Record-Breaking Nuclear Fusion Has Been Achieved on a Mini Scale Using Laser-Heated Nanowires

The ultra-high intensity laser and the chamber containing the target nanowires used in the micro-scale fusion experiments at Colorado State University. Advanced Beam Laboratory/Colorado State University

Nuclear fusion occurs when two light elements fuse together to form a heavier one, producing vast amounts of energy in the process. This reaction takes place in the center of stars, but scientists are also attempting to reproduce it on Earth in the hopes of creating a clean and essentially unlimited power source that could replace fossil fuels.

In order to achieve this aim, huge experimental reactors the size of stadiums have been constructed at various sites around the world housing lasers costing hundreds of millions of dollars. However, producing sustained nuclear fusion is incredibly difficult and progress in the field has been slow.

But making the process work on a small-scale could open the door to a number of other useful applications beyond energy generation.

Now, researchers from Colorado State University (CSU) have demonstrated nuclear fusion on a micro scale in a lab with record-breaking efficiency in generating neutrons—subatomic particles which have no charge. Their results are published in the journal Nature Communications.

For the study, which was led by Jorge Rocca, a professor in electrical and computer engineering at CSU, the scientists used a high-powered, ultrafast laser, which the team built themselves.

They fired laser pulses at tiny, invisible wires—known as nanowires—which instantly created hot and dense plasma—one of the four fundamental states of matter that does not occur freely on Earth. This plasma created a chain reaction of fusion events, producing helium and highly energetic neutrons in record-breaking quantities 500 times that of any similar previous experiments.

Being able to produce neutrons effectively on a micro scale could open the door to advances in fields such as neutron imaging—which is used to gain valuable insights into the structure and properties of materials—or it may contribute to our understanding of how lasers interact with matter.