Evidence for strong configuration mixing in n=3 excited levels in neonlike ions -: art. no. 052510

Wavelengths have been measured for x-ray transitions From the excited states with strong configuration mixing between (2p(1/2)(-1) 3s)(J=1) and (2p(3/2)(-1)3d(5/2))(J=1) to the ground states in neonlike I43+, Cs45+, and Ba46+ The measurements were made with a flat crystal spectrometer on the Tokyo electron beam ion trap. The experimental wavelengths are compared to theoretical values calculated with the multiconfigurational Dirac-Fock method and other existing theoretical results. Using the present results, the degree of mixing in the wave functions between the two excited electronic configurations is investigated. The present investigation gives a clear demonstration for strong configuration mixing in highly charged ions through observation of an avoided crossing.