No more zigzags: Scientists uncover mechanism that stabilizes fusion plasmas
(PHYSorg.com Physics)

Sawtooth swings-up-and-down ripples found in everything from stock prices on Wall Street to ocean waves-occur periodically in the temperature and density of the plasma that fuels fusion reactions in doughnut-shaped facilities called tokamaks. These swings can sometimes combine with other instabilities in the plasma to produce a perfect storm that halts the reactions. However, some plasmas are free of sawtooth gyrations thanks to a mechanism that has long puzzled physicists.