### Mass Fractal Aggregate model — Irena and Nika

Where: Rg is the Radius of gyration of the second (Large) level represents the size of the mass fractal aggregate. d p is Sauter mean diameter of a sphere of similar surface to volume ratio as the scattering primary particle (first, smaller level).; The value z which is one of the inputs of the 3D aggregate model, d min, and c are calculated by Unified fit tool in "Analyze results".