Last month, we demonstrated high-rate alchemy: turning mercury into...
Marathon Fusion@MarathonFusion
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Oct 22, 2026
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Last month, we demonstrated high-rate alchemy: turning mercury into real, stable gold, beating CERN’s record by a factor of 10.
Last week, we enriched isotopes in the world’s most powerful plasma centrifuge, beating the Soviet record that stood for 40 years.
Now, we’re building a fusion reactor in San Francisco to achieve record power density.
Last week, we enriched isotopes in the world’s most powerful plasma centrifuge, beating the Soviet record that stood for 40 years.
Now, we’re building a fusion reactor in San Francisco to achieve record power density.
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Why? Because millions of lives depend on rare medical isotopes the world doesn’t have enough of. Adoption of targeted radiotherapies has gone exponential, and existing reactors can’t keep up.
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Power alone isn’t enough. The reactions need to be concentrated with incredible density.
To meet demand, you would have to:
- hit a target just 1 cm across,
- with a trillion neutrons,
- every second,
- continuously,
- for years on end.
That sounds wild, perhaps on the edge of impossible, and yet it is exactly what we plan to do!
To meet demand, you would have to:
- hit a target just 1 cm across,
- with a trillion neutrons,
- every second,
- continuously,
- for years on end.
That sounds wild, perhaps on the edge of impossible, and yet it is exactly what we plan to do!
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To get there, we have to scale incredibly fast.
Starting small, we’ll double power density, every single month, from here on out. We’ll soon climb orders of magnitude over the best fusion reactors out there today.
Starting small, we’ll double power density, every single month, from here on out. We’ll soon climb orders of magnitude over the best fusion reactors out there today.
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If we do pull it off, the implications extend beyond nuclear medicine.
Commercially deploying our first small fusion reactors matures the industrial base required for large fusion power plants to succeed.
Commercially deploying our first small fusion reactors matures the industrial base required for large fusion power plants to succeed.
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To get there, we’re assembling a team of the world’s best engineers, scientists and operators.
We’re a team of 28 and growing quickly. You don’t need a PhD to contribute (only a fifth of us do). What you do need is determination, creativity, and a history of outstanding execution on hardware projects.
We’re a team of 28 and growing quickly. You don’t need a PhD to contribute (only a fifth of us do). What you do need is determination, creativity, and a history of outstanding execution on hardware projects.
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Our team has already demonstrated incredible results.
In a recent experiment, we selectively compressed isotopes in a plasma centrifuge, separating them based on mass.
MIT Professor Dennis Whyte previously described this challenge as “one of the hardest things,” adding that after 13 years of asking his own students to come up with a solution, none were successful.
In a recent experiment, we selectively compressed isotopes in a plasma centrifuge, separating them based on mass.
MIT Professor Dennis Whyte previously described this challenge as “one of the hardest things,” adding that after 13 years of asking his own students to come up with a solution, none were successful.
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In 2025, we published a bold proposal to use fusion reactors for gold production.
And now we’ve done it: Mercury transmuted into stable gold, using fusion neutrons, at 10x the record set by CERN in 2025.
We’ve reduced alchemy to a series of difficult but tractable engineering problems.
And now we’ve done it: Mercury transmuted into stable gold, using fusion neutrons, at 10x the record set by CERN in 2025.
We’ve reduced alchemy to a series of difficult but tractable engineering problems.
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And we’ve already started producing our first medical isotopes. Making use of fusion neutrons, we transmuted zinc into radioactive isotopes of copper used in cancer diagnostics and cutting-edge therapies.
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How have we been able to move so quickly?
Because we've spent years quietly building the foundation these breakthroughs rest on.
Since 2023, we’ve been building the underlying capabilities necessary to scale: expertise in molten lithium handling, RF-driven ion generation, plasma diagnostics, vacuum system engineering, neutronics modeling, high power cathodes, and so much more.
Because we've spent years quietly building the foundation these breakthroughs rest on.
Since 2023, we’ve been building the underlying capabilities necessary to scale: expertise in molten lithium handling, RF-driven ion generation, plasma diagnostics, vacuum system engineering, neutronics modeling, high power cathodes, and so much more.
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If you’ve made it this far, you’ll enjoy the details on our website! Check out our work, and get in touch if you’d like to learn more.
marathonfusion.com
marathonfusion.com
