Optical lines of Xe⁹⁺ and Xe¹⁰⁺ ions measured at a low-energy electron beam ion trap.

This work reported the investigation of optical spectra of Rh-like Xe 9+ and Ru-like Xe 10+ ions at a low-energy electron beam ion trap. The line from 4 d 9 2 D 3/2 – 2 D 5/2 M1 transition of Xe 9+ ions was remeasured, the wavelength of which was determined to be 598.365(5) nm, and the uncertainty was significantly improved. In the region of 200–700 nm, four spectral lines emitted from Xe 10+ ions were directly observed for the first time. The relativistic many-body perturbation method was adopted for the investigation of fine structure in Xe 10+ ions. The theoretical and experimental results were in good agreement within 2%, and the four observed lines of Xe 10+ ions were identified.