Stone to Silicon

Energy · February 2026

First private D-T fusion

A privately built machine fuses deuterium and tritium at 150 million degrees.

Helion's Polaris became the first privately built fusion machine to show measurable deuterium-tritium fusion, reaching 150 million °C. Helion is building its Orion plant to supply Microsoft.

See it in the living treeWikipediaSource

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 2

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Related measurements

The dashed line marks when it first worked.

Record fusion triple product Latest: 1.73×10²² keV·s/m³ (2017) Source: Wurzel & Hsu 2022, Physics of Plasmas 29, 062103; Wurzel & Hsu 2025 update, Physics of Plasmas 32, 112106

Nuclear electricity generation Latest: 2.81k TWh (2025) Source: Our World in Data