBPT theory
• ISSN: 0953-4075; 1361-6455
• DOI: 10.1088/0953-4075/47/17/175002

Spectroscopy in the wavelength region of 330 nm to 400 nm for highly charged tungsten was performed using the High Temperature Super Conducting Electron Beam Ion Trap (SH-HtscEBIT) at Fudan University. Three lines from palladium-like tungsten (W28+) were identified as transitions between metastable levels in the first excited configuration ([Kr]4d94f). A second-order relativistic many-body perturbation theory approach and a simple collisional radiative model were used to theoretically study the fine structure levels of the 4d94f configuration. The calculated results show qualitative agreement with experiment. We conclude that some levels in the 4d94f excited configuration have extremely long lifetimes and may exhibit extraordinarily high populations, possibly leading to indirect ionization in, for example, fusion plasmas.