No-flux boundaries stabilize scroll rings in excitable media with negative filament tension

TL;DR

This paper demonstrates through numerical simulations that no-flux boundaries can stabilize scroll rings in excitable media with negative filament tension, preventing turbulence and enabling stable configurations.

Contribution

It shows that boundary interactions can suppress turbulence in scroll rings, leading to stable formations, which is a novel insight into controlling excitability patterns.

Findings

Boundary interaction suppresses scroll wave turbulence.

Stable scroll rings form near no-flux boundaries.

Conditions for observing stabilized scroll rings are discussed.

Abstract

Scroll rings in an unbounded excitable medium with negative line tension undergo an instability ending eventually in a "turbulent" state, known as scroll wave (Winfree) turbulence. In this paper we demonstrate by numerical simulations based upon the Oregonator model for the photosensitive Belousov-Zhabotinskii reaction (PBZR) that the Winfree turbulence is suppressed by the interaction of the scroll ring with a confining Neumann boundary. Instead of the Winfree turbulence a stable scroll ring forms due to the boundary interaction. Furthermore, we will discuss the conditions under which boundary-stabilized scroll rings could be observed in the PBZR, taking into account a light-induced excitability gradient in parallel to the scroll ring's symmetry axis.