Simulation Result (IMAGE) National Institutes of Natural Sciences Caption Simulation results which indicate that the increase in collision frequency brings about the decrease in the trapped electron instability. In a helical LHD plasma (left) as well as in a tokamak plasma (right), as collision frequency increases in a higher density plasma, the strength of instabilities in hydrogen plasma (red) and in deuterium plasma (blue) reverses. Instabilities weaken (that is, are stabilized) in plasmas with larger ion mass, and turbulence is suppressed. Dots and dashed lines indicate, respectively, the quantity of heat loss and the collisionality regime which is relevant to the fusion reactors. Credit Dr. Motoki Nakata Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.