Cambridge Heavy Industries Raises $6.2 Million for Compact Fusion Reactor

Cambridge Heavy Industries has raised $6.2 million in seed funding to construct its first compact fusion reactor at its Massachusetts facility. The round, led by Azolla Ventures, closed as the company emerged from stealth with a prototype the size of two dinner tables that has already reached pressures of 350 gigapascals.

The company, launched in 2025 as a spinout of the Massachusetts Institute of Technology, builds compact, laser-based fusion systems designed to produce tritium and other rare isotopes. Its four co-founders are CEO Dr. Yun Kai, Raffi Freeman, Professor Keith Nelson, and Dr. Steve Kooi. Unlike conventional fusion developers that rely on bespoke, capital-intensive laser installations, CHI uses commercially available lasers and modular, benchtop-scale hardware.

The immediate commercial target is tritium, a rare radioactive isotope of hydrogen that fuels fusion research reactors. According to the company, tritium faces significant global supply shortages and currently sells for approximately $33 million per kilogram. CHI also sees downstream applications for its neutron sources in material defect engineering and neutron imaging.

How fast is the development cycle?

The company claims its approach compresses fusion R&D timelines from years to weeks. CHI said its systems allow for weekly testing and upgrades, compared with the years-long development cycles of conventional fusion systems. Advances in shockwave science enable compression efficiency 400 times higher than previous laser-based fusion approaches, at a fraction of the capital expenditure.

The prototype has achieved pressures of 350 gigapascals using only tens of millijoules of energy. Matthew Nordan, co-founder and General Partner at Azolla Ventures, framed the bet as an industrialization play rather than a pure science play. He said: "Cambridge Heavy Industries' technology can be demonstrated on a benchtop and assembled in days using standard optical components. The same rapid test/fail/fix model is what brought us modern space and defense technologies; we see it as a promising approach to make fusion viable."

What does this change for the fusion supply chain?

Dr. Yun Kai positioned the company as an answer to a materials bottleneck that sits upstream of every fusion power program. He said: "Fusion power leaders have a tritium supply problem that could significantly slow down the sector's growth. Our technology is in the unique position to solve this challenge. We are appreciative of our investors for their financial and operational support in bringing us to this important milestone."

The near-term revenue model, then, is isotope production for a constrained market, not electricity. Energy generation remains the longer-term goal for the company, and the seed capital funds only the first physical plant. The $6.2 million will pay for the reactor build at the Massachusetts facility, including an ultrafast laser, optical components and neutron diagnostics, along with team expansion.

The round drew a mix of venture and mission-linked capital. Azolla Ventures led, with participation from Overlay, the Mass Clean Energy Center, the Neta Foundation, the Rothrock family, and P3A.

For buyers of rare isotopes and operators of fusion research reactors, the question is whether a benchtop platform can scale from prototype pressures to commercially meaningful tritium output. The company has separated its claim into two parts: a demonstrated compression result of 350 gigapascals, and an announced reactor that does not yet exist. The milestone that decides what happens next is the completion of that first compact reactor in Massachusetts, which will show whether weekly test cycles translate into isotope production at scale.