Effect of the necking phenomenon on the optical properties of soot particles

- We examine the impact of connectors on the optical properties of soot particles.
- Small connections between primary particles can be neglected.
- Different connection types can be used interchangeably.

Fractal-like aggregates are commonly modeled as assemblies of spheres positioned in point contact only. The necking phenomenon is usually neglected. Such an approach has some advantages, e.g. faster light scattering simulation programs can be used, however, it may result in many additional errors and inaccuracies. In our study we try to approximate them and select the most suitable connection model. In our work we focus on the impact of the necking phenomenon on the optical properties of two and five monodisperse soot particles. The results show that small connections can be neglected. Different connection types (the cylindrical, the linear and the quadratic connector) can be used interchangeably, therefore, we recommend the most basic one (i.e. the cylindrical connector). Additionally, when particles are not positioned in point contact (they tend to overlap) this phenomenon should not be omitted due to its impact on the resulting scattering cross sections.