Researchers build spherical dynamo to mimic Earth’s interior

Nature : Although self-sustaining dynamos occur readily in stars and planets, none has yet been achieved in the lab. That may change next year when a project at the University of Maryland, College Park, is scheduled to go on line. Housed in a cavernous warehouse at the university, the Three Meter Experiment consists of a 3-meter-diameter ribbed sphere, inside of which is a 1-meter sphere surrounded by thousands of kilograms of liquid sodium heated to about 105 °C. When the device is turned on, it will whirl around and churn the electrically conducting fluid, which researchers hope will generate a self-sustaining electromagnetic field similar to Earth’s. The project could shed light on how rotational forces in Earth’s core deflect flows of electrically conducting liquid into a configuration that produces a magnetic field with north and south poles, writes Susan Young for Nature.