Nuclear Fusion: An Overview of the Patent Landscape

We’ve previously discussed the growing need for alternative energy sources, starting with solar technology and wind technology. In this post, we’ll discuss yet another promising source of energy generation: nuclear fusion.

Nuclear fusion has the potential to provide clean, efficient, and near-limitless energy. Although it’s unlikely that nuclear fusion will be commercially viable in the immediate future, it’s already on the horizon.

But today, the U.S. Department of Energy (DoE) still invests hundreds of millions of dollars per year in fusion research; and earlier this year, DoE also announced $46 million in funding for eight private companies. In other words, the U.S. government is taking nuclear fusion seriously enough to try and accelerate its commercialization timeframe.

So, it’s clear that nuclear fusion is a worthwhile space for innovation because there is funding available and it could yield long-term gains. If you’re also investing in the potential of nuclear fusion, you’ll need to understand the current state of the art in order to identify the strongest IP opportunities for your business.

What is nuclear fusion?

Nuclear fusion occurs when the nuclei of two lighter atoms fuse to form the nucleus of a heavier atom. The total mass of the new atom is lighter than the sum of the masses of the original atoms; the “lost” mass is released as energy.

Nuclear fusion has a high energy output:

• Compared to burning fossil fuels, fusion generates nearly four million times more energy.
• Compared to nuclear fission (used in current nuclear power plants), fusion generates four times more energy per kilogram of fuel, and also produces minimal nuclear waste.

The global patent landscape for nuclear fusion technology

If you’re interested in pursuing IP protection for your business’s innovations in nuclear fusion, it’s important to understand not only the current state of the art, but also the industry’s current patent landscape.

The Japanese firm Nikkei-astamuse recently compiled a nuclear fusion patent ranking, using criteria such as number of patents filed, the feasibility of each innovation, and the patents’ remaining terms. The top four countries were:

1. China
2. United States
3. United Kingdom
4. Japan

There clearly exists worldwide interest in developing nuclear fusion technology. But given the diverse possibilities for innovation, assessing the role of an international IP strategy in your patent portfolio may need to be done on a case-by-case basis.

According to Reddie and Grose, these are the top 10 institutions that have filed patent applications related to nuclear fusion over the last decade:

1. Tokamak Energy (UK): 319
2. Hefei Institutes of Physical Science (China): 184
3. Southwestern Institute of Physics (China): 119
4. General Fusion (Canada): 110
5. TAE Technologies (USA): 103
6. Lockheed Martin (USA): 92
7. Brilliant Light Power (USA): 87
8. Hamamatsu Photonics (Japan): 68
9. Tri Alpha Energy (USA): 65
10. University of California (USA): 64

From this list, we can see that the institutions investing in nuclear fusion are a mix of public research facilities and privately held companies.

Notably, a majority of these top-ranked institutions hold patents related specifically to reactor design. But based on the industry developments we discuss below, it’s likely that the patent landscape will evolve significantly over the next few decades.

State of the art: Recent and ongoing developments in nuclear fusion

Currently, researchers have been working to develop a reactor that can efficiently harness the energy released from nuclear fusion. At commercial scales, this energy could be nearly limitless.

While we are still many years away from commercializing nuclear fusion, two key types of fusion have risen to the forefront: plasma fusion and inertial confinement fusion.

Plasma fusion

In a plasma fusion reaction, sustained and ongoing fusion is achieved via burning plasmas. (A burning plasma is one where the plasma’s main source of heating comes from the fusion reactions themselves.)

Today, much of the R&D around plasma fusion is centered around developing and constructing tokamaks (which are magnetic fusion devices). In theory, a tokamak could be run on a self-sustaining cycle, where the energy from fusion is used to create more energy. However, one main challenge facing tokamaks is sustaining the intense heat levels necessary for fusion to occur.

A prominent example of plasma fusion can be found in the ITER project — an international collaboration between 35 nations to build the world’s largest operational tokamak. 

At Henry Patent Law Firm, our team boasts a strong background in fusion and plasma physics. During my time as a graduate student at MIT, plasma fusion was one of the main subjects of ongoing research in our department.

Inertial confinement fusion

In an inertial confinement fusion process, small quantities of fusion fuel are compressed and heated until the resultant pressure causes the fuel to undergo a nuclear fusion reaction.

While there are several ways to trigger inertial confinement fusion, the industry is currently focused on using lasers, as exemplified by a recent breakthrough at the National Ignition Facility (NIF) in California.

Laser fusion: NIF’s methodology

In December 2022, NIF experienced one of the most promising recent breakthroughs in nuclear fusion: It became the first to achieve ignition (where more energy is generated from a controlled nuclear fusion reaction than the energy used to trigger it).

To get this result, NIF heated its fuel using an indirect-drive approach. It focused 192 lasers onto a hohlraum (a gold cylinder) containing the hydrogen isotopes deuterium and tritium. Heating the hohlraum generated X-rays that crushed the fuel pellets.

This process, which cost 2.05 megajoules of energy, released 3.15 megajoules of energy — a 54% increase. Incidentally, this also topped the previous record for energy generation, which was just 1.3 megajoules.

As groundbreaking as this development was, the experiment itself remains flawed due to imperfections in the laser technology:

• Inefficient: Firing up the 192 lasers alone took 322 megajoules of energy.
• Inconsistent: Subsequent attempts to repeat the experiment in 2023 have produced a wide range of results, from 1.6-3.88 megajoules.

In any case, NIF’s pioneering work to achieve ignition is a critical stepping stone towards commercializing nuclear fusion.

Laser fusion: Other methodologies

Obviously, NIF is far from the only institution innovating around laser fusion. The technology being developed by other institutions tends to differ from NIF’s in three key areas: heating methods, laser construction, or laser fuel.

1. Heating methods

NIF’s indirect-drive approach heats the fuel pellet indirectly by generating X-rays. The alternative is direct-drive fusion, which heats the fuel pellet directly. In theory, this should transfer more of the laser’s heat to the target, therefore increasing its efficiency.

Some of the institutions innovating with direct-drive fusion include:

• Naval Research Laboratory (Washington, DC): Researching argon fluoride (ArF) laser fusion
  • In ArF, argon and fluoride gases are used to produce ultraviolet light.
  • The laboratory has found that ArF’s ultraviolet light could enable a higher fusion energy gain over that of the energy needed to power the laser.
• Laboratory for Laser Energetics (University of Rochester in Brighton, NY): Using their 60-beam Omega laser system to conduct nuclear fusion research

2. Laser construction

Laser technology generally faces a key conundrum: Large equipment cannot continuously operate lasers, while small equipment cannot generate enough heat to ignite the fuel.

The size of NIF’s equipment is contributing to its inefficiency, as its lasers can be fired only about ten times per week. Additionally, it is converting only about 1% of electricity pulled from the grid into laser light.

To address this conundrum, some companies are exploring using diodes to power their lasers. Examples of these companies include:

• Longview Fusion Energy Systems (Orinda, CA)
• Blue Laser Fusion (Palo Alto, CA)

Alternatively, companies like Focused Energy (Darmstadt, Germany and Austin, TX) are using fast ignition to trigger the fusion reaction. Fast ignition involves using two separate lasers, instead of one: the first laser compresses the fuel and then, once the fuel reaches maximum density, the second laser ignites the burn.

3. Laser fuel

Fusion developers like NIF commonly use deuterium and tritium to fuel nuclear fusion, because deuterium-tritium reactions promise the highest energy output at the lowest temperatures.

But deuterium-tritium reactions also have their drawbacks. For one, tritium is rarely found naturally; it also has a half-life of only 12 years. For another, deuterium-tritium reactions produce fast-moving neutrons that can weaken the equipment’s structure, and turn it slightly radioactive.

Many companies are exploring using different isotope pairings to achieve fusion, including:

• Xcimer Energy (Redwood City, CA): Using krypton and fluorine, as their excimer laser technology requires them to use high-pressure gas
• HB11 Energy (Sydney, Australia): Fusing hydrogen and boron-11
• Marvel Fusion (Munich, Germany): Mixing hydrogen and boron with deuterium and tritium, with the goal of chemically enabling the fuel to be solid at room temperature

Achieving inertial confinement fusion without lasers

While NIF’s success has shown promise for using laser technology to achieve inertial confinement fusion, there are also other methods of compressing and heating the fusion fuel.

For example, First Light Fusion (Oxford, UK) is developing ways to fire a high-speed projectile at the fuel pellet instead.

The importance of partnering with a qualified patent attorney

Nuclear fusion technology is technically complex and fast-changing. If you’ve decided that pursuing patent protection is the right next step for your business, we highly recommend partnering with a subject matter expert in order to craft an appropriate IP strategy for your needs.

The team at Henry Patent Law Firm is well-qualified to handle patent filings related to nuclear fusion. My research background is in quantum physics, and I earned my Ph.D. in MIT’s Department of Nuclear Science and Engineering.

Ready to get started? Let us know how we can help.