The Study of Ge L-shell Emission form Non-LTE Plasmas Using a Buried Layer Platform at the OMEGA Laser*

A buried layer platform has been used at the OMEGA laser to study the open L-shell spectra of non-local thermodynamic equilibrium plasmas (ne ~ few 10²¹ cm^-3, Te ~ 1- 2 keV) of mid Z materials. Studies have been done using a 250 µm diameter dot composed of a layer of 600 Å thick Sc between two 300 Å thick layers of Ge, in the center of a 1000 µm diameter, 10 µm thick beryllium tamper. Lasers heat the target from both sides for up to 3 ns. The size of the emitting volume was measured time-resolved with x-ray imaging (face-on and side-on). The radiant x-ray power was measured with a low-resolution absolutely calibrated x-ray spectrometer (DANTE). The time-resolved temperature was inferred from the Sc K-shell emission. The comparison of the Ge L-shell emission to synthetic spectra calculated using an atomic kinetics code at the measured temperature and density is discussed.