Absolute calibration of small angle neutron scattering data using strong coherent scattering

Typically, s ~ n a l l angle neut ron scat ter ing (SANS) d a t a is normalized t o a n absolut,e scale using secondary s tandards such a s water , polymers, silica gels, o r i rradiated aluminum. Er rors for this l r ~ e t h o d of calibration arise when t h e initial deterrllination or calculation of t h e standard 's scattering cross-section is n o longer valid due t o degrada t ion o r wavelength-dependent mult iple scat ter ing or detector efficiency effects. Here we i l lustrate how st,rong coherent scat ter ing can b e used t o exper i~nenta l ly nieasure t h e incident neu t ron bean1 intensity a n d t h u s serve a s a prinlary absolute ca l ib ra t , io~~. W e show h o w easily th i s procedure is imple~llented using a ternary microemn~ilsion a s a s t rong scat terer a n d compare i t s accuracy wi th solne o ther secondary s tandards com111only i n use. W e find t h a t t h e procedure is consistent wi th t h e o ther s tandards a n d should b e considered a viable al ternative when norlllalizing SANS measurement,s.