Scientists find way to make the world's largest laser even more powerful

Physicists at the Lawrence Livermore National Laboratory (LLNL) have discovered an unexpected and relatively simple way to increase the efficiency of the National Ignition Facility (NIF), the world's largest thermonuclear fusion device. According to the research, changing the polarization characteristics of the laser radiation could not only increase the system's power but also take its reliability to a new level. This is reported by Ixbt.com news reports.

The NIF device operates using 192 laser beams. These beams must be precisely directed through holes only 3 millimeters in diameter into a 2 centimeter cavity. Here, the extreme temperature and pressure required for a thermonuclear reaction are created. Inside the plasma, the beams interact with each other and redistribute energy. Physicists call this process "cross-beam energy transfer" (CBET).

Switching from linear to circular polarization

Currently, the device uses linear polarization. However, according to ixbt.com, scientists propose using circular polarization instead. Computer simulation results showed that circular polarization reduces the energy difference between beams entering at the same angle. This, in turn, makes the thermonuclear fusion process more stable.

One of the most important advantages of the new method is the reduction of the backscatter effect. This effect causes instabilities that can damage expensive optical components in the laser system. According to lead researcher Pierre Michel, reducing backscatter allows the laser to operate at significantly higher powers.

However, implementing this idea in practice presents specific challenges. Converting linear light to circular polarization requires a special quarter-wave plate. Jean-Michel Di Nicola, chief engineer of the NIF laser systems, noted that there is currently no easy way to produce such an element with the size and characteristics required for a massive device like the NIF.

Metasurface technology and future plans

To solve the problem, scientists are considering the use of patented metasurface technology. Although the results published in the journal Physics of Plasmas are currently based on theoretical calculations, they are considered very important for the future of thermonuclear energy. The next stage of experiments is planned at the more compact Jupiter Laser Facility.

If this discovery is confirmed in practice, it will be possible to significantly increase the efficiency of inertial confinement fusion simply by changing the light polarization. This would bring humanity one step closer to the dream of having an infinite and clean energy source.