Nuclear fusion is one step closer now. The energy that was harnessed in Interstellar movie could be a reality, thanks to a study by researchers at the Rochester University’s Laboratory of Laser Energetics (LLE). Researchers working on OMEGA Laser have found optimal conditions that could produce a fusion yield that is five times higher than the current trend.
The study was published in Physical Review Letters. It stated that the theory is still at the preliminary stage as its practicality has to be applied to, and scaled up at, the National Ignition Facility (NIF) at Lawrence National Laboratory in California.
The proposed LLE conditions could produce over 100 kilojoules (KJ) of fusion energy. Though 100 KJ is a small amount, it could pave the way for future fusion energy reactors.
“We have compressed thermonuclear fuel to about half the pressure required to ignite it. This is the result of a team effort involving many LLE scientists and engineers,” said Regan, the leader of the LLE experimental group.
If ignited, thermonuclear fuel would unleash copious amounts of fusion energy, much greater than the input energy to the fuel. Igniting a target is the main goal of the laser fusion effort in the United States.
Research at both LLE and NIF is based on inertial confinement, in which nuclear fusion reactions take place by heating and compressing—or imploding—a target containing a fuel made of deuterium and tritium (DT). The objective is to have the atoms collide with enough energy that the nuclei fuse to form helium nuclei and a free neutron, releasing significant energy in the process.
LLE and NIF use different methods to spark their fusion reactions. LLE uses the direct-drive method, which involves directing 60 laser beams at a millimetre-sized pellet of fuel. This method will compress the fuel to 10th of a millimetre, triggering ignition. Meanwhile, NIF uses an indirect method, directing 192 laser beams to a gold enclosure, where it is converted to X-rays.
In both the methods being explored at LLE and NIF, a major challenge is creating a self-sustaining burn that would ignite all the fuel in the target shells.
New improvements in direct-method approach include uniform targeting, improved target shell, better diagnostics and better image capturing. Such studies are an effort to bring us closer to making nuclear fusion a possibility.