A Bonse–Hart ultrasmall angle x-ray scattering instrument employing synchrotron and conventional x-ray sources

A Bonse–Hart ultrasmall angle x-ray scattering (USAXS) instrument employing both synchrotron and conventional x-ray sources was constructed. The instrument could be used to determine the structure of systems with inhomogeneity sizes on the order of ∼1000 nm. The characteristics of the instrument by using synchrotron and conventional x-ray sources were compared. The use of synchrotron radiation showed much improved features not only in scattered intensity, but also in angular resolution. The scattered intensity was increased by a factor of about 20. Therefore weaker scattering systems could be investigated. By using the synchrotron radiation, the deficiency of the Bonse–Hart camera could be compensated. An angular scan containing ∼30 data points in the scattering angle region smaller than ∼2 mrad with reasonable signal-to-noise ratio could be completed within 5–10 min for samples with reasonable scattering power. Therefore, kinetic studies could be possible if the half time of structural development in a system is of the order of hours. For static experiments, a conventional x-ray source could be used more conveniently to obtain a scattering curve with similar quality as that by means of synchrotron radiation partially because the channel-cut crystals were not optimized for the synchrotron beam divergence and partially because alignments could be accomplished at a more leisurely pace using the conventional x-ray source.