Spectral line identification for highly charged heavy ions in soft X-ray and EUV regions based on Z-dependence measurements

Abstract

ORCID　0000-0001-6536-9034This study focuses on new identifications of discrete spectral lines of heavy ions with one or two outermost 4s/4p subshell electrons in soft X-ray and extreme ultraviolet regions. The study is basically based on the spectroscopic data systematically taken in the last decades in high-temperature plasmas produced in the Large Helical Device using multiple grazing incidence spectrometers. In addition, we have newly taken spectroscopic data using the Tokyo electron beam ion trap (EBIT) for some of the missing elements in the past EBIT experiments. Consequently, we could identify a number of discrete lines experimentally for the first time in this study based on the detailed atomic number (Z)-dependences of the wavelengths of major resonance lines. Some transitions of Ga- and Ge-like ions show irregular Z-dependences in which the transition wavelength suddenly shifts to another curve at around a specific Z due to the effect of strong configuration interaction.journal articl