X-ray absorption spectroscopy of X-pinch plasmas

Summary form only given. X-ray absorption spectroscopy is a powerful diagnostic technique for determining the charge state, temperature and density of plasmas under a wide range of conditions and situations. It has been employed recently to study the core-corona system generated in electrically exploded wires and wire array Z-pinches. Using an X-pinch as the source of probing radiation and a spherically bent quartz crystal as the spectral analyzer as in those experiments required the object to be uniformly elongated in one direction. The important central part of an X-pinch is localized in the limited space and so, to probe it using x-ray radiation from an auxiliary source, a complicated focusing x-ray optical scheme must be used and is under development now. In the work reported here, we observed “self-absorption” spectra of hybrid X-pinches (HXP) when the continuum radiation from the X-pinch hot spot is absorbed in the surrounding hot spot plasmas or in the trailing material of the X-pinch neck. To extend the choice of materials that can be used in HXPs we developed hollow tube loads that are filled by powder or fine grains of salt. We have tested twisted Al wires wetted with the melt sulfur and single Ti and Mo wires covered by mixtures of epoxy or super-glue with CaCl 2 salt grains. Using ELICS and Johann spectrographs we recorded intense K-shell spectra containing both emission and absorption spectral lines. Plasma parameters were estimated using Prizm program.