Probability of the emergence of helical precipitation patterns in the wake of reaction-diffusion fronts

TL;DR

This paper investigates the probabilistic emergence of helical precipitation patterns behind reaction-diffusion fronts, combining experimental observations with a model that links pattern formation to reaction conditions, scales, and noise.

Contribution

It introduces a model explaining how reaction conditions and noise influence the probability of helical pattern formation in precipitation processes.

Findings

Helical patterns appear with well-defined probabilities controlled by initial reagent concentrations.

The model links pattern probability to reaction front scales and noise amplitude.

Experimental data supports the model's predictions about pattern emergence.

Abstract

Helical and helicoidal precipitation patterns emerging in the wake of reaction-diffusion fronts are studied. In our experiments, these chiral structures arise with well-defined probabilities P_H controlled by conditions such as e.g., the initial concentration of the reagents. We develop a model which describes the observed experimental trends. The results suggest that P_H is determined by a delicate interplay among the time and length scales related to the front and to the unstable precipitation modes and, furthermore, the noise amplitude also plays a quantifiable role.