Fusion Reactors That Make Gold? Marathon Fusion Thinks So

A team of engineers from the San Francisco-based startup Marathon Fusion has introduced a novel method to convert byproduct neutrons from fusion into powerful transmutative pathways capable of producing gold. The new technology could be used to offset the cost of running these infinite energy-producing fusion systems and revolutionize energy production moving forward. Here’s what you need to know.

Alchemy

For centuries, humans have sought the dream of creating gold from other metals through alchemy. This practice originated in ancient Egypt. At the time, Egypt was known as Kemet, which roughly translates to black land. This name was given to the region due to its fertile, dark soil. From there, the Arabic word “al–kimiya” was derived, which later evolved into the term “alchemy” as the practice spread across Ancient China, India, and eventually Europe.

What many people get incorrect about alchemy is that it was more than a group trying to create gold from other metals. It was a philosophy. In the alchemical belief, gold was the most evolved metal. To create gold, the alchemist had to become the most evolved form of himself. In this way, alchemy was as much a spiritual journey as it was an early form of chemistry.

Alchemical Legends and Modern Dreams

Over the centuries, the concept of spiritual alchemy has evolved into today’s version of a gold-creating mad scientist, obsessed with transmuting base metals such as lead, tin, iron, copper, and mercury into gold. However, you can still find glimpses of their original motifs in literature, such as “The Alchemist” by Paulo Coelho and other works.

Source – GoodReads

Notably, Alchemy laid the foundation of modern science and chemistry. It was instrumental in helping to guide many famous inventors to make great discoveries. These creatives include Isaac Newton, Robert Boyle, and many other scientific and influential minds throughout history.

Philosopher’s Stone

In Alchemy, the highest level of understanding one could achieve was to create the philosopher’s stone. It was reported in alchemical folklore that this mythical item would enable an alchemist to transmute any metal into gold with ease. Additionally, the alchemist could create the elixir of life, which granted them instant healing capabilities according to the myths.

Modern-Day Transmutation Efforts

While it’s obvious that much of the history of alchemy is more myth than reality, there are some key factors that have emerged over the last decade that have highlighted the group’s dreams of creating gold from base metals. The science of transmutation has now been renamed chrysopoeia, and amazingly, scientists have already created gold.

A recent observation at CERN’s Large Hadron Collider by the ALICE collaboration detected a rare transformation of lead ions into gold ions during high-energy collisions. However, CERN emphasized that this is not a scalable or extractable form of gold — the gold atoms appear briefly and only in extremely specific experimental conditions. The team humorously noted that “this is not the philosopher’s stone of the alchemists.

Why Particle Accelerators Won’t Work

There are a few problems that these modern-day alchemists encountered on their journey. For one, the process required the use of the Large Hadron Collider. This massive particle accelerator requires a significant amount of energy to operate, and the gold produced can only be made at a maximum rate of about 89,000 nuclei per second, making it practically impossible to produce any amount of value.

Marathon Fusion Study

Keenly, a team of engineers from Marathon Fusion may have unlocked the key to true transmutation. Their paper¹, titled “Scalable Chrysopoeia via (n, 2n) Reactions Driven by Deuterium-Tritium Fusion Neutrons,” details a novel method to synthesize stable gold from mercury isotopes using the byproduct of atomic reactions in a specialized neutron multiplier layer of a fusion blanket that occurs within a Tokamak fusion reactor.

Tokamak Fusion Reactor

Tokamak Fusion reactors were invented in the 1950s by Soviet scientists. These toroidal reactors utilize powerful magnetic coils positioned around a doughnut-shaped chamber. This arrangement allows the magnets to compress hydrogen isotopes, tritium and deuterium, to form helium.

Source – Iter

Breeding Blanket

During the fusion process, subatomic particles called neutrons are released. These high-energy particles get caught in a fusion blanket called the breeding blanket. The breeding blanket acts as a neutron multiplier layer, which enables it to support future fuel cycles by enabling the creation of tritium and lithium.

Notably, during normal fusion, temperatures can exceed those of the center of the sun. At 100 million degrees Celsius, the neutrons create a deuterium-tritium fusion plasma. These plasma reactions can be used to create tritium fuel as lithium absorbs the neutrons.

Mercury Instead of Lithium

The Marathon Fusion team made a surprising discovery when they replaced the lithium with the isotope mercury-198. Notably, the engineers stated that the isotope was enriched to 90% as part of the process. This common isotope provides additional reactions during fusion.

Mercury-197

The engineers noted that after switching out the lithium for mercury, the subsequent fusion produced unstable mercury-197. This isotope is incapable of remaining in its state and deteriorates over days into another metal, stable gold-197, which is the natural yellow gold most people associate with the precious metal.

Marathon Fusion Study Test

To test their concept, the team conducted several OpenMC and gold production neutronics simulations. Their testing began with the team recreating a Tokamak Fusion reactor digitally. From there, the group set up the exact restraints of their testing. For example, the test assumed that the power plant would produce 1500 MWth power output.

Marathon Fusion Study Test Results

The Marathon Fusion Study test results corroborated the engineers’ theories. Their novel approach was capable of producing 2-5 tonnes of gold from mercury per gigawatt of electricity generated. The simulations also revealed some negative effects of creating gold from nuclear fusion.

Contaminated Gold

The testing showed that the process does leave some radioactive gold isotopes. Consequently, any gold created using this method will need to sit in storage for +18 years before it can be deemed safe. This delay period cannot be sped up without jeopardizing health. However, it can be noted that the gold could still be sold via paper while in storage, enabling nuclear power suppliers to generate additional revenue from day one of operations.

Marathon Fusion Study Benefits

There’s a long list of benefits that come alongside the ability to create gold from nuclear fusion byproducts. For one, this is the first time an economically viable business model for fusion energy has existed. In the past, the cost of operating, storing spent nuclear waste, and additional risks have led many to believe that nuclear fusion is only a viable solution under exact circumstances. This new approach offers an implementable, affordable, and scalable alternative to the market.

Additionally, Marathon Fusion’s gold production approach doesn’t negatively impact electricity production, meaning that it could help to defray operating costs for this expensive hardware. Also, through transmutation and neutron multiplication, there is an abundant supply of the isotope.

Added Revenue

One of the most significant benefits of this study is that it reveals how nuclear reactors can generate a lot of extra revenue without losing any operational capacity. Given the current price of gold, nuclear power plants could generate as much income from this approach as their primary business model, providing energy. Doubling the revenue of these businesses will make them more attractive and hopefully drive further adoption of this clean energy solution.

Fusion Gold Production at Scale

Another major milestone is the sheer amount of gold that this approach can produce. According to the study, the engineers were able to simulate the creation of  11,023 pounds of gold annually just from one gigawatt of power usage. These funds could one day be used to subsidize the deployment of terawatts of power without causing saturation.

Gold Market Values

There are some financial advantages above the ability to create and sell gold. For one, the scientists believe that by limiting their approach, combined with the 18-year decantamination period, the new gold won’t cause a sudden drop in prices. They cite that global gold mining yields roughly 3,500 tons per year, of which the 11 tonnes created by reactors a year won’t make a difference in terms of supply and demand.

Marathon Fusion Study Real-World Applications & Timeline:

There are a lot of applications for this technology. The obvious use is to create gold to make fusion power a more economically attractive solution. Gold is a vital component of today’s advanced electronics and financial systems. The ability to create this precious metal has long been a dream of scientists for centuries. Now, this dream is a reality.

Nuclear Batteries

The concept of nuclear batteries has taken flight. These power supplies create energy by converting the decaying isotopes into electricity. Unlike reactors that rely on a chain reaction, nuclear batteries have a single slow decay that results in high energy density.

Nuclear batteries can provide years of energy, but they do have some drawbacks. For example, they are very expensive to produce and can be harmful if damaged. This latest study will help to reduce the production costs of these devices, which could lead to further innovation and adoption.

Make Other Precious Metals

Today, many metals are far more valuable than gold. Recognizing this fact, the engineers noted that this method of transmutation could also work for the creation of other metals like palladium. However, just like the gold, these newly produced metals will have some nuclear radiation that will need to be slowly lost over their nearly two decades of storage requirements.

Marathon Fusion Study Timeline

Marathon Fusion hopes to get its technology into operations within the next 5 years. The team has proven to be ambitious in their search to find reliable partners. Recently, the scientists met with Bill Gates at the 2024 Breakthrough Energy Summit in London.

Marathon Fusion Study Researchers

Marathon Fusions hosted the scientific research for this study. Specifically, the paper lists a former engineer at SpaceX, Adam Rutkowski, and former Google CEO Eric Schmidt as major contributors. Marathon Fusion is based out of San Francisco, CA. It was founded in 2023 and has secured +$5.9M in funding.

Additionally, the team received grant funds from the US Department of Energy and the Breakthrough Energy Fellows program.

Marathon Fusion Study Future

Now that the simulations have been run, the team seeks to conduct real-world testing of their theory and have their study peer reviewed. From there, the scientist wants to work on creating a two-layer fusion blanket. This dual-layer approach would create an inner and outer blanket. This strategy would enable the engineers to optimize the inner blanket for gold production without hindering energy production.

Investing in the Nuclear Sector

There are many companies in the nuclear fusion market. This technology is seen by many as the best chance for clean and sustainable energy for the world. However, over the last 60 years, nuclear energy has taken a back seat to other sustainable solutions. Despite the changing market, there are some companies that still believe that fusion is the best path forward. Here’s one firm helping to drive innovation and adoption of nuclear power.

Cameco

Cameco (CCJ +0.87%) entered the market in 1988 as a uranium mining and nuclear fuel producer. Notably, it formed after the merger of Saskatchewan Mining Development Corporation and Eldorado Nuclear Limited. Since that time, the company has seen growing success with mines in operation in the USA, Canada, and Kazakhstan. Together, the company produced around +20M pounds of Uranium concentrate annually.

Cameco was listed on the NYSE in 1996 and has remained a strong competitor in the nuclear fuels sector for decades. During its operations, it has made continual acquisitions to expand its capabilities. Specifically, the company acquired Uranerz Exploration, Mining Limited, Uranerz U.S.A., Inc., and Bruce Power. It also purchased a major stake in Global Laser Enrichment.

Today, Cameco offers a wide array of nuclear fuel-related options. The company’s dedication to quality, security, and safety has helped it to become one of the world’s largest uranium producers and nuclear fuel suppliers. Those seeking exposure to these markets should consider doing more research into Cameco stocks, as the company appears to be poised for long-term growth alongside the industry.

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Marathon Fusion Study Conclusion

It is impressive to see that Marathon Fusion may have unlocked the mystery behind thousands of years of alchemical studies. The team has expressed their excitement and believes that the possibility of gold revenue could be a game changer for future fusion development and investors. Due to these factors and many more, you have to salute this team of innovative minds for their hard work and dedication.

Learn about other cool energy developments here.

Studies Referenced:

^{1. Rutkowski, A. (2025). Scalable Chrysopoeia via (n, 2n) Reactions Driven by Deuterium-Tritium Fusion Neutrons. arXiv. https://arxiv.org/abs/2507.13461}