Marconi, M. C., authorRocca, J. J., authorFilevich, J., author2007-01-032007-01-032004-04-15http://hdl.handle.net/10217/68108Unpublished manuscript, dated: April 15, 2004.We present experimental evidence showing that the contribution of bound electrons to the index of refraction can significantly affect soft x-ray laser interferograms of laser-created plasmas. We report picosecond resolution soft x-ray laser interferograms of Al laser-created plasmas that late in their evolution display negative fringe shifts in the plasma periphery. Simulated density maps show that this results from the dominant contribution of low charge ions to the index of refraction. If neglected, the presence of significant densities of low charge ions in laser-created plasmas may result in the overestimation of the measured electron density for most materials.born digitalreportsengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.Text