Fusion reactor design

Arms control robots, a new national facility, and accelerating the drive to bring the fusion energy that powers the sun and stars to Earth. These far-reaching achievements at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) made 2019 another remarkable year. Research at the only national laboratory devoted to fusion and plasma physics — the state of matter that makes up 99 percent of the visible universe — broke new ground in varied fields as vast as astrophysics and as tiny as nanotechnology.

A major issue with operating ring-shaped fusion facilities known as tokamaks is keeping the plasma that fuels fusion reactions free of impurities that could reduce the efficiency of the reactions. Now, scientists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have found that sprinkling a type of powder into the plasma could aid in harnessing the ultra-hot gas within a tokamak facility to produce heat to create electricity without producing greenhouse gases or long-term radioactive waste.

Creating a star on Earth requires a delicate balance between pumping enormous amounts of energy into plasma to make it hot enough for fusion to occur and preventing that heat from escaping. Now, physicists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have identified a method by which instabilities can be tamed and heat can be prevented from leaking from the plasma, giving scientists a better grasp on how to optimize conditions for fusion in devices known as tokamaks.

An obstacle to generating fusion reactions inside facilities called tokamaks is that producing the current in plasma that helps create confining magnetic fields happens in pulses. Such pulses, generated by an electromagnet that runs down the center of the tokamak, would make the steady-state creation of fusion energy difficult to achieve. To address the problem, physicists have developed a technique known as transient coaxial helicity injection (CHI) to create a current that is not pulsed.