Spontaneous period-doubling cascade and chaos.

The simulation, in flow regime, of the chlorate-nitrous acid-iodine-iodide oscillating reaction has shown a new kind of dynamic behavior. In addition to bursts separated by increasing amplitude oscillations, at low input chlorate concentration and low flow rate a repetitive sequence of bifurcations presenting period-1 (regular oscillations), period-2 (double amplitude oscillations), period-4 (four amplitude oscillations), etc., followed by chaos, which is a period-doubling cascade, was observed. This sequence of bifurcations and chaos occurs between a cluster of bursts. However, this sequence of bifurcations, chaos and bursts occur spontaneously and keeps repeating without the change of any parameter of the system, which are the input concentrations and flow rate.