Squeezed by a metal wall moving in milliseconds, a fusion machine in Vancouver hit 12 million degrees Celsius this week, and no slow compression device had ever reached that mark before
The plasma inside the chamber lasted only milliseconds.
A metal wall closed around it, squeezing it tighter and tighter.
It moved the way a fist closes around a handful of clay.
It is detailed in a technical paper co authored with the UK’s national fusion authority, posted publicly and submitted for peer review at the same time.
Then the instruments at the edge of the machine recorded something.
A temperature the Sun’s own core never reaches.
So how did a wall moving this slowly get there first?
Why squeezing slowly turns out to matter
Almost every serious attempt to heat plasma to fusion temperatures has done so at extreme speed, in nanoseconds or microseconds, using record breaking lasers or sudden bursts of electromagnetic force. Slow compression works more like a hydraulic press, deliberate and controlled.
The tradeoff had always been assumed. Slower compression was thought incapable of reaching fusion temperatures, so most programs chased speed instead of patience.
The demonstration machine, known as LM26, became the first fusion device in the world to achieve 1 kiloelectron volt with slow compression. It heated magnetically confined plasma over milliseconds rather than the microseconds or nanoseconds used elsewhere, sitting in what the team calls a sweet spot of parameters believed necessary for commercial plants.
What the machine actually looks like
In LM26, compression comes from a solid metal wall rather than lasers or other methods pushed to physical extremes. The result looks less like a science experiment and more like heavy manufacturing equipment, with thick cylindrical walls, hydraulic actuators, and a plasma chamber no bigger than a large kitchen appliance.
The approach aims for fusion that is practical and economical, using a liquid metal wall that allows ordinary industrial materials. Rival approaches often demand exotic superconducting coils or components built to survive conditions found nowhere else in industry.
Liquid metal walls can simply be replaced.
That is what makes the design appealing to engineers planning a machine meant to run for decades, not days. The results were co published with the UK’s national fusion laboratory and measured using Thomson scattering methods, a technique precise enough that independent labs accept its readings without qualification.
The measurement and who verified it
The 1.1 keV electron heating result, equivalent to 12.6 million degrees Celsius, was measured just before peak compression. It is detailed in a technical paper co authored with the UK’s national fusion authority, posted publicly and submitted for peer review at the same time.
Submitting simultaneously to the public and to peer review is a deliberate choice, signaling a team confident enough in the data to let engineers worldwide read it before any journal weighs in.
Electron temperature was measured with both Thomson scattering and extreme ultraviolet diagnostics, and it came with meaningful ion heating. Ion heating is the harder physics, since fusion reactions happen between ions rather than electrons, so its presence adds weight to the claim. Only a few fusion companies have surpassed the 1 keV milestone, and all did so using other methods.
What the approach still has to prove
Twelve million degrees is genuinely hot, but it is not fusion hot. Deuterium and tritium, the hydrogen isotopes most fusion programs plan to burn, ignite near 100 million degrees Celsius, roughly eight times higher than what LM26 logged this month.
The machine’s designers know that.
They set 1 keV precisely because it is a recognized waypoint, not the destination. Upgrades to LM26 are underway now, aimed at higher compression ratios ahead of a 10 keV target, after which the program advances toward the Lawson criterion, the combination of temperature, density and confinement time required for net fusion energy.
The program aims to de risk the path to practical fusion power, with a goal of operating a first of its kind plant around 2035. A decade is a long runway, and the gap between 12 million and 100 million degrees is not trivial.
Why the method, not just the number, is the real story
The distinction between slow and fast compression may sound like a footnote, but it is closer to the whole argument. Laser driven approaches require optics costing millions of dollars each, degrading with every shot, while magnet based systems demand materials cooled near absolute zero.
This program’s bet is that a metal wall moving slowly can do what those systems do, at a fraction of the cost, built from parts a conventional manufacturer can supply. That logic connects to work happening elsewhere in unconventional energy storage.
Just as a printed staircase turns ordinary structural material into a battery, this machine bets that common metals, pushed with precision, can unlock physics once reserved for exotic hardware. And just as a passive sodium ion battery beat lithium iron phosphate on a 15 state grid by leaving out active cooling, the appeal here is what the design leaves out rather than what it adds.
The company’s chief executive put it plainly in the program’s technical documentation, noting that no one had reached 1 keV with practical slow compression before this month. Whether the next eightfold temperature jump follows the team’s timeline or takes longer, the record set on October 8 is measured, co signed by a national laboratory, and written down.
Hugo is an engineer with strong technical expertise. Multilingual from an early age, his writing combines technical clarity with a strong interest in science and energy.
