BOUNDARY-LAYER ANALYSIS OF A SPIRAL WAVE CORE - SPIRAL CORE RADIUS AND CONDITIONS FOR THE TIP SEPARATION FROM THE CORE BOUNDARY

The size of a spiral core is predicted on the basis of a boundary-laye r analysis of a spiral tip in the nonkinematic limit. Dependencies of a spiral core radius on medium parameters are found analytically and n umerically for two models of excitable media. It is shown that the cor e radius is determined by the conditions for the tip separation from a core boundary. It is found that a core radius depends on all currents that are active during a wave front formation associated with the dif fusion fluxes coupling neighboring elements of excitable media. Varyin g currents that activated only after wave front formation do not resul t in a significant altering of a spiral core radius.