Innovative technique could unlock mass production of fusion energy

View through the OMEGA laser’s 20-cm disk amplifiers at the Laboratory for Laser Energetics. Credit: University of Rochester/ J. Adam Fenster.

Imagine a world where we could harness the same power that lights up the sun and stars.

This is the idea behind fusion energy, a process that’s safe, clean, and could potentially provide an abundance of power. But creating this energy source on Earth is no easy task.

Scientists have been trying to find ways to use lasers to create fusion energy for over half a century.

The idea is to compress thermonuclear material with powerful lasers, raising its temperature until a point called ignition is reached.

At this stage, more energy comes out than goes in, which is the ideal condition for a fusion energy power plant.

Although this was achieved for the first time at the National Ignition Facility in 2022, making it work on a large scale for everyday use is still a challenge.

Now, researchers at the University of Rochester’s Laboratory for Laser Energetics (LLE) have shown for the first time a new method called dynamic shell formation, which could be an important step towards the goal of a fusion power plant.

In traditional fusion energy attempts, a small amount of hydrogen fuel is frozen into a spherical shell and then hit by lasers.

This heats up the fuel to incredibly high temperatures and pressures. When the shell collapses and ignites, fusion happens and a massive amount of energy is released.

But for a fusion power plant to work, we would need to produce nearly a million of these targets every day, which is both expensive and difficult with current methods.

The dynamic shell formation method, however, could be the solution. Instead of using a frozen shell, a droplet of liquid hydrogen fuel is injected into a foam capsule.

When the capsule is hit by lasers, it forms into a shell that implodes and causes ignition, just like in the conventional method. The advantage is that it uses liquid targets instead of frozen ones, which are easier and cheaper to produce.

The researchers, Igor Igumenshchev and Valeri Goncharov, successfully demonstrated this in a scaled-down experiment.

They used the lab’s OMEGA laser to shape a sphere of plastic foam that mimicked the density of the liquid fuel into a shell.

To create fusion using dynamic shell formation, future experiments will need lasers with longer and more powerful pulses. But for now, this is an encouraging step towards making fusion energy more practical.

“Combining this target concept with a highly efficient laser system that is currently under development at LLE will provide a very attractive path to fusion energy,” says Igumenshchev.

The day when we might be able to power our homes, schools, and cities with the same energy that lights up the stars could be getting closer.

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