This applet recreates my old X-spiral program which used to run on Unix machines under X-windows.

Click the Start button to initiate a plane wave from the left.

The setting, functionality and buttons are the same as in the 2D FHN applet and we reffer to it for their explanation.

Things to do:

• Besides the things one can do with the 2D FHN model this model can illustrate the breakup of spiral waves as seen in this movie by APD oscillations as observed in the 1D ring applet.
• Oscillations of APD occure when the model has a restitution with slope greater than one and the spiral wave period is small and intersects the resitution at points where the slope is greater than one (see the restitution applet ).
• In this model the period of rotation can be decreased by increasing vstar and/or xm . For example start the applet and as in the 2D FHN applet initiate a spiral wave by clicking the Reset h button when the plane wave is in the center of the tisse (wait a couple of rotations for the spiral wave to reach a steady state). Then one can induce breakup by APD oscillations by slowly increasing vstar (using 0.01 value steps) and observe the oscillatons and breakup as one goes to a value close to .6 for vstar . Similarly one can increase xm (using step values of 1) and observe the breakup and the complex spatiotemporal organization.
• We recomend to use the Trace on button and visualize the AP oscillatons on the recording.