Tallents, G. J., Gartside, L. M. R., Rossall, A. K., Wagenaars, E., Whittaker, D. S., Kozlova, M., Nejdl, J., Sawicka, M., Polan, J., Kalal, M. and Rus, B. (2011) Probing high energy density plasmas with X-ray lasers. In: X-Ray Lasers 2010. Springer Proceedings in Physics, 136 . Springer Netherlands, Dordrecht, pp. 271-279. ISBN 9789400711853

X-ray lasers can probe solid density plasmas as the critical density is well above the electron densities produced. We consider an experiment where interferometry has been utilized to provide phase information and transmission measurements for an extreme ultra-violet (EUV) laser beam at 21.2 nm probing longitudinally through a laser irradiated plastic (parylene-N) target. The transmission provides a good measure of ablation as hot plasma becomes transparent. We show that refractive indices significantly below the solid parylene-N and plasma refractive indices are produced in the warm dense plasma produced by laser irradiation