What is a kink instability?

Take the good old rubber band again and start twisting it. At first the rubber band just twist along its length. But when it gets a certain twist it makes a kink on itself and a small bump starts to grow out perpendicular to the original length direction of the rubber band.

weak twist

kink

As the rubber band gets more twisted more kinks may develop. The magnetic field may experience the same transition when it becomes sufficiently twisted. The difference is that the magnetic field will not continue to become more twisted. Instead it reaches a situations where, as the kink starts forming, the field can reconnect and get rid of enough twist to become stable again. The energy lost due to the decrease in twist is released in a way that can heat the coronal plasma.

Return to the DC heating section.