Helion Fusion Startup Hits 150 Million Degrees Celsius Milestone

Breakthrough paves way for 2028 commercialization goal, setting Helion apart from competitors

Apr. 11, 2026 at 5:27pm

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A highly structured abstract painting in soft, earthy tones of green, blue, and brown, featuring sweeping geometric arcs, concentric circles, and precise spirals, conceptually representing the complex scientific forces and concepts behind Helion's fusion reactor breakthrough.Helion's innovative fusion reactor design and record-breaking temperatures push the boundaries of clean energy technology.Everett Today

The fusion energy startup Helion, based in Everett, Washington, has achieved a significant breakthrough in its pursuit of fusion power. The company's Polaris prototype reactor has reached an astonishing 150 million degrees Celsius, which is three-quarters of the way towards the temperature required to operate a commercial fusion power plant. This achievement is a testament to Helion's innovative approach and its commitment to pushing the boundaries of fusion technology.

Why it matters

Helion's fusion reactor design and choice of deuterium-tritium fuel set it apart from competitors in the race to commercialize fusion power. The company's ability to reach record-breaking temperatures positions it as a strong contender to deliver on its contract with Microsoft to provide electricity starting in 2028, potentially revolutionizing clean energy generation.

The details

Helion's unique hourglass-shaped reactor chamber and use of powerful magnets allow for the injection of fuel and the creation of plasmas, which are then accelerated towards each other. This field-reversed configuration requires plasmas that are twice as hot as those in other reactors, and Helion's choice of deuterium-helium-3 fuel produces more charged particles, making it ideal for generating electricity directly.

  • Helion's Polaris prototype reactor reached 150 million degrees Celsius in April 2026.
  • Helion has a contract with Microsoft to deliver electricity starting in 2028.

The players

Helion

A fusion energy startup based in Everett, Washington, that is developing innovative reactor designs and utilizing deuterium-tritium fuel to push the boundaries of fusion technology.

David Kirtley

The co-founder and CEO of Helion, who expressed excitement about the company's breakthrough in achieving record-breaking temperatures in its Polaris prototype reactor.

Microsoft

A major technology company that has a contract with Helion to receive electricity from the company's larger commercial reactor, called Orion, starting in 2028.

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What they’re saying

“We're obviously really excited to be able to get to this place.”

— David Kirtley, Co-founder and CEO, Helion

“We were able to see the fusion power output increase dramatically as expected in the form of heat.”

— David Kirtley, Co-founder and CEO, Helion

What’s next

Helion's ultimate goal is to reach 200 million degrees Celsius, which the company's CEO considers the 'optimal sweet spot' for power plant operation. The company is also working on refining the fuel cycle, producing helium-3 with high efficiency, and plans to use deuterium-helium-3 fusion as the main source of power.

The takeaway

Helion's innovative approach and its ability to achieve record-breaking temperatures in its fusion reactor make it a strong contender in the race to commercialize fusion power. The company's unique reactor design and fuel choice, along with its contract with Microsoft, position it as a potential game-changer in the clean energy sector.