X-ray spectroscopy and spectropolarimetry of high energy density plasma complemented by LLNL electron beam ion trap experiments

X-ray spectra of high energy density (HED) Z-pinch plasmas have been analyzed by means of a comprehensive kinetic modeling. A new diagnostic, x-ray spectropolarimetry, was applied to study anisotropy of Z-pinch plasma. This diagnostic is based on theoretical modeling of polarization-dependent spectra measured simultaneously by spectrometers with different sensitivity to polarization. Specifically, K-shell emission from Ti X-pinches was recorded simultaneously with identical LiF crystal spectrometers with the dispersion plane perpendicular and parallel to the discharge axis. Spectroscopic results from seven Ti X-pinch shots have been analyzed. Similar K-shell Ti polarization-dependent spectra generated by a quasi-Maxwellian electron beam at the LLNL EBIT-II electron beam ion trap have been studied. Further, the EBIT-II M-shell W spectra have proved to be important in the development of M-shell diagnostics of HED Z-pinch plasma. The advantages provided by electron beam ion trap data in the interpretation of...