Scientists at the Lawrence Livermore National Laboratory in Livermore, California published a study Wednesday revealing the creation of burning plasma, an advance toward self-sustaining fusion energy.
The research was published by nature, an international scientific journal, and authored by Alex Zylstra, Omar Hurricane and George B. Zimmerman.
San Jose State physics and astronomy professor Kenneth Wharton said achieving nuclear fusion is crucial to putting the world on a path to reduced greenhouse emissions as the climate crisis continues to grow.
“Someday we might have fusion power plants on Earth, producing energy without burning carbon and producing a lot less nuclear waste than a fission power plant,” Wharton said in an email. “Fusion is also inherently much safer than fission… if we can stabilize [fusion energy] soon, our descendants may be able to use fusion power on a long-term basis.”
Nuclear fusion is the process by which two light atomic nuclei combine to form a single, heavier nuclei while releasing massive amounts of energy, according to the International Atomic Energy Agency webpage.
SJSU associate physics professor Ehsan Khatami said fission splits a heavy atom such as uranium and breaks it into lighter atoms. He said fusion is the complete opposite because two lighter atoms combine to create larger atoms.
“In nuclear reactors, energy is produced by splitting atoms, however, the atoms that are produced can still be radioactive leading to a radioactive nuclear waste and that is the main problem we have with nuclear energy which is otherwise pretty efficient,” Khatami said in a Zoom call.
Achieving fusion energy isn’t easy because the strongly repulsive electric force between the positively charged nuclei prevent them from getting close together to collide and for fusion to occur, according to a Jan. 6 Vox article.
With global average temperatures rising and energy demands growing, the need for fusion is timelier than ever, according to the atomic energy webpage.
The Lawrence Livermore study used the world’s most energetic laser in the lab’s National Ignition Facility (NIF) to heat a small spherical pellet-sized hydrogen isotope hotter than the temperature of the sun’s core, according to a Jan. 27 TechRadar article.
TechRadar is a technology news and reviews site from around the world, according to its webpage.
The facility’s laser created necessary pressure to trigger the hydrogen’s fusion process, which then heated the material by a significant fraction of a megajoule, according to the same article.
A megajoule is a unit of energy measurement, according to Encyclopedia Britannica. SJSU assistant chemistry professor Nicholas Esker said NIF uses a small sphere filled with deuterium and tritium. The two isotopes are rare forms of hydrogen with more neutrons than hydrogen, so when “pushed together” they react in a way that produces helium. This is the same reaction that generates energy in the sun.
“To overcome the inherent [proton] repulsion, NIF uses [192] laser beams and by using light to push the material so close together, you get this proton and neutron to react,” Esker said in a phone call. “NIF is delivering a lot of energy to push them together and uniformly from all sides and angles. Once [the nuclei] gets close enough it can then ignite and react in a way to produce helium, which generates energy in our sun.”
He said getting a sustained fusion reaction is a big technical problem, but with the recent work at NIF in achieving burning plasma, it’s “a big gain and exciting news.”
The sun and other stars are powered by nuclear fusion, and if nuclear fusion can be replicated on Earth, it can provide limitless clean, safe and affordable energy to meet the world’s energy demand, according to the International Atomic Energy Agency webpage.
Unlike burning fossil fuels or the fission used in nuclear power plants, fusion offers the prospect of abundant energy without pollution, radioactive waste or greenhouse gases, according to a Jan. 26 Reuters article.
“For decades we've been able to cause fusion reactions to occur in experiments by putting a lot of heating into the fuel, but this isn't good enough to produce net energy from fusion," Alex Zylstra said in the study.
“Now, for the first time, fusion reactions occurring in the fuel provided most of the heating - so fusion is starting to dominate over the heating we did. This is a new regime called a burning plasma," Zylstra said. “Making fusion a reality is an enormously complex technological challenge, and it will require serious investment and innovation to make it practical and economical.”
