2016/11/04 by Momoe Mita, Hiroyuki A. Sakaue, Mita, Momoe +9
Engineering · Physics and Astronomy · #Atomic Physics (physics.atom-ph) #Atomic and Molecular Physics #FOS: Physical sciences #Magnetic confinement fusion research #Particle accelerators and beam dynamics #physics.atom-ph
paper · pdf · doi:10.48550/arxiv.1611.01261
arxiv created 2016/11/04 · openalex publication_date 2016/11/04 · arxiv updated 2016/11/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present direct observation of the M1 transition between the fine structure splitting in the 4f13 5s2 5p6 2F ground state of W VIII. The spectroscopic data of few-times ionized tungsten ions are important for the future ITER diagnostics, but there is a serious lack of data. The present study is part of an ongoing effort to solve this lack. Emission from the tungsten ions produced and trapped in a compact electron beam ion trap is observed with a Czerny-Turner visible spectrometer. Spectra in the EUV range are also observed at the same time to help the identification of the previously-unreported visible lines. The observed wavelength 574.47 pm 0.03 nm (air), which corresponds to the fine structure splitting of 17402.5 pm 0.9 cm-1, shows reasonable agreement with the previously reported value 17410 pm 5 cm-1 obtained indirectly through the analysis of EUV spectra [Ryabtsev et al., Atoms 3 (2015) 273].