This week, scientists from the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in California, achieved a revolutionary breakthrough in the pursuit of a “near-limitless, safe, clean” source of energy: fusion ignition without thermonuclear detonation. The U.S. Department of Energy (DOE) and DOE’s National Nuclear Security Administration (NNSA) announced the achievement in a statement in which the U.S. Secretary of Energy Jennifer M. Granholm referred to it as a “landmark” in science. This landmark involved creating more energy than the laser energy used to trigger the process. While the scientists have experimentally proved inertial fusion energy (IFE) in principle, the technology that would allow it to be used at a commercial scale, is still decades away. 

What is Nuclear Fusion?

Nuclear fusion is the process that powers the Sun and stars. Nuclear fusion involves the collision or less dramatically, the fusion or merging of two light nuclei to create one larger nucleus, and in the process, releasing a large amount of energy. This is because the total mass of the new nucleus is lower than the sum of the mass of the original two nuclei. The difference between two is released as energy, in accordance with Albert Einstein’s mass-energy equivalence equation, E=mc2. In the fusion reaction conducted by the NIF, 3.15 megajoules (MJ) of energy was produced, in a split second, from nuclear fusion, from 2.05 MJ of laser energy. 

Source: U.S. Department of Energy

Nuclear fusion can be driven with a variety of elements in the periodic table. Nevertheless, researchers are focused on the deuterium-tritium (DT) fusion reaction, which produces a neutron and helium nucleus. In doing so, more energy is released than with most other fusion reactions. 

Significance of Nuclear Fusion

Being able to use nuclear fusion to power machines, would improve national defense as well as giving the United States a new source of energy. In the future, power for everyday use could be produced from fusion power plants such as tokamaks and stellarators. In addition, DT reactions can be achieved at much lower temperatures than other fusion reactions.

Nuclear fusion was first proposed in 1920 by Arthur Eddington, who suggested that hydrogen-helium fusion was the main source of stellar energy. Since the 1960s, scientists from more than 50 countries have pursued nuclear fusion, without showing any positive energy gain, something that is called, “ignition”. Dr. Robbie Scott, who participated in the project and is from the Science and Technology Facilities Council’s (STFC) Central Laser Facility (CLF) Plasma Physics Group, described the achievement as a “momentous achievement”. He added that “Fusion has the potential to provide a near-limitless, safe, clean, source of carbon-free baseload energy”. LLNL Director, Dr. Kim Budil called nuclear fusion, “one of the most significant scientific challenges ever tackled by humanity, and achieving it is a triumph of science, engineering, and most of all, people”. 

Nevertheless, it will take a few decades before we enjoy the benefits of this important result. While important, the experiment only produced about 0.79 kilowatt-hours (kWh) of energy. If you consider that 0.4MJ is equivalent to about 0.1kWh, and that you need about 2 kWh of energy to power an electric dishwasher for every load, the energy produced was very little. 

Scientists will work to increase the energy gain from fusion, achieve fusion on a more frequent basis, and at a cost that is commercially accessible. At present, the LLNL can only replicate its results once a day, whereas, in the future, it should be able to achieve ignition 10 times per second. If they can do that, nuclear fusion will power America and the world.