Decades of global, government-sponsored research in fusion science have established the tokamak-based reactor as the highest performing approach to fusion. In the past, tokamaks have had to be enormous in size to produce net energy from fusion. Commonwealth Fusion Systems (CFS) is using revolutionary superconducting magnets developed in collaboration with MIT to construct smaller and lower-cost tokamak fusion systems.
     CFS is currently developing a tokamak device called SPARC. The company is working to demonstrate the critical fusion energy milestone of producing more output power than input power for the first time in a device that can scale up to commercial power plant size. However, this achievement will only be possible if the plasma doesn’t melt the device.
     Researchers from CFS and Oak Ridge National Laboratory (ORNL) have collaborated on fusion boundary research through a series of projects. These projects include ORNL Strategic Partnership Projects and Laboratory Directed Research and Development projects, work under the Innovation Network for Fusion Energy (INFUSE) program, and other work in partnership with General Atomics.
     Throughout this collaboration, ORNL has developed the simulation capabilities that are necessary to address critical and time-sensitive design issues for the SPARC tokamak.
     The study was published in Nuclear Fusion. It evaluated actuator configurations, in particular those used to control neutral gas flowing in and out of the tokamak.
     A power-producing fusion plasma reactor must reach a temperature at its center hotter than the core of the Sun. At the same time, it must maintain a temperature at the edge of the plasma that is cool enough to avoid vaporizing the fusion device.
     New studies have found that using louvers at the bottom of the fusion device create local conditions that can reduce the temperature of the edge plasma. The louvers permit the hot plasma to “detach” from the walls of the device, spreading out the heat.
     In order to predict the actuators’ ability to control the plasma, ORNL developed new methods to execute a major simulation code, SOLPS-ITER, in a dynamic, time-dependent manner, focused on the actuator design.
     The SOLPS-ITER code models plasma and neutral transport in the boundary region of fusion devices. It has been used to design plasma-facing components for many tokamaks, including the multinational ITER device under construction in France.
     This new dynamic simulation goes beyond standard steady-state models and was developed in a staged manner. First, it considered only plasma transport for predictive control. Next, the response of neutral particles to louver actuators was added. Finally, a fully coupled dynamic model was developed.
     The CFS team used this information from their simulation to zero in on the simplest and least expensive actuator and diagnostics options from a large number of options. This effort enables fusion energy scientists to better control tokamak devices.
     The results of this study indicate a new path for handling this extreme heat, bringing researchers one step closer to a commercial fusion energy source. The study utilized a new simulation capability that accelerates work on whole-device modeling and helps inform researchers about the systems that will control the SPARC plasma.
In addition to the SPARC tokamak project, CFS is working on its successor, the ARC power plant, to supply power to the electric grid.

Commonwealth Fusion Systems 

     Heating plasma to the ultra-high temperatures needed for fusion reactions new techniques. Researchers have considered multiple methods, one of which involves injecting electromagnetic heating waves into the plasma. This is basically the same process that heats food in microwave ovens. However, when they produce one type of heating wave, they can sometimes simultaneously create another type of wave that does not heat the plasma. This is a waste of energy.
     To solve this problem, scientists at the U.S. Department of Energy’s (DoE) Princeton Plasma Physics Laboratory (PPPL) have performed computer simulations. They have developed a new technique that prevents the production of the unhelpful waves, known as slow modes. This boosts the heat put into the plasma and increases the efficiency of the fusion reactions.
     Eun-Hwa Kim is a PPPL principal research physicist and lead author of the paper reporting the results in Physics of Plasmas. He said, “This is the first time scientists have used 2D computer simulations to explore how to reduce slow modes. The results could lead to more efficient plasma heating and possibly an easier path to fusion energy.”
     The team included researchers from General Atomics who use the DIII-D tokamak fusion facility. They determined that positioning a metal grate known as a Faraday screen at a slight five-degree slant with respect to the antenna producing the heating waves (which are also known as helicon waves) stops the production of the slow modes. Researchers want to avoid creating slow modes because they cannot penetrate the magnetic field lines confining the plasma to heat the core. This is where most fusion reactions occur. In addition, the slow modes are easily damped or cancelled out by the plasma itself. Any energy used to create slow modes is energy that is not used to heat the plasma and foster fusion reactions.
     The researchers simulated the production of helicon waves and slow modes using the Petra-M computer code. This is a powerful and versatile program used to model electromagnetic waves in fusion devices and space plasmas. The simulations replicated conditions in the DIII-D tokamak which is a doughnut-shaped plasma device operated by General Atomics for the DoE.
     The team carried out a series of virtual experiments to test which of the following methods had the greatest effect on the production of slow modes: the antenna’s alignment, the Faraday screen’s alignment or the density of electrons in front of the antenna. The simulations confirmed that when the Faraday screen was aligned at an angle of five degrees or less from the orientation of the antenna, the screen, in effect, short-circuits the slow modes, making them dissipate before they propagate into the plasma. The suppression of the slow modes depends mainly on how much the Faraday screen leans to the side.
    Masayuki Ono is a PPPL Principal Research Physicist and one of the paper’s authors. He said, “We found that when the screen’s orientation exceeds five degrees by only a little bit, the slow modes grow by a great deal. We were surprised by how sensitive the development of slow modes was to the screen alignment.” Scientists will be able to use this information to refine the design of new fusion facilities to make their heating more powerful and efficient.
     In the future, the scientists plan to improve their understanding of how to prevent slow modes by running computer simulations that consider more of the plasma’s properties and factor in more information about the antenna.

General Atomics

Part 3 of 3 Parts (Please read Parts 1 and 2 first)
     Sid Pathak is an assistant professor at Iowa State. He is leading the team that will test the material samples for the second layer. When the material powder made by the Ames Lab group is ready, it will be formed into plates at PNNL by spraying the powder onto a surface.
     Pathak said, “Once you make that plate, we need to test its properties, particularly its response under the extreme radiation conditions present in a fusion reactor, and make sure that we get something better than what is currently available. That’s our claim, that our materials will be superior to what is used today.”
     Pathak explained that it can take ten to twenty years for radiation damage to appear on materials in a nuclear reactor. It would be impossible to recreate that timeline during a three-year research project. Instead, his team utilizes irradiation to see how materials respond in extreme environments. His team will use a particle accelerator to attack a material with ions available at University of Michigan’s Michigan Ion Beam Laboratory. The results will simulate how the material is affected by radiation.
     Pathak said, “Ion irradiation is a technique where you radiate [the material] with ions instead of neutrons. That can be done in a matter of hours. Also, the material does not become radioactive after ion irradiation, so you can handle it much more easily.”
     There is one disadvantage to the use of ion irradiation. The damage caused by the ions only penetrates the material one or two micrometers deep. This means that it can only be seen with a microscope. Testing materials at these very small depths requires specialized tools that work at micro-length scales such as those which are available at Pathak’s lab at Iowa State University.
     Tiarks said, “The pathway to commercial nuclear fusion power has some of the greatest technical challenges of our day but also has the potential for one of the greatest payoffs—harnessing the power of the sun to produce abundant, clean energy. It’s incredibly exciting to be able to have a tiny role in solving that greater problem.”
     Argibay commented that “I’m very excited at the prospect that we are kind of in uncharted water. So there is an opportunity for Ames to demonstrate why we’re here, why we should continue to fund and increase funding for national labs like ours, and why we are going to tackle some things that most companies and other national labs just can’t or aren’t. We hope to be part of this next generation of solving fusion energy for the grid.”
     Extreme levels of temperature and pressure are required for the creation of nuclear fusion on the surface of the Earth. This means that new materials must be developed and tested to withstand these extreme conditions before commercial nuclear fusion will be possible. The prospects are bright for the development of commercial nuclear fusion but there are many technical challenges that must be solved before fusion energy will be available at grid scale.

Pacific Northwest National Laboratory

Part 2 of 3 Parts (Please read Part 1 first)
     Jordan Tiarks is another scientist at Ames Lab who is working on the project led by PNNL. He is focused on a different aspect of this reactor research. His team is relying on Ames Lab’s thirty-five years of experience leading the field in gas atomization, powder metallurgy, and technology transfer to industry to develop materials for the first wall structural material in a fusion reactor.
     Tiarks said, “The first wall structural material is the part that holds it all together. It requires more complexity and more structural strength. Things like cooling channels need to be integrated in the structural wall so that we can extract all of that heat, and don’t just melt the first wall material.”
     Tiarks’s team hopes to utilize over a decade of research focused on developing a unique way of creating oxide dispersion strengthened (ODS) steel for next generation nuclear fission reactors. ODS steel contains very small ceramic particles (nanoparticles) that are distributed throughout the steel. These particles improve the metal’s mechanical properties and assist in the ability to withstand high irradiation.
     Tiarks said, “What this project does is it takes all of our lessons learned on steels, and we’re going to apply them to a brand-new medium, a vanadium-based alloy that is well suited for nuclear fusion.”
     The major challenge that Tiarks’s team now faces is how vanadium behaves differently from steel. Vanadium has a much higher melting point, and it is more reactive than steel. It cannot be contained with ceramic. Instead, his team must use a similar but different process for creating vanadium-based powders.
     Tiarks explained, “We use high pressure gas to break up the molten material into tiny droplets which rapidly cool to create the powders we’re working with. And [in this case] we can’t use any sort of ceramic to be able to deliver the melt. So what we have to do is called ‘free fall gas atomization’. It is essentially a big opening in a gas die where a liquid stream pours through, and we use supersonic gas jets to attack that liquid stream.”
     There are some significant challenges with the method Tiarks described. The first problem is that it is less efficient than other methods that rely on ceramics. The second problem is that due to the high melting point of vanadium, it is harder to add more heat during the pouring process. This would provide more time to break up the liquid into droplets. The third problem is that vanadium tends to be reactive.
     Tiarks added that “Powders are reactive. If you aerosolize them, they will explode. However, a fair number of metals will form a thin oxide shell on the outside layer that can help ‘passivate’ them from further reactions. It’s kind of like an M&M. It’s the candy coating on the outside that protects the rest of the powder particle from further oxidizing.”
     Tiarks continued that, “A lot of the research we’ve done in the Ames lab is actually figuring out how we passivate these powders so you can handle them safely, so they won’t further react, but without degrading too much of the performance of those powders by adding too much oxygen. If you oxidize them fully, all of a sudden, now we have a ceramic particle, and it’s not a metal anymore, and so we have to be very careful to control the passivation process.”
     Tiarks went on to explain that discovering a powder processing method for vanadium-based materials should make them easier to form into the complicated geometric shapes that are necessary for the second layer to function properly. In addition, vanadium will not interfere with the powerful magnetic fields in the reactor core.
Please read Part 3 next

Iowa State University

Part 1 of 3 Parts
     Researchers at the U. S. Department of Energy (DoE) Ames National Laboratory and Iowa State University are leading efforts to overcome material challenges to making commercial fusion a reality. The research teams are part of a DoE Advanced Research Projects Agency-Energy (ARPA-E) program referred to as “Creating Hardened And Durable fusion first Wall Incorporating Centralized Knowledge” (CHADWICK). They will research materials for the first wall of a fusion reactor. The first wall is the part of the reactor that surrounds the fusion reaction. It bears the brunt of the extreme heat and pressure in the fusion reactor core.
     ARPA-E recently selected thirteen projects under the CHADWICK program. Of those thirteen, Ames Lab leads one of the projects. It is also collaborating with Iowa State on another project, which is led by Pacific Northwest National Laboratory (PNNL).
     Nicolas Argibay is a scientist at the Ames Lab and the lead of one project. One of his key challenges in harnessing fusion-based power is containing the plasma core that generates the energy. The plasma is like a miniature sun that needs to be contained by materials that can survive a combination of extreme temperature, extreme pressure, irradiation, and magnetic fields while efficiently extracting heat for conversion to electricity.
     Argibay explained that in the reactor core, the plasma is contained by a strong magnetic field, and the first wall surrounds this environment. The first wall has two layers of material. One layer is closest to the strong magnetic and plasma environments. The other layer will help move the energy along to other parts of the system.
     The first layer material needs to be structurally sound, and able to resist cracking and erosion over time. Argibay also said that it cannot stay radioactive for very long because the reactor needs to be turned on and off for maintenance without endangering anyone working on it. The project that Argibay is leading is focused on the first layer material.
     Argibay said, “I think one of the things we [at Ames Lab] bring is a unique capability for materials design, but also, very importantly, for processing them. It is hard to make and manage these materials. On the project I’m leading, we’re using tungsten as a major constituent, and with the exception of some forms of carbon, like diamond, that’s the highest melting temperature element on the periodic table.”
     Special equipment is required to process and test refractory materials, which have extremely high melting temperatures. In Argibay’s lab, the first piece of equipment installed was a commercial, modular, customizable, open-architecture platform for making refractory materials. The lab will explore advanced and smart manufacturing methods to make the process more efficient and reliable.
     Argibay added, “Basically, we can make castings and powders of alloys up to and including pure tungsten, which is the highest melting temperature element other than diamond.”
     By spring of 2025, Argibay said that they intend to have two additional systems in place for creating these refractory materials at both lab-scale and pilot-scale quantities. He explained it is easier to make small quantities (lab-scale) than larger quantities (pilot-scale). However, larger quantities are important for collecting meaningful and useful data that can translate into a real-world application.
     Argibay’s team also has the ability to examine the mechanical properties of refractory materials at relevant temperatures. Systems able to make measurements well above eighteen hundred degrees Fahrenheit are rare. Ames Lab has one of the only commercial thermal testers in the country that can measure tensile properties of alloys at temperatures up to twenty-seven hundred degrees Fahrenheit. This puts the lab in a unique position to support process science and alloy design.
Please read Part 2 next

Ames National Laboratory

     A research team has just clarified the process behind the generation of runaway electrons during the startup phase of a tokamak fusion reactor. The paper is titled Binary Nature of Collisions Facilitates Runaway Electron Generation in Weakly Ionized Plasmas. It was published in the journal Physical Review Letters.
     Nuclear fusion energy refers to a power generation method that harnesses the energy of a process that attempts to replicate the fusion process that powers our sun and other stars, using resources extracted from seawater. To achieve this, technology capable of confining high-temperature plasma exceeding 100 million degrees Celsius under extreme pressure for extended periods in a fusion reactor is essential.
     A tokamak is an artificial sun system in the shape of a torus, with no beginning or end, where magnetic fields are applied to confine particles.
     To initiate nuclear fusion reactions within a tokamak, high-temperature plasma must first be generated, a process known as “startup.” The startup process requires a strong electric field, similar to the principle of lightning, but this electric field also leads to the generation of “runaway electrons.”
     Runaway electrons are high-energy electrons that receive continuous acceleration from the electric field, becoming so fast that their acceleration is unstoppable. These electrons hinder plasma formation by taking it off externally applied energy and can damage the device, making them one of the critical challenges that must be resolved for successful nuclear fusion.
     Therefore, accurately predicting the formation of runaway electrons is essential for the commercialization of tokamak reactors.
     Runaway electron generation rate as a function of ionization degree. Credit: Seoul National University College of Engineering
     Through collaborative research with the Max-Planck Institute for Plasmaphysik and ITER (International Thermonuclear Experimental Reactor) International Organization, Seoul National University’s Professor Yong-su Na (corresponding author) and Ph. D. student Lee (first author) discovered that existing theories fail to adequately explain this phenomenon.
     They generalized a kinetic theory to identify a novel mechanism for the generation of runaway electrons, addressing a theoretical bottleneck in the design of start-up processes for ITER and commercial fusion reactors.
     The research team found that the formation of runaway electrons during startup has a binary nature, determined by whether inelastic interactions with individual neutral particles occur. Electrons that avoid inelastic interactions with neutral particles significantly contribute to the formation of runaway electrons.
     To elucidate this, they generalized the theory of electron kinetics and demonstrated the mechanism that classical theory failed to capture.
     The results of this study are expected to be applied not only to the startup design of Korea’s demonstration and commercial reactors but also to ITER, a collaborative project involving South Korea, the European Union, the United States, Japan, Russia, China, and India.

National University of Seoul

     The globe’s first-ever grid-scale commercial nuclear fusion power plant is coming to Chesterfield County.

     In a December 17th press release, Commonwealth Fusion Systems (CFS) announced that a plant powered by nuclear fusion called “ARC” will provide four hundred megawatts of power to Virginia’s energy grid — or enough to power about 150,000 homes — starting in the early 2030s. It will be constructed in the one hundred acres James River Industrial Park.
     This development was made possible through an agreement with Dominion Energy. According to the press release, through this “nonfinancial collaboration,” Dominion will provide CFS with development and technical expertise. It will provide leasing rights for the site, which it currently owns.
     A spokesperson for Dominion Energy said in the press release that its customers’ “growing needs for reliable, carbon-free power [benefit] from as diverse a menu of power generation options as possible.”
     Nuclear fusion is a process where two light atomic nuclei combine, forming a single heavier one and releasing “massive amounts of energy,” according to the International Atomic Energy Agency (IAEA).
     CFS said in the press release, “Fusion is the last energy source humanity needs, with cheap and abundant fuel, inherently safe operations, and no greenhouse gas emissions. Now ARC has a place to happen.”
    This fusion power plant’s development depends on the work being done by CFS on “SPARC” which is a tokamak machine that demonstrates the production of fusion energy. According to the press release, SPARC is expected to produce its first plasma in 2026. Then net fusion energy should follow soon after, “demonstrating for the first time a commercially relevant design that will produce more power than consumed.” Once that is completed, ARC can become a reality.
     The company said that, in addition to generating clean energy, ARC will also create hundreds of jobs for Virginians. The state’s workforce encouraged CFS to pick the James River Industrial Park as the location for the fusion reactor, according to the press release.
     CFS said, “We selected this site because it has all the things one would want for the site for the first commercial fusion power plant. It’s in a state and county that has welcomed us. It can put the power to good use. It has a workforce that is capable and eager. The physical site is big enough, flat enough and near good transportation. It has a connection to the grid after a coal power plant retired. And it’s accessible so the world can come and visit.”

     In a December 17th press release from the Office of the Governor, Governor Glenn Youngkin praised CFS’ choice to develop in Virginia as a “historic moment.”
     Youngkin said. “Commonwealth Fusion Systems is not just building a facility, they are pioneering groundbreaking innovation to generate clean, reliable, safe power, and it’s happening right here in Virginia. We are proud to be home to this pursuit to change the future of energy and power.” The Governor’s office added that this plant is expected to generate billions of dollars in economic development.

Commonwealth Fusion Systems

     Two U.K. public sector entities – the U.K. Atomic Energy Authority (UKAEA) and the Science and Technology Facilities Council’s Hartree Centre (STF) – are collaborating with US-headquartered technology firm IBM to design future experimental fusion power plants.
     The partnership intends to unite fusion scientists and Artificial Intelligence (AI) experts from the three organizations to achieve transformative breakthroughs in applying AI to fusion power plant designs and experimental facility operations. The collaboration will combine the Hartree Centre and IBM’s expertise in AI and high-performance computing, with UKAEA’s data and modelling capabilities. They will create a ‘frontier’ or ‘foundation model’ capable of learning and underpinning the fundamental dynamics of experimental fusion data. The UKAEA is the U.K.’s national organization responsible for researching and delivering fusion energy. It will provide program requirements, domain expertise and selected data from its JET and MAST-U machines.
     IBM said, “Our approach to-date for designing these complex machines has been one of ‘test-based design’ – ie an iterative approach of ‘learning by doing’. Unfortunately, measured against the demanding timeline for decarbonizing and transitioning economies into the Net-Zero era, test-based design for fusion has now become too slow and too expensive.”

     IBM added, “It is essential therefore that the fusion sector adopts the latest digital technologies to accelerate and de-risk the delivery of commercial fusion power – for operations and for plant design. In short, we must move the dial which represents how we design complex strongly coupled fusion systems away from test-based design and towards the digital world of simulation and ‘data centric’ engineering.”
     The new collaboration is expected to develop foundation models that can learn the underpinning dynamics of the UKAEA’s fusion plasma/plant experimental data. This will allow the generation of new information and new capabilities that will feed into various applications, including training downstream models for simulation and/or prediction. Utilizing these techniques, the models will ‘learn’ from past experiments. Ideally, these models will evolve ‘incrementally’ whereby they will ingest live experimental data.
     Rob Akers is the UKAEA Director of Computing Programs. He said, “I am delighted that we are joining forces with IBM and STFC’s Hartree Centre to work on our ambitious program aiming to deliver commercial fusion in the 2040s by exploiting the transformative power of Artificial Intelligence. IBM’s expertise in complex systems engineering and supercomputing and the Hartree Centre’s expertise in democratizing high-performance computing and AI into the engineering sector, combined with UKAEA’s leading research and development in fusion energy will be a powerful force for progress in this hugely important field.”
     Vassil Alexandrov is the Chief Science Officer at national computing center, STFC Hartree Centre. He said, “I am really very pleased that, thanks to our well-established collaborations with both IBM and UKAEA, we can now come together to address a key grand challenge and advance state-of-the-art in modelling and simulation of fusion powerplants, thereby supporting the UK’s ambition to become a global leader in clean energy innovation.”
     Juan Bernabe-Moreno is the Director of IBM Research Europe, U.K. and Ireland. He commented, “I am especially excited to see our team exploring together with the UKAEA and the Hartree Centre experts how we can use generative AI technologies to approach one of the most challenging problems of our time. It is certainly a testament to the kind of research we are driving in the UK for the greater good.”

Hartree Centre

     The preliminary design of Russia’s proposed tokamak with reactor technologies (TRT) nuclear fusion reactor has been completed by JSC NIIEFA which is the primary nuclear fusion research organization in Russia.
     The project is part of the federal KP RTTN project to develop technologies for controlled nuclear fusion and innovative plasma technologies. It is being carried out by specialists at JSC NIIEFA for Rosatom’s Department of Scientific and Technical Programs and Projects,
     Rosatom describes the TRT as a “tokamak with a long discharge pulse, a strong magnetic field and an electromagnetic system made of a high-temperature superconductor … the construction of the TRT is an important stage in the development of controlled thermonuclear fusion and the creation of a nuclear power reactor in Russia – an environmentally friendly source of energy with virtually inexhaustible fuel resources”.
     The draft design details the fundamental design solutions and a general idea of the structure, dimensions and operating principles for the TRT as well as the technical requirements for the external systems of the tokamak including the power supply, cryogenic cooling, water cooling, vacuum pumping and maintaining operating pressure. The TRT is intended to play a key role in Russia’s plan to develop future nuclear fusion and/or fusion-fission hybrid power reactors.
     Alexey Konstantinov is Deputy Director and Chief Designer of NTC Sintez. He said, “The preliminary design of a tokamak with reactor technologies developed at JSC NIIEFA is a major milestone … acceptance of the preliminary design marks the start of further work on the creation of the TRT both at JSC NIIEFA and at other research centers, institutes, and enterprises … the results of the work performed provide the opportunity to move on to the next stage – the development of the technical design of the TRT.”
     Sergey Gertsog is the Director General of NIIEFA. He said, “The implementation of such a project will provide a virtually unlimited source of clean and safe energy and significantly reduce dependence on fossil fuels, as well as reduce greenhouse gas emissions. Possession of such technologies will raise the country to a new level of technological development and attract investment in research and development, which will contribute to the development of related industries, such as materials science, cryogenic technology and supercomputers, and the creation of new jobs.”
     The preliminary design work for the TRT started in 2022 and depends, among other things, on experience and knowledge gained from the multinational ITER project to build a fusion plant in southern France. Rosatom comments that “at the same time, a large number of new technologies that do not exist anywhere else in the world will be tested for the first time at TRT”. A published concept paper describes the project as being “developed to facilitate fast and economically sound transition to the pure fusion reactor as well as to the fusion neutron source for the hybrid fusion-fission system”. The goal is to build the TRT by 2030.

Rosatom
 

      As global energy rises, both public institutions and private companies have increased their efforts toward nuclear fusion. Acceleron Fusion is a start-up working on muon-catalyzed fusion energy. The fusion energy firm has recently secured twenty-four million dollars in funding to develop a revolutionary approach to clean energy production. The funding follows a major technical milestone that was achieved by Acceleron in October.
     The company successfully operated its experimental fusion reactor with highly compressed deuterium-tritium (DT) fuel for twenty-eight continuous hours, following over one hundred hours of testing with deuterium. This achievement signals significant progress toward demonstrating the viability of muon-catalyzed fusion as a clean and abundant energy source.
     Acceleron Fusion is working on a radically different reactor design from many other companies working on fusion energy. The company is not using the extremely high temperatures that are common in fusion experiments. Instead, Acceleron is working on a method that uses much lower temperatures. Their new method utilizes particles called muons.
     Muons are similar to electrons, but they are about two hundred times heavier. They are produced when protons and neutrons collide. This creates particles called pions which then decay into muons. Muons can be generated artificially by firing an ion beam from a particle accelerator into a target which is typically made of carbon or some metal.
     When a beam of muons is directed at a highly compressed pellet of deuterium and tritium, the muons facilitate fusion reactions at temperatures much lower than those required in traditional fusion reactors.
     Traditional fusion approaches, such as magnetic confinement and inertial confinement, require enormous heat to create plasma. This plasma must then be contained and compressed with powerful magnets or lasers, which are complex and energy-intensive.
     Acceleron’s technology bypasses these requirements by operating below one thousand eight hundred and thirty-two degrees Fahrenheit.  Operating at this cooler temperature potentially offers significant advantages in efficiency and safety.
     According to a company in a press release, “Traditional fusion machines require extreme temperatures of one hundred and eighty million degrees Fahrenheit. Acceleron’s technology uses muons to achieve fusion reactions at temperatures below two thousand degrees Fahrenheit.”
     However, muon-catalyzed fusion presents a number of unique challenges. Particle accelerators which are used to generate muons, consume a lot of energy.
     The company added that “In the mid-1980s, several groups worldwide demonstrated more than one hundred fusion reactions per muon, raising the possibility that the process could be used to generate energy. However, calculations done at the time concluded that it would take more energy to power the muon source than could be released by the fusion.”
     In order to achieve net energy gain, each muon must catalyze many fusion reactions. Furthermore, muons are short-lived, and they decay in just two and two tenths microseconds. About one percent of the time, they stick to other particles produced during fusion and become unusable.
     The press release added that “Acceleron is developing an intense, high-efficiency muon source to produce beams of muons using significantly less energy than current facilities, and a high-density fusion cell to allow each of these muons to catalyze larger numbers of fusion reactions.”
     To increase the number of fusion reactions per muon, Acceleron compresses the fuel in a diamond anvil to pressures between ten thousand and one hundred thousand pounds per square inch. This is far beyond the pressures that they used in previous experiments.
     Acceleron Fusion is not the only company working on nuclear fusion energy research. A number of other companies across the world have been testing several different approaches, including magnetic confinement fusion, inertial confinement fusion, and even other variations of muon-catalyzed fusion. However, according to experts, it might take many more years before fusion power becomes a reliable source of energy.

Acceleron