A requirement for diagnosis of the ionization state in opacity measurements

An accurate independent diagnosis of the temperature and the ionization state of the sample plasmas is important to get a set of well-characterized opacity data in experiment. An analysis of using x-ray scattering was presented for this purpose. Information of the ionization state of the sample plasmas could only be clearly detected when both the Compton and Rayleigh features of the scattering spectra are detectable in one laser shot. Only those plasmas with a few bounded electrons left can provide such kind of scattering spectra. The requirements for using the x-ray scattering as diagnosis are rigorous. Under a radiation field produced by laser-heated hohlraum, only limited number of sample elements can be heated to the ionization state required. Careful design is needed to achieve an x-ray scattering experiment. This work can be helpful to establish a diagnostic flattop for the opacity experiments.