Z-dependent three-level simultaneous-crossing of excited states in germanium-like highly charged atomic ions

Abstract

Simultaneous-crossing of three energy-levels has been found for the first time in the atomic number -dependent wavelength curves at = 66 of Ge-like highly charged atomic ions. Large Helical Device (LHD) and EBIT are used for obtaining the wavelength of EUV emissions from the transitions of 4 or 4 excited states into their ground state ([Ni]4242−)0. Multi-Configuration Dirac-Fock calculation has been carried out for analysis. Interactions between the three excited-state configurations ([Ni]424−4−)1, ([Ni]44−(42+)0)1, and ([Ni]44−(42+)2)1 lead to the three-dimensional rotation of atomic state-vectors in the configuration space on the way for to pass the crossing point. -evolution of the atomic states has been analyzed employing the quaternion algebra. The spectral anomalies near the level-crossing are simulated by the atomic state-vector rotation. The optically invisible states are thus become visible by sharing the intensities of optically allowed configuration ([Ni]424−4−)1.journal articl