Effect of inhomogeneities on spiral wave dynamics in the Belousov-Zhabotinsky reaction.

We examine the effects of controlled, slowly varying spatial inhomogeneities on spiral wave dynamics in the light sensitive Belousov-Zhabotinsky chemical reaction-diffusion system. We measure the speed of the grain boundary that separates two spirals, the speed of the lower frequency spiral being swept away by the grain boundary, and the speed of the slow drift of the highest frequency spiral. The grain boundary speeds are shown to be related to the frequency of rotation and wave number of the spiral pattern, as predicted from analysis of the complex Ginzburg-Landau equation [M. Hendrey, Phys. Rev. Lett.10.1103/PhysRevLett.82.859 82, 859 (1999); M. Hendrey,, Phys. Rev. E10.1103/PhysRevE.61.4943 61, 4943 (2000)].