Fusion startup Helion hits blistering temps as it races toward 2028 deadline

Helion, a fusion energy startup based in Everett, Washington, has achieved a significant milestone by heating plasmas inside its Polaris prototype reactor to 150 million degrees Celsius—about 75% of the temperature it believes necessary for commercial fusion power. The company is the first fusion firm to operate using deuterium-tritium fuel, which has led to a dramatic increase in fusion power output in the form of heat. Helion’s reactor design, known as a field-reversed configuration, differs from the more common tokamak approach by compressing plasma in an hourglass-shaped chamber and generating electricity directly from the fusion reaction’s magnetic fields, rather than extracting heat. Helion aims to reach 200 million degrees Celsius to optimize power plant operation and plans to transition to deuterium-helium-3 fuel, which produces more charged particles conducive to its direct electricity generation method. Unlike many fusion startups targeting the early 2030s for grid electricity, Helion has a contract with Microsoft to supply