Inner-shell excitation of argon dielectronic satellite spectral lines in imploded microballoon plasmas

The dielectronic satellite transitions, originating on the 2s2p 3 P and 2p 2 3 P doubly excited levels of helium-like Ar XVII, are identified in the spectrum from the laser-imploded core plasma of an argon filled glass microballoon. The intensities of these transitions are consistent with inner-shell excitation from the AR XVII 1s2s 3 S and 1s2p 3 P metastable levels. This implies that the Ar XVII ionisation stage is overheated and is undergoing transient ionisation in the core plasma.