BLOGS

A view of the assembled experimental JT-60SA Tokamak nuclear fusion facility outside Tokyo, Japan. JT-60SA.ORG

Topics: Applied Physics, Economics, Energy, Heliophysics, Nuclear Fusion, Quantum Mechanics

Japan and the European Union have officially inaugurated testing at the world’s largest experimental nuclear fusion plant. Located roughly 85 miles north of Tokyo, the six-story JT-60SA “tokamak” facility heats plasma to 200 million degrees Celsius (around 360 million Fahrenheit) within its circular, magnetically insulated reactor. Although JT-60SA first powered up during a test run back in October, the partner governments’ December 1 announcement marks the official start of operations at the world’s biggest fusion center, reaffirming a “long-standing cooperation in the field of fusion energy.”

The tokamak—an acronym of the Russian-language designation of “toroidal chamber with magnetic coils”—has led researchers’ push towards achieving the “Holy Grail” of sustainable green energy production for decades. Often described as a large hollow donut, a tokamak is filled with gaseous hydrogen fuel that is then spun at immense high speeds using powerful magnetic coil encasements. When all goes as planned, intense force ionizes atoms to form helium plasma, much like how the sun produces its energy.

[Related: How a US lab created energy with fusion—again.]

Speaking at the inauguration event, EU energy commissioner Kadri Simson referred to the JT-60SA as “the most advanced tokamak in the world,” representing “a milestone for fusion history.”

“Fusion has the potential to become a key component for energy mix in the second half of this century,” she continued.

The world’s largest experimental tokamak nuclear fusion reactor is up and running, Andrew Paul, Popular Science.

A laser fusion power plant proposed by Longview Fusion Energy Systems would generate 1000 MWh or more of electricity. The plant would compress fusion fuel by using an indirect drive, the same approach used at the National Ignition Facility, which in December announced that it had produced ignition and gain, the first time that fusion researchers have attained those milestones.

Topics: Futurism, Lasers, Modern Physics, Nuclear Fusion

The attainment of fusion ignition and energy gain on the world’s most energetic laser late last year was indisputably a major scientific accomplishment. But the road to fusion as a viable source of energy will be a long one, if not a dead end. And if it does ultimately become a reality, most experts say that it is unlikely that a laser-driven fusion power plant will be based on the approach taken by the National Ignition Facility (NIF), where the fusion milestone occurred.

The December shot, which produced 1.5 times the 2 MJ of energy that was fired on the fusion fuel, has silenced skeptics who said that ignition could never be created by bombarding tiny capsules of deuterium–tritium fuel with lasers. (See “National Ignition Facility surpasses long-awaited fusion milestone,” Physics Today online, 13 December 2022.) “They have done something very important: demonstrating ignition and burn,” says Stephen Bodner, a retired head of the laser fusion branch at the US Naval Research Laboratory who once was a persistent critic of NIF’s approach.

And the milestone is likely to open the floodgates to new investments in the handful of startups that are pursuing inertial fusion energy (IFE). “I think you will see a proliferation of companies devoted to IFE or aspects of IFE because of this and because of investor interest,” says Todd Ditmire, a University of Texas at Austin physicist who is chief technology officer of Focused Energy, an IFE startup.

Yet despite the fanfare greeting the announcement, the fact is that the fusion energy yield from the successful shot amounted to less than 1% of the 300 MJ taken from the electricity grid to power NIF’s 192 beams. And the energy released was enough to boil about 10 tea kettles. Many experts say that economically viable fusion will require fusion reactions yielding energy gains of at least 100 times the energy deposited on the fuel capsule—two orders of magnitude greater than the NIF shot.

NIF success gives laser fusion energy a shot in the arm, David Kramer, Physics Today

National Ignition Facility operators inspect a final optics assembly during a routine maintenance period in August. Photo credit: Lawrence Livermore National Laboratory

Topics: Alternate Energy, Applied Physics, Climate Change, Energy, Global Warming, Lasers, Nuclear Fusion

After the heady, breathtaking coverage of pop science journalism, I dove into the grim world inhabited by the Bulletin of the Atomic Scientists on their take on the first-ever fusion reaction. I can say that I wasn’t surprised. With all this publicity, it will probably get the Nobel Prize nomination (my guess). Cool Trekkie trivia: the National Ignition Facility was the backdrop for the Enterprise's warp core for Into Darkness.

*****

This week’s headlines have been full of reports about a “major breakthrough” in nuclear fusion technology that, many of those reports misleadingly suggested, augurs a future of abundant clean energy produced by fusion nuclear power plants. To be sure, many of those reports lightly hedged their enthusiasm by noting that (as The Guardian put it) “major hurdles” to a fusion-powered world remain.

Indeed, they do.

The fusion achievement that the US Energy Department announced this week is scientifically significant, but the significance does not relate primarily to electricity generation. Researchers at Lawrence Livermore National Laboratory’s National Ignition Facility, or NIF, focused the facility’s 192 lasers on a target containing a small capsule of deuterium–tritium fuel, compressing it and inducing what is known as ignition. In a written press release, the Energy Department described the achievement this way: “On December 5, a team at LLNL’s National Ignition Facility (NIF) conducted the first controlled fusion experiment in history to reach this [fusion ignition] milestone, also known as scientific energy breakeven, meaning it produced more energy from fusion than the laser energy used to drive it. This historic, first-of-its-kind achievement will provide the unprecedented capability to support [the National Nuclear Security Administration’s] Stockpile Stewardship Program and will provide invaluable insights into the prospects of clean fusion energy, which would be a game-changer for efforts to achieve President Biden’s goal of a net-zero carbon economy.”

Because of how the Energy Department presented the breakthrough in a news conference headlined by Energy Secretary Jennifer Granholm, news coverage has largely glossed over its implications for monitoring the country’s nuclear weapons stockpile. Instead, even many serious news outlets focused on the possibility of carbon-free, fusion-powered electricity generation—even though the NIF achievement has, at best, a distant and tangential connection to power production.

To get a balanced view of what the NIF breakthrough does and does not mean, I (John Mecklin) spoke this week with Bob Rosner, a physicist at the University of Chicago and a former director of the Argonne National Laboratory who has been a longtime member of the Bulletin’s Science and Security Board. The interview has been lightly edited and condensed for readability.

See their chat at the link below.

The Energy Department’s fusion breakthrough: It’s not really about generating electricity, John Mecklin, The Bulletin of the Atomic Scientists, Editor-in-Chief

LAWRENCE LIVERMORE NATIONAL LABORATORY

Topics: Energy, Environment, Modern Physics, Nuclear Fusion, Nuclear Power

More than a decade ago, the world’s most energetic laser started to unleash its blasts on tiny capsules of hydrogen isotopes, with managers promising it would soon demonstrate a route to limitless fusion energy. Now, the National Ignition Facility (NIF) has taken a major leap toward that goal. Last week, a single laser shot sparked a fusion explosion from a peppercorn-size fuel capsule that produced eight times more energy than the facility had ever achieved: 1.35 megajoules (MJ)—roughly the kinetic energy of a car traveling at 160 kilometers per hour. That was also 70% of the energy of the laser pulse that triggered it, making it tantalizingly close to “ignition”: a fusion shot producing an excess of energy.

 “After many years at 3% of ignition, this is super exciting,” says Mark Herrmann, head of the fusion program at Lawrence Livermore National Laboratory, which operates NIF.

NIF’s latest shot “proves that a small amount of energy, imploding a small amount of mass, can get fusion. It’s a wonderful result for the field,” says physicist Michael Campbell, director of the Laboratory for Laser Energetics (LLE) at the University of Rochester.

“It’s a remarkable achievement,” adds plasma physicist Steven Rose, co-director of the Centre for Inertial Fusion Studies at Imperial College London. “It’s made me feel very cheerful. … It feels like a breakthrough.”

And it is none too soon, as years of slow progress have raised questions about whether laser-powered fusion has a practical future. Now, according to LLE Chief Scientist Riccardo Betti, researchers need to ask: “What is the maximum fusion yield you can get out of NIF? That’s the real question.”

Fusion, which powers stars, forces small atomic nuclei to meld together into larger ones, releasing large amounts of energy. Extremely hard to achieve on Earth because of the heat and pressure required to join nuclei, fusion continues to attract scientific and commercial interest because it promises copious energy, with little environmental impact.

With explosive new result, laser-powered fusion effort nears ‘ignition’, Daniel Clery, Science Magazine

The Fusion Rocket Concept. ITER

Topics: Mars, Nuclear Fusion, Space Exploration, Spaceflight, Women in Science

A physicist has come up with a new rocket engine thruster concept that could take people to Mars ten times more quickly.

The physicist in question, Fatima Ebrahimi, is the concept's inventor and is part of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL).

Ebrahimi's study was published in the Journal of Plasma Physics.

An engine thruster based on solar flares

One of the main differences between Ebrahimi's new rocket thruster concept and other space-proven ones is that hers uses magnetic fields to boost particles of plasma out of the back of the rocket. So far, space-proven ones use electric fields to boost plasma.

Plasma is one of the four fundamental states of matter and made of gas ions and free electrons. Our Sun is a burning ball of plasma that uses a fusion reaction, for instance.

New Rocket Thruster Concept to Take Humans to Mars 10 Times Faster, Fabienne Lang, Interesting Engineering

Illustration of the main elements of the lattice confinement fusion process observed. In Part (A), a lattice of erbium is loaded with deuterium atoms (i.e., erbium deuteride), which exist here as deuterons. Upon irradiation with a photon beam, a deuteron dissociates, and the neutron and proton are ejected. The ejected neutron collides with another deuteron, accelerating it as an energetic “d*” as seen in (B) and (D). The “d*” induces either screened fusion (C) or screened Oppenheimer-Phillips (O-P) stripping reactions (E). In (C), the energetic “d*” collides with a static deuteron “d” in the lattice, and they fuse together. This fusion reaction releases either a neutron and helium-3 (shown) or a proton and tritium. These fusion products may also react in subsequent nuclear reactions, releasing more energy. In (E), a proton is stripped from an energetic “d*” and is captured by an erbium (Er) atom, which is then converted to a different element, thulium (Tm). If the neutron instead is captured by Er, a new isotope of Er is formed (not shown).

Topics: Astrophysics, NASA, Nuclear Fusion, Propulsion, Space Exploration, Spaceflight

A team of NASA researchers seeking a new energy source for deep-space exploration missions recently revealed a method for triggering nuclear fusion in the space between the atoms of a metal solid.

Their research was published in two peer-reviewed papers in the top journal in the field, Physical Review C, Volume 101 (April 2020): “Nuclear fusion reactions in deuterated metals” and “Novel nuclear reactions observed in bremsstrahlung-irradiated deuterated metals.”

Nuclear fusion is a process that produces energy when two nuclei join to form a heavier nucleus. “Scientists are interested in fusion because it could generate enormous amounts of energy without creating long-lasting radioactive byproducts,” said Theresa Benyo, Ph.D., of NASA’s Glenn Research Center. “However, conventional fusion reactions are difficult to achieve and sustain because they rely on temperatures so extreme to overcome the strong electrostatic repulsion between positively charged nuclei that the process has been impractical.

Called Lattice Confinement Fusion, the method NASA revealed accomplishes fusion reactions with the fuel (deuterium, a widely available non-radioactive hydrogen isotope composed of a proton, neutron, and electron, and denoted “D”) confined in the space between the atoms of a metal solid. In previous fusion research such as inertial confinement fusion, fuel (such as deuterium/tritium) is compressed to extremely high levels but for only a short, nano-second period of time, when fusion can occur. In magnetic confinement fusion, the fuel is heated in a plasma to temperatures much higher than those at the center of the Sun. In the new method, conditions sufficient for fusion are created in the confines of the metal lattice that is held at ambient temperature. While the metal lattice, loaded with deuterium fuel, may initially appear to be at room temperature, the new method creates an energetic environment inside the lattice where individual atoms achieve equivalent fusion-level kinetic energies.

NASA Detects Lattice Confinement Fusion