Neon photoionization experiments driven by Z-pinch radiation

Present-day Z-pinch experiments generate similar to2 x 10(21) erg/s peak po wer, similar to6 ns full-width at half-maximum X-ray bursts that provide ne w possibilities to study radiation -heated matter. This source is being use d to investigate the production of plasmas in which photoionization dominat es collisional ionization. Spectroscopic measurements of such plasmas can s erve to benchmark atomic physics models of the photoionized plasmas. Beyond intrinsic interest in the atomic physics, these models will be applied to the interpretation of data from the new generation of satellite X-ray spect rographs that will promote the understanding of accretion-powered objects s uch as X-ray binaries and active galactic nuclei. Moreover, this informatio n is needed for X-ray laser research. Our experiments use a 1-cm-scale neon gas cell to expose 10(18) atoms/cm(3) to an X-ray flux of -5 x 10(18) erg/ cm(2)/S. Thin mylar (1.5 mum) windows confine the gas and allow the radiati on to flow into the cell. The ionization is monitored with absorption spect ra recorded with crystal spectrometers, using the pinch as a backlight sour ce. In initial experiments we acquired an absorption spectrum from Li- and He-like Ne, confirming the ability to produce a highly ionized neon plasma. (C) 2001 Elsevier Science Ltd. All rights reserved.