The US Department of Energy announced an accomplishment in nuclear fusion that will go down in history – scientists have produced more energy in fusion than what was used to activate it.
The feat, called ‘net energy gain,’ has been the holy grail of scientists who have been on a decades-long quest to harness the same energy that powers the sun and stars
A team of scientists made the breakthrough at the Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) in California on December 5, which houses a sports stadium-sized facility equipped with 192 lasers.
The experiment saw the high-energy lasers converge on a target about the size of a peppercorn, heating a capsule of hydrogen to more than 180 million degrees Fahrenheit and ‘briefly simulating the conditions of the sun,’ said Lawrence Livermore National Laboratories Director Dr Kim Budil.
Energy Secretary Jennifer Granholm called the breakthrough a ‘landmark achievement.’
Granholm said scientists at Livermore and other national labs are working on research to help the US ‘solve humanity’s most complex and pressing problems, like providing clean power to combat climate change and maintaining a nuclear deterrent without nuclear testing.’
For the first time, scientists have produced more energy in fusion than what was used to activate it
Nuclear fusion is the process by which two light atomic nuclei combine to form a single heavier one while releasing massive amounts of energy.
In the case of Earth’s sun and the stars in space, nuclei need to collide with each other at extremely high temperatures, more than ten million degrees Fahrenheit.
The high temperature gives the nuclei enough energy to overcome their mutual electrical repulsion.
Once the nuclei come within a very close range of each other, the attractive nuclear force between them will outweigh the electrical repulsion and allow them to fuse.
For this to happen, the nuclei must be confined within a small space to increase the chances of collision.
Energy Secretary Jennifer Granholm (center) called the breakthrough a ‘landmark achievement.’ She was joined by scientists who conducted the groundbreaking experiment
The extreme pressure produced by its immense gravity creates the conditions for fusion in the sun.
WHAT IS NUCLEAR FUSION? Nuclear fusion is considered a potentially limitless source of clean energy created by the same core processes inside the sun.
Using intense heat, magnetic fields and pressure, the nuclei of lighter elements are fused together to create heavier elements, releasing energy in the process.
By containing this star-like process in specially designed reactors, engineers can fuse hydrogen atoms together to produce helium, harnessing the clean energy produced and potentially cutting dependency on fossil fuels.
For the reaction to take place, the super-heated gas – in a plasma state – is subjected to pressure, which essentially squeezes the atoms together and forces them to react.
Unlike fission, fusion carries less risk of accidents or the theft of atomic material.
Nuclear fission has been done and occurs when a neutron slams into a larger atom, forcing it to excite and split into two smaller atoms.
This is what happens in nuclear power plants.
But nuclear fusion has been a sought-after achievement for nearly 70 years.
The team pulled inspiration from researchers in the 1960s that theorized lasers could induce fusion in a laboratory.
And this kickstarted the decades-long work to develop those lasers and optics, diagnostics, target fabrication, computer modeling and simulation and experimental design.
These lasers, the world’s largest and most energetic system, used in the experiment can create temperatures and pressures like those in the core of stars and giant planets, along with inside exploding nuclear weapons.
The team used 2.1 megajoules of energy to create the reaction conditions, replicating how the sun is powered.
This resulted in an output of 3.15 megajoules – a gain of around 150 percent.
‘Ignition allows us to replicate for the first time certain conditions that are only found in the stars and sun,’ Granholm said Tuesday.
‘This milestone moves us one significant step closer to the possibility of zero carbon abundant fusion energy powering our society.’
She opened the live briefing with the statement that ‘this is what it looks like for America to lead.’
While Tuesday’s announcement is a step toward clean energy, the scientists are not blind to the work still ahead.
Budil said there are still ‘significant hurdles’ to overcome before the technology can be available commercially.
‘I think it’s moving into the foreground — and probably with concerted effort and investment, a few decades of research on the underlying technologies could put us in a position to build a power plant,’ she added.
Net energy gain has been the holy grail for scientists, as fusion happens at such high temperatures and pressures that it is incredibly difficult to control.
Billions of dollars and decades of work have gone into fusion research that has produced exhilarating results – for fractions of a second.
Riccardo Betti, a professor at the University of Rochester and expert in laser fusion, said an announcement that net energy had been gained in a fusion reaction is significant.
National Nuclear Security Administration Deputy Administrator for Defense Programs Dr. Marvin Adams held up the capsule that was heated to more than 180 million degrees by the powerful lasers
All of the energy of NIF’s 192 beams is directed inside a gold cylinder called a hohlraum, which is about the size of a dime. A tiny capsule inside the hohlraum contains atoms of deuterium (hydrogen with one neutron) and tritium (hydrogen with two neutrons) that fuel the ignition process
But he said there is a long road ahead before the result generates sustainable electricity.
He likened the breakthrough to when humans first learned that refining oil into gasoline and igniting it could produce an explosion.
‘You still don’t have the engine and you still don’t have the tires,’ Betti said. ‘You can’t say that you have a car.’
White House science adviser Arati Prabhakar, appearing with Granholm, called the fusion ignition ‘a tremendous example of what perseverance really can achieve’ and ‘an engineering marvel beyond belief.”
Proponents of fusion hope that it could one day produce nearly limitless, carbon-free energy, displacing fossil fuels and other traditional energy sources.
Producing energy that powers homes and businesses from fusion is still decades away. But researchers said it was a significant step nonetheless.
Michael Mann, with the Department of Earth and Environmental Science at the University of Pennsylvania, took to Twitter to share his skepticism on the announcement.
He shared that the fusion breakthrough is not enough to eliminate the need for fossil fuels just yet.
Scientists across the globe are rejoicing at news coming out of the US that the ‘holy grail’ of unlimited clean power is within touching distance. For the first time ever, experts have gained more energy from a controlled nuclear fusion reaction than they put in. Pictured is how a reactor works, based on one developed by UK firm Tokamak Energy
Pictured is the capsule used in the experiment. The team used laser capable of creating the inside of a nuclear weapon
Scientists at the Lawrence Livermore National Laboratory in California (pictured) used 2.1 megajoules of energy to create the conditions for the reaction, which replicates the reaction that powers the sun, and from that, they received 3 megajoules
‘That doesn’t mean it isn’t good news, but it does mean that it won’t play a significant role in decarbonizing our economy by 50% this decade, which is necessary to avert catastrophic >1.5C (3F) warming,’ Mann shared.
‘We can do that w/ existing renewables + storage/efficiency/conservation.’
The ultimate goal, still years away, is to generate power the way the sun creates heat by pushing hydrogen atoms so close to each other that they combine into helium, which releases torrents of energy.
A single cupful of that substance could power an average-sized house for hundreds of years without carbon emissions.
That is why fusion is considered the holy grail of energy in a world with an ever-increasing demand for electricity and a deteriorating environment.
It merges atomic nuclei to create massive amounts of energy — the opposite of the fission process used in atomic weapons and nuclear power plants, which splits them into fragments.
HOW A FUSION REACTOR WORKSFusion is the process by which a gas is heated up and separated into its constituent ions and electrons.
It involves light elements, such as hydrogen, smashing together to form heavier elements, such as helium.
For fusion to occur, hydrogen atoms are placed under high heat and pressure until they fuse together.
The tokamak (artist’s impression) is the most developed magnetic confinement system and is the basis for the design of many modern fusion reactors. The purple at the center of the diagram shows the plasma inside
When deuterium and tritium nuclei – which can be found in hydrogen – fuse, they form a helium nucleus, a neutron and a lot of energy.
This is done by heating the fuel to temperatures in excess of 150 million°C and forming a hot plasma, a gaseous soup of subatomic particles.
Strong magnetic fields are used to keep the plasma away from the reactor’s walls, so that it doesn’t cool down and lose its energy potential.
These fields are produced by superconducting coils surrounding the vessel and by an electrical current driven through the plasma.
For energy production, plasma has to be confined for a sufficiently long period for fusion to occur.
When ions get hot enough, they can overcome their mutual repulsion and collide, fusing together.
When this happens, they release around one million times more energy than a chemical reaction and three to four times more than a conventional nuclear fission reactor.