Time-resolved spectroscopic investigations of soft X-ray radiation from X pinches

Summary form only given. The X pinch is an intense source of X-ray radiation in the 1.5-8 keV range. Individual x-ray sources produced within an X pinch exist for <1 ns and are emitted from a source <1 mum in diameter. In the past, spectroscopic investigations of the soft X-ray radiation emitted from X pinches have largely been limited to time-integrated measurements. These measurements indicated electron temperatures of 500-1300 eV, depending on wire material, and in some cases densities in excess of 10/sup 22//cm/sup 3/. Additional measurements imply a volume power density> 10/sup 21/ W/cm/sup 3/ and a surface flux > 10/sup 16/ W/cm/sup 2/ for the X-ray source. Time-resolved spectroscopic measurements of the radiation from X pinches will be presented that use a spherically bent mica crystal (R = 100-186 mm) and a Kentech X-ray streak camera with time resolution of <100 ps in a slitless scheme. The spectra of the soft X-ray radiation from. Al, Ti, NiCr, Nb and Mo X pinches obtained using Bragg angles near 45 degrees will be presented. The large angle allows us to place the crystal far from the X pinch, thereby preventing damage to the crystal and allowing a large spectral range. The previous time-integrated spectra and numerical spectral modeling were used to guide our choice of spectral lines that have been viewed with the streak camera. We will present time-resolved estimates for the electron temperature and density based on line ratios in H-, He-, and Ne-like ion spectra and/or the presence or absence of specific density-sensitive spectral lines.