Advanced x-ray diagnostics based on an observation of high-energy Rydberg transitions from autoionizing levels in dense laser-produced plasmas - art.no. 063409

The application of x-ray spectroscopy methods enabled a space-resolved obse rvation of the high-energy Rydberg satellite series 1s2lnl'--> 1s(2)2l + h nu and the Ly(beta) satellites 2l3l'--> 1s2l +h nu in dense laser-produced plasmas. Ab initio atomic structure calculations including relativistic and QED effects show excellent agreement with the precise wavelengths measurem ents. Satellite transitions with n > 3 split into three distinct groups. Fo r n > 5, the transitions are found to merge with the Ly(beta) satellite tra nsitions 2l3l'--> 1s2l + h nu and the series limits approach the Ly(beta) l ine. This leads to emission on the red and even on the blue wing of the Ly( beta) line. Spatially and spectrally resolved intensity distribution discov ered strong spatial restrictions of the Rydberg satellite intensities near the target surface. On the contrary, all resonance lines show strong emissi ons up to 10-mm distance from the target and large optical thickness. This enabled us to develop essentially opacity-free and spatially localized temp erature diagnostics based on Rydberg satellite emission. Total x-ray emissi on spectra are established with the help of the MARIA Suite Of kinetic code s. The derived properties of the spectral distribution make the high-energy Rydberg satellites of general interest for the wide class of dense plasma experiments.