Additional Information about the Chemistry of Precipitates by Variation of the Scattering Contrast in the SANS and SAXS Experiment

Small-angle neutron scattering (SANS) experiments were performed at KWS2 facility of the KFA Jülich for investigating the defect structures, which are produced by neutron irradiation in Russian Cr-Mo-V alloyed reactor pressure vessel steel. Irradiation and post-irradiation annealing considerably change both SANS intensity and its course in the Guinier plot, which was analysed by the Glatter method. As a rule, bimodal size distribution functions were found with a first maximum at a radius of 1-2 nm and a second maximum at 6-8 nm. Irradiation increases the first maximum annealing reduces it.