Spin, Mirror, Spin: A Shortcut to Fusion Energy express
The race for fusion energy is like trying to bottle a lightning bolt. For decades, physicists have struggled to recreate on Earth the processes that power the Sun. The main challenge is getting light nuclei to fuse despite their mutual repulsion, while extracting more energy than was spent heating and confining the plasma.
This new work offers a surprisingly elegant solution. The device from the University of Texas at Austin works like a carousel that doesn't just spin the seats but also squeezes them from all sides. First, the plasma (a superheated gas of charged particles) is slowly warmed in this rotating magnetic mirror, like soup on a stove. Then comes a rapid compression from every direction at once: from the sides, top, and bottom. This double whammy sharply boosts density and temperature at the center, triggering an avalanche of fusion reactions.
The authors build on already completed experiments and patents. Their calculations show the method can get very close to the Lawson criterion — the coveted milestone after which a fusion reaction starts to pay for itself. A carousel that squeezes plasma might just be the shortcut to clean energy that humanity has been seeking since the mid-20th century.
The Lawson criterion is the product of plasma density, temperature, and energy confinement time. For a deuterium-tritium mixture, you need about $10^{20}$ particles per cubic meter multiplied by seconds, at temperatures of hundreds of millions of degrees.
In Liu Cixin's novel "The Three-Body Problem," the alien Trisolarans use a similar principle: they compress matter to monstrous densities to trigger fusion reactions in their miniature "stars."