Combining Small Angle and Wide Angle X- Ray Scattering Techniques for In-situ Studies of Particle Formation Processes in Reactive Systems Using a New Detector Prototype

Introduction To date there are still many unknowns on how particles are formed from gas phase reactive systems such as combustion. It is possible to study particles in-situ using X-ray scattering techniques: Separate applications have shown that the size distribution of soot particle can be measured using Small-Angle X-ray Scattering (SAXS) [1-4] and particle structure with Wide-Angle X-ray Scattering (WAXS) [5,6]. Combining SAXS and WAXS would be the best choice for studying particle formation processes, because that allows one to understand how size and structure are coupled during the chain of events from the earliest steps of molecular clustering/growth to fully mature nanoparticles and soot. In recent work SAXS and WAXS detectors, containing one and 6 channels, respectively, were combined and operated synchronously [7]. Last year a new SAXS detector containing 20 channels was constructed and tested on the same type of flame systems. In this work we describe the latest results from these combined SAXS and WAXS measurements.