Boosting Fusion Performance with Lithium (IMAGE) American Physical Society Caption As more lithium is added (with increasing discharge number in yellow), the plasma light changes from red (from recycling of the deuterium fuel gas) to green (lithium emission from the edge of the plasma) and the overall (recycling) light levels decrease. Credit Princeton Plasma Physics Laboratory 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.