Nuclear fusion breakthrough confirmed

A major breakthrough in nuclear fusion has been confirmed by the National Ignition Facility at Lawrence Livermore National Laboratory in California, little over a year since the lab successfully achieved 1.3 megajoules of energy for a fraction of a second.

After a year of painstaking work, the NIF has published its work in three peer-review papers.

Nuclear fusion is the process that powers the Sun and other stars. Heavy hydrogen atoms collide with enough force that they fuse together to form a helium atom, consequently releasing enormous amounts of energy as a byproduct.

Ideally, once the hydrogen plasma "ignites," the fusion reaction becomes self-sustaining, with the fusions themselves producing enough power to maintain its temperature without external heating.

This has long been a dream of physicists and utopian settings often present fusion as the solution to all energy needs.

This vision of abundant clean energy took a major step forward on Aug. 8, 2021, when 192 laser beams pumped vastly more power than the entire U.S. electric grid into a small gold capsule and ignited, for a fraction of a second, the same thermonuclear fire that powers the Sun.

The experiment was enabled by focusing these lasers, roughly the size of three football fields, into a target nearly the size of a BB, which produced a hot-spot the diameter of the human hair. The result, generation of more than 10 quadrillion watts of fusion power for 100 trillionths of a second.

You can read about fusion power and the importance of lasers in its ignition in The dream of fusion made real with boron in the April 8, 2020, edition of Metal Tech News.

"This result is a historic step forward for inertial confinement fusion research, opening a fundamentally new regime for exploration and the advancement of our critical national security missions," said Lawrence Livermore National Laboratory Director Kim Budil during the announcement in 2021. "It is also a testament to the innovation, ingenuity, commitment and grit of this team and the many researchers in this field over the decades who have steadfastly pursued this goal."

If mankind could harness this reaction to generate electricity, it would be one of the most efficient and least polluting sources of energy possible. No fossil fuels would be required as the only fuel would be hydrogen, and the only byproduct would be helium, which is used in many industries and of which supplies are beginning to dwindle.

However, the problem with fusion energy at the moment is that we do not have the technical capabilities to harness its power. Hence, scientists and researchers worldwide have been working on a solution for decades.

"The record shot was a major scientific advance in fusion research, which establishes that fusion ignition in the lab is possible at NIF," said Omar Hurricane, chief scientist for LLNL's inertial confinement fusion program. "Achieving the conditions needed for ignition has been a long-standing goal for all inertial confinement research and opens access to a new experimental regime where alpha-particle self-heating outstrips all the cooling mechanisms in the fusion plasma."

In the experiments performed to reach this ignition result, researchers heated and compressed a central "hot spot" of deuterium-tritium – hydrogen atoms with one and two neutrons, respectively – fuel using a surrounding dense piston also made from deuterium-tritium, creating a super hot, super pressurized hydrogen plasma.

"Ignition occurs when the heating from absorption of α (Alpha) particles [two protons and two neutrons tightly bound together] created in the fusion process overcomes the loss mechanisms in the system for a duration of time," the authors penned in a paper published to "Physical Review E."

This is one of the three peer-reviewed papers that acknowledged the years of research and thousands of man hours dedicated to improving and perfecting the process to achieve ignition – more than 1,000 authors are included in the "Physical Review Letters" paper.

Since the August 2021 record shot, the researchers have been executing a series of experiments to repeat the performance and to understand the experimental sensitivities in this new regime. Despite not achieving the same energy yield as the 2021 experiment, all of them reached higher energies than previous trials.

Data from these follow-ups have continued to aid researchers to further streamline the fusion process and further explore nuclear fusion as a real option for electricity generation in the future.

"It is extremely exciting to have an 'existence proof' of ignition in the lab," said Hurricane. "We're operating in a regime that no researchers have accessed since the end of nuclear testing, and it's an incredible opportunity to expand our knowledge as we continue to make process."