Exclusive: Marvel Fusion lands $70M for laser-powered fusion bet

by with No Comment Tech

A scientist oversees a laser experiment.

Image Credits: Marvel Fusion

When it comes to fusion power, there are two basic approaches: One, create a small star here on Earth that’s held in place by powerful magnetic fields. Two, use intense lasers to make a succession of even smaller stars, but repeat the process several times per second.

Moritz von der Linden likes his odds with the latter. In a world racing to wean itself off fossil fuels, fusion power promises to be an effectively limitless supply of energy, using widely available materials to recreate conditions that are hotter than the surface of the sun.

But most analysts believe commercial fusion power is still at least a decade away, and it’s up against renewable energy and battery storage, which continue to grow cheaper by the year. “Fusion has to come fast and it has to come cheap,” the co-founder and CEO of Marvel Fusion told TechCrunch. “Otherwise nobody needs it, and nobody will be willing to pay for it.”

Marvel Fusion is one of several companies pursuing what’s known as inertial confinement fusion. It’s the same basic approach used at the National Ignition Facility, a Department of Energy lab which proved in 2022 that controlled fusion reactions could generate more power than it took to ignite them. That’s a helpful milestone for any startup chasing the thus-far elusive technology.

But where NIF’s lasers are based on decades-old designs, Marvel is using cutting-edge technology to improve its lasers’ power and efficiency. The startup will soon build a demonstration facility in collaboration with Colorado State University, where it hopes two 100-Joule lasers will prove its core technology. Shovels hit the dirt on October 16, and von der Linden expects it’ll be operational by early 2027.

Those lasers will fire faster than the blink of an eye — in the femtosecond range, or one billionth of second — bombarding a nanostructured target with photons that blast away its electrons and scatter the remaining positively charged ions. Those ions will then hit Marvel’s fuel, igniting a fusion reaction. Currently, the company is using a mix of mainly hydrogen and boron, though von der Linden says the company is taking a “mixed fuel” approach to keep its options open should a more advantageous combination come along.

Compared with NIF’s fuel pellet, which is ensconced in a one-centimeter gold hohlraum that takes two weeks to manufacture and load, Marvel’s fuel and target were designed for mass manufacturing. The fuel itself is solid at room temperature, making it simpler to handle than NIF’s fel, which relies on either gaseous or cryogenically frozen hydrogen isotopes. Marvel’s target is simpler, too, made of silicon, not gold.

“That was kind of an awakening,” von der Linden said. “When the physics guys found out silicon works better, the target guys were like, ‘Hallelujah! We can use standard lithography from chip manufacturing.’” At the dimensions Marvel intends to manufacture, about 50 to 80 nanometers per feature, the company can use semiconductor manufacturing equipment that’s up to a decade old. It can produce around 5,000 targets on a standard 300 millimeter wafer.

If the Colorado experiments go as planned, the company will increase both lasers’ energy in 2028 or 2029. To hit those milestones, Marvel recently raised €62.8 million in a Series B round, the company exclusively told TechCrunch. HV Capital led the round with participation from b2venture, BayernKapital, Deutsche Telekom, SPRIND, and Tenglemann Ventures. The company was also selected by the European Innovation Council for a €2.5 million grant and up to €15 million in equity investment, which if made will be an extension of this round.

Marvel’s first commercial-scale prototype should be finalized around 2032 or 2033, von der Linden said, and it will contain between 10 and 20 two-kilojoule lasers. “With 20 lasers, we have the ability to really engineer the acceleration of the ions.” Each will fire around ten times per second.

That’ll be the moment of truth. While the company’s Colorado facility will be a useful milestone, “it’s like driving a Ferrari with a two cylinder engine,” von der Linden said. “It will move, but it won’t do what it’s supposed to do,” which in Marvel’s case is generate useful amounts of power. If the full-scale prototype fires on all, er, lasers, then the startup has a chance of crossing the fusion finish line. The race is on.

WHAM! Nuclear fusion experiment hits new record for magnet strength

by with No Comment Tech

Jay Anderson and Kieran Furlong inspect the WHAM experiment at University of Wisconsin-Madison.

Image Credits: Amadou Kromah (opens in a new window)

A nuclear fusion experiment at the University of Wisconsin-Madison has set a record for the strongest steady magnetic field confining a plasma, ushering in new hope that forthcoming demonstration reactors will deliver on their promises to produce more power than they consume.

The new magnets came from Commonwealth Fusion Systems (CFS), a pioneering startup in the fusion industry which delivered the devices to UW-Madison’s WHAM experiment earlier this month. Once the WHAM team chilled the magnets down to operating temperature and applied a strong electrical current, the high-temperature superconductors produced a 17 tesla magnetic field. That’s more than twice as powerful as high-resolution MRI scanners use to image the human brain.

Strong magnets are essential for the type of fusion power being pursued by CFS and others. For every doubling of the strength of a magnetic field, the power output of one reactor design increases 16-fold.

WHAM has been operating for a few years, but “this was the first plasma with those new magnets,” said Kieran Furlong, co-founder and CEO of Realta Fusion. Realta was spun out of WHAM in 2022, but it still works closely with UW-Madison scientists and the experiment itself.

The previous record was held by MIT’s experimental reactor Alcator C, Furlong said.

Plasma held in the WHAM experimental fusion reactor.
Plasma held in the WHAM experimental reactor lasted only a fraction of a second, but it was enough to set a record.
Image Credits: Mason Yu/University of Wisconsin-Madison

WHAM’s record-breaking magnetic field is something of a full-circle moment that illustrates just how close-knit the fusion industry remains: Research on Alcator C and its successor, Alcator C-Mod, helped prove the physics that underpins CFS’s reactor and magnet designs.

CFS was spun out of MIT in 2018 to commercialize fusion power using a breakthrough magnet design. Both CFS and Realta are working to deploy reactors that use powerful magnetic fields to hold burning plasma in place so that hydrogen nuclei can fuse, a process that releases immense amounts of heat. CFS’s reactor is what’s known as a tokamak, which coerces plasma into a doughnut-like shape. 

Realta and WHAM, on the other hand, are working on a magnetic mirror design. In it, two strong magnets sitting some distance apart create a magnetic field that holds the plasma in a shape that looks like a Tootsie roll. The magnets compress the plasma at either end, and the hydrogen ions bounce back and forth in the fat part of the roll where they collide, fusing in the process and releasing heat.

WHAM will serve as a testbed for the mirror reactor design. Once enough is understood about it, Realta will build a demonstration reactor that it calls Anvil, which it anticipates completing later in the decade. It’ll be similar to WHAM, though larger, and in addition to providing more data on the reactor design, it’ll also provide a way for scientists and engineers to test how different materials will behave inside a working reactor. 

Following Anvil, Realta plans to build Hammer, an evolution of the design that will have not one but two magnets on each end. That’ll allow it to build longer reactors, which it expects will be able to provide more power.

Exclusive: Without this company’s technology, future fusion power plants might never light up

by with No Comment Tech

Plasma flows through an illustration of a tokamak fusion reactor.

Image Credits: John D / Getty Images

Proponents of nuclear fusion have long promised to create nearly limitless power here on earth by harnessing the same reaction that powers the sun. Today, fusion’s biggest hurdle is ensuring that any fusion power plant produces more power than it needs to operate. The second is ensuring that it has enough fuel to run.

Many fusion reactors are designed to run on a mix of two isotopes of hydrogen, deuterium and tritium. (Common hydrogen atoms have no neutrons; deuterium atoms have one, and tritium have two.) There’s plenty of deuterium, which can be found in seawater, but not nearly enough tritium, which is so rare that it essentially has to be manufactured.

“There’s only 20 kilograms of tritium anywhere in the world right now,” Kyle Schiller, CEO of Marathon Fusion, told TechCrunch. A single commercial-scale power plant will require a few kilograms just to start up, meaning the world has enough tritium for a dozen at most. His startup, which has been operating stealthily, thinks it has a solution to that problem.

Today, the world’s tritium supply is a waste byproduct of a small number of nuclear plants running on fission, the type of nuclear power that has been harnessed for energy since the middle of the 20th century. Assuming that scientists can harness nuclear fusion to create viable power on earth, the first fusion plants will use this supply. Future reactors will depend on the first crop of fusion power plants, which will be designed to generate additional fuel.

“Deployment of fusion devices is this doubling process,” said Adam Rutkowski, Marathon’s CTO. “You’re breeding enough tritium to maintain the steady state consumption by the device, but you also need to breed excess tritium to start up the next reactor.”

That breeding will take place when neutrons unleashed during fusion strike a blanket of lithium. The impact will release helium and tritium, and those products will then be routed out of the reactor core where they can be filtered. Some of the tritium will be injected back into the reactor, while another portion will be reserved as fuel for other reactors.

There’s existing equipment for the task, but it’s only useful for experimental work. It’s efficient and effective, but because experimental reactors run for short periods, it doesn’t have the throughput needed for a commercial power plant. To get to that point, the filtration systems will need “a few orders of magnitude improvement,” Schiller said.

That’s where Marathon hopes to come in. It’s working to refine a 40-year-old technology known as superpermeation that uses solid metal to filter impurities from hydrogen.

It works something like this: The hydrogen and other stuff that needs to be filtered out is first turned into a plasma, though not one as hot as inside the reactor. The mix is then pressed up against the metal membrane, which allows hydrogen (including tritium) to pass through while blocking everything else. The effect, known as superpermeation, also compresses the hydrogen, giving it the pressure needed to flow through the fuel injection systems.

“The whole idea here is just getting maximal throughput as fast as possible,” Rutkowski said.

Rutkowski and Schiller have been working on the problem for a couple of years now, receiving early support from the Department of Energy’s ARPA-E program and the Breakthrough Energy Fellows program. Recently, Marathon raised a $5.9 million seed round, the company exclusively told TechCrunch. The round was led by the 1517 Fund and Anglo American with participation from Übermorgen Ventures, Shared Future Fund and Malcolm Handley.

Marathon said it has letters of intent from both Commonwealth Fusion Systems and Helion Energy, two fusion startups which have raised $2 billion and $607 million, respectively.

Given that commercial fusion power is still years away — if it’s even possible — Marathon’s bet might seem a bit early. After all, only one fusion experiment has hit breakeven in the scientific sense, which discounts the facility’s overhead, something a commercial power plant can’t do. 

Schiller disagrees that his company is too far ahead of the curve. “We’ve been pretty continuously surprised over the last decade or so just how fast progress [with fusion] has gone,” he said. “I really think that if we wake up one morning and get to breakeven, we’re going to wish we had started even sooner.”

Update: Added details to further explain superpermeation.

WHAM! Nuclear fusion experiment hits new record for magnet strength

by with No Comment Tech

Jay Anderson and Kieran Furlong inspect the WHAM experiment at University of Wisconsin-Madison.

Image Credits: Amadou Kromah (opens in a new window)

A nuclear fusion experiment at the University of Wisconsin-Madison has set a record for the strongest steady magnetic field confining a plasma, ushering in new hope that forthcoming demonstration reactors will deliver on their promises to produce more power than they consume.

The new magnets came from Commonwealth Fusion Systems (CFS), a pioneering startup in the fusion industry which delivered the devices to UW-Madison’s WHAM experiment earlier this month. Once the WHAM team chilled the magnets down to operating temperature and applied a strong electrical current, the high-temperature superconductors produced a 17 tesla magnetic field. That’s more than twice as powerful as high-resolution MRI scanners use to image the human brain.

Strong magnets are essential for the type of fusion power being pursued by CFS and others. For every doubling of the strength of a magnetic field, the power output of one reactor design increases 16-fold.

WHAM has been operating for a few years, but “this was the first plasma with those new magnets,” said Kieran Furlong, co-founder and CEO of Realta Fusion. Realta was spun out of WHAM in 2022, but it still works closely with UW-Madison scientists and the experiment itself.

The previous record was held by MIT’s experimental reactor Alcator C, Furlong said.

Plasma held in the WHAM experimental fusion reactor.
Plasma held in the WHAM experimental reactor lasted only a fraction of a second, but it was enough to set a record.
Image Credits: Mason Yu/University of Wisconsin-Madison

WHAM’s record-breaking magnetic field is something of a full-circle moment that illustrates just how close-knit the fusion industry remains: Research on Alcator C and its successor, Alcator C-Mod, helped prove the physics that underpins CFS’s reactor and magnet designs.

CFS was spun out of MIT in 2018 to commercialize fusion power using a breakthrough magnet design. Both CFS and Realta are working to deploy reactors that use powerful magnetic fields to hold burning plasma in place so that hydrogen nuclei can fuse, a process that releases immense amounts of heat. CFS’s reactor is what’s known as a tokamak, which coerces plasma into a doughnut-like shape. 

Realta and WHAM, on the other hand, are working on a magnetic mirror design. In it, two strong magnets sitting some distance apart create a magnetic field that holds the plasma in a shape that looks like a Tootsie roll. The magnets compress the plasma at either end, and the hydrogen ions bounce back and forth in the fat part of the roll where they collide, fusing in the process and releasing heat.

WHAM will serve as a testbed for the mirror reactor design. Once enough is understood about it, Realta will build a demonstration reactor that it calls Anvil, which it anticipates completing later in the decade. It’ll be similar to WHAM, though larger, and in addition to providing more data on the reactor design, it’ll also provide a way for scientists and engineers to test how different materials will behave inside a working reactor. 

Following Anvil, Realta plans to build Hammer, an evolution of the design that will have not one but two magnets on each end. That’ll allow it to build longer reactors, which it expects will be able to provide more power.

Plasma flows through an illustration of a tokamak fusion reactor.

Exclusive: Without this company’s technology, future fusion power plants might never light up

by with No Comment Tech

Plasma flows through an illustration of a tokamak fusion reactor.

Image Credits: John D / Getty Images

Proponents of nuclear fusion have long promised to create nearly limitless power here on earth by harnessing the same reaction that powers the sun. Today, fusion’s biggest hurdle is ensuring that any fusion power plant produces more power than it needs to operate. The second is ensuring that it has enough fuel to run.

Many fusion reactors are designed to run on a mix of two isotopes of hydrogen, deuterium and tritium. (Common hydrogen atoms have no neutrons; deuterium atoms have one, and tritium have two.) There’s plenty of deuterium, which can be found in seawater, but not nearly enough tritium, which is so rare that it essentially has to be manufactured.

“There’s only 20 kilograms of tritium anywhere in the world right now,” Kyle Schiller, CEO of Marathon Fusion, told TechCrunch. A single commercial-scale power plant will require a few kilograms just to start up, meaning the world has enough tritium for a dozen at most. His startup, which has been operating stealthily, thinks it has a solution to that problem.

Today, the world’s tritium supply is a waste byproduct of a small number of nuclear plants running on fission, the type of nuclear power that has been harnessed for energy since the middle of the 20th century. Assuming that scientists can harness nuclear fusion to create viable power on earth, the first fusion plants will use this supply. Future reactors will depend on the first crop of fusion power plants, which will be designed to generate additional fuel.

“Deployment of fusion devices is this doubling process,” said Adam Rutkowski, Marathon’s CTO. “You’re breeding enough tritium to maintain the steady state consumption by the device, but you also need to breed excess tritium to start up the next reactor.”

That breeding will take place when neutrons unleashed during fusion strike a blanket of lithium. The impact will release helium and tritium, and those products will then be routed out of the reactor core where they can be filtered. Some of the tritium will be injected back into the reactor, while another portion will be reserved as fuel for other reactors.

There’s existing equipment for the task, but it’s only useful for experimental work. It’s efficient and effective, but because experimental reactors run for short periods, it doesn’t have the throughput needed for a commercial power plant. To get to that point, the filtration systems will need “a few orders of magnitude improvement,” Schiller said.

That’s where Marathon hopes to come in. It’s working to refine a 40-year-old technology known as superpermeation that uses solid metal to filter impurities from hydrogen.

It works something like this: The hydrogen and other stuff that needs to be filtered out is first turned into a plasma, though not one as hot as inside the reactor. The mix is then pressed up against the metal membrane, which allows hydrogen (including tritium) to pass through while blocking everything else. The effect, known as superpermeation, also compresses the hydrogen, giving it the pressure needed to flow through the fuel injection systems.

“The whole idea here is just getting maximal throughput as fast as possible,” Rutkowski said.

Rutkowski and Schiller have been working on the problem for a couple of years now, receiving early support from the Department of Energy’s ARPA-E program and the Breakthrough Energy Fellows program. Recently, Marathon raised a $5.9 million seed round, the company exclusively told TechCrunch. The round was led by the 1517 Fund and Anglo American with participation from Übermorgen Ventures, Shared Future Fund and Malcolm Handley.

Marathon said it has letters of intent from both Commonwealth Fusion Systems and Helion Energy, two fusion startups which have raised $2 billion and $607 million, respectively.

Given that commercial fusion power is still years away — if it’s even possible — Marathon’s bet might seem a bit early. After all, only one fusion experiment has hit breakeven in the scientific sense, which discounts the facility’s overhead, something a commercial power plant can’t do. 

Schiller disagrees that his company is too far ahead of the curve. “We’ve been pretty continuously surprised over the last decade or so just how fast progress [with fusion] has gone,” he said. “I really think that if we wake up one morning and get to breakeven, we’re going to wish we had started even sooner.”

Update: Added details to further explain superpermeation.