DESTABILIZATION OF 3-DIMENSIONAL ROTATING CHEMICAL WAVES IN AN INHOMOGENEOUS BZ REACTION

The mechanism of destabilization of rotating vortices of chemical acti vity (scroll waves) induced by a parameter gradient is studied in a ge l-immobilized Belousov-Zhabotinsky (BZ) reaction. Destabilization occu rs when a temperature gradient above a certain critical value is appli ed parallel to the filament of an initially simple scroll wave. Direct observation of the vortex filament using video imaging provides evide nce that the mechanism of destabilization involves the spontaneous cre ation of a helical perturbation of the filament which grows and eventu ally collides with the boundaries of the medium, fragmenting into mult iple filaments. Evidence is presented that is phenomenon is the result of an instability caused by a gradient-induced filament drift.