Sparc nearing completion: CFS integrates revolutionary magnets and strengthens the strategic partnership with Nvidia

The Number One Magnet Takes Action: CFS Project Accelerates Toward 2027

During CES 2026, Commonwealth Fusion Systems announced a major technical milestone: the inaugural placement of one of the 18 magnets destined for its experimental Sparc reactor. This component represents the first piece of a complex toroidal structure that, once completed, will generate and sustain an ultra-strong magnetic field for plasma confinement. The company plans to complete the assembly of the entire magnet array by the end of summer, with reactor activation scheduled for the following months.

The fusion energy landscape is undergoing a tangible transformation. After decades of unfulfilled promises, the timelines are finally shortening, and CFS is openly competing with other industry players to be among the first to deliver fusion-generated electricity to the grid. Major industrial players have set their goals for the early 2030s, when the technology could provide a virtually inexhaustible energy source with very low emissions, replicating the infrastructure of conventional power plants.

Magnet Technical Specifications: Extraordinary Capacity and Cryogenic Challenges

Each magnet destined for Sparc is a sophisticated engineering feat. It weighs about 24 tons and can generate a magnetic field of 20 tesla—an power equivalent to approximately 13 times that of MRI devices used in hospitals. “The strength generated by these magnets is enough to lift an entire aircraft carrier,” emphasized Bob Mumgaard, co-founder and CEO of CFS.

To achieve such magnetic intensities, the magnets require cooling down to -253°C, an extremely low temperature that allows them to carry currents exceeding 30,000 amperes without significant losses. Once mounted vertically on the cryogenic stainless steel structure with a diameter of 24 feet and weighing 75 tons (installed in March 2025), the system will be ready to contain the superheated plasma. The internal temperature of the plasma will surpass 100 million degrees Celsius, creating the conditions for fusion reactions.

Digital Synergy: CFS, Nvidia, and Siemens Build the Virtual Twin

A distinctive element of CFS’s development strategy is the strategic collaboration with Nvidia and Siemens to create an integrated digital twin of the Sparc reactor. Siemens brings its expertise in design and manufacturing software, providing tools to acquire and standardize operational data. Nvidia, for its part, offers the Omniverse platform, an advanced virtual environment where the digital model of the reactor can evolve and interact in real time.

So far, CFS has conducted isolated simulations on individual Sparc components, obtaining reliable predictions on partial performance. The new digital twin ecosystem represents a qualitative leap: it allows continuous and simultaneous comparison between the behavior of the virtual model and that of the physical reactor. “Instead of launching separate simulations, we will be able to monitor the digital twin in parallel with Sparc throughout the entire operational cycle,” Mumgaard explained. This approach enables the team to virtually test modifications and parameters before implementing them in the real system, significantly shortening development cycles and reducing risks.

The Financial Path to Arc: 3 Billion and the Commercial Vision

The development of Sparc has represented a colossal investment. Commonwealth Fusion Systems has so far mobilized nearly $3 billion in capital, including the $863 million raised in the Series B2 phase last August, during which Nvidia and Google actively participated as major investors. These funding flows reflect the growing market confidence in the tangible possibilities of controlled nuclear fusion.

Looking beyond Sparc, CFS is already planning Arc, its first commercial fusion power plant. This facility will be a global benchmark for the sector, with budgets expected to be in the billions of dollars. Mumgaard is convinced that technological acceleration in digital twins and artificial intelligence will be a critical enabling factor to shorten commercialization timelines. “As machine learning algorithms refine and our digital models gain increasing accuracy, we will be able to move even faster—a vital necessity given the urgency of the global energy transition,” he stated.