Helion has raised an additional $425 million to develop a fusion reactor that will provide electricity to Microsoft. This increased the startup's market valuation to $5.245 billion, TechCrunch reports.
Last month, the startup launched its seventh Polaris prototype, which could become the first fusion reactor to generate electricity. The prototype is located in a 2,508 m² building in Everett, Washington, and its construction took more than three years, which is considered fast by industry standards.
The startup has an ambitious agreement with Microsoft to create a fusion reactor that will provide data centers with electricity by 2028. In order to meet this deadline, the startup will need to develop its prototypes even faster in order to present the finished product in time.
Among the challenges Helion faces is the high demand for semiconductors for reactors. Polaris consists of 50,000 of these large-scale pulsed power semiconductors
The new investments will be used to set up its own production facilities, in particular for the production of capacitors, which usually have to wait up to three years when ordered from suppliers. Although the startup will have to set up supplies from scratch, Helion CEO David Kirtley is optimistic that the company will be able to complete the project on time.
Part of Helion's appeal - and part of its risk, according to critics - is that its approach to fusion energy is different from that of virtually every other startup in the sector.
In general, there are two main approaches: magnetic confinement uses powerful magnets to compress the plasma so that it becomes hot and dense enough to trigger fusion reactions that must burn continuously to produce steam to turn the turbine. Inertial containment directs powerful lasers at the fuel pellets, compressing them to the point where the fuel atoms fuse. In order to generate enough heat to power the steam turbine, the reactor must be triggered several times per second.
Helion's approach is radically different from the others. The startup uses a reverse-field reactor, and its device is shaped like an hourglass with a bulge in the middle. This device is wrapped in powerful magnets that guide and compress the plasma during each reaction, called a "pulse."
After the "pulse," the startup injects a mixture of deuterium and helium-3 into both ends of the device and heats it to form a plasma. Magnets then shape each plasma into a doughnut shape and guide them toward each other at speeds of more than 1 million miles per hour. When the plasmas meet in the center of the device, where the fusion chamber is located, they collide and are further compressed by another set of magnets. This process heats the plasma to a temperature of more than 100 million degrees Celsius, which causes a cascade of atomic fusion.