TAE Technologies, the California-based fusion company backed by Microsoft co-founder Paul Allen, said its latest and greatest plasma generator has exceeded the headline-grabbing performance of its previous machine.

“This announcement is an important milestone on our quest to deliver world-changing, clean fusion energy to help combat climate change and improve the quality of life for people globally,” Michl Binderbauer, the company’s president and chief technology officer, said in a news release. “This achievement further validates the robustness of TAE’s underlying science and unique pathway.”

The $100 million machine, which went into operation less than a year ago, has been christened “Norman” in honor of physicist Norman Rostoker, the late founder of TAE (formerly known as Tri Alpha Energy). It takes the place of TAE’s C-2U plasma generator, which maintained high-temperature plasma rings in confinement for a record-setting 5 milliseconds back in 2015. Over the course of more than 100,000 experiments, the maximum confinement time eventually went even longer, to 11.5 milliseconds.

TAE said that the C-2U experiment checked off half of what’s called the “Hot Enough, Long Enough” requirement — that is, demonstrating that a high-temperature plasma could be held in confinement long enough to sustain a nuclear fusion reaction. Such a reaction could take advantage of the same process that powers the sun to produce abundant, relatively cheap, relatively clean energy.

Just as the C-2U machine met the “Long Enough” standard, the Norman machine is making progress on the “Hot Enough” standard. After 4,000 experiments, TAE said the temperature of Norman’s plasma has reached a high of nearly 20 million degrees Celsius (35.5 million degrees Fahrenheit).

That’s almost twice as hot as C-2U’s top temperature, and hotter than the temperature of the sun’s core (which is estimated at 15 million degrees C, 27 million degrees F).

TAE attributed its rapid progress to its collaboration with Google on machine-learning simulations of plasma physics. The company is also taking advantage of a U.S. Department of Energy supercomputer program to boost its data-processing resources.

There’s still has a long way to go. TAE’s research team is aiming for a hydrogen-boron fusion reaction, which is cleaner than the typical deuterium-tritium reaction but more difficult to achieve. That means the target plasma temperature will eventually have to reach on the order of 3 billion degrees C, which will require building a successor to Norman and conducting years of follow-on experiments.

Despite the challenges ahead, TAE Technologies CEO Steven Specker said he was heartened by the latest achievement.

“It is profound to see TAE’s scientific innovations bear out in Norman’s performance,” Specker said in the news release. “Our remarkable

progress signals the reality of a future powered by fusion energy, and hydrogen-boron is as safe and clean a fuel source as you can find. It’s a win-win for us all.”

TAE’s approach to fusion involves shooting “smoke rings” of high-energy plasma at each other within a magnetic confinement chamber, with neutral beams directed into the chamber to improve plasma stability. In a recent interview, TAE’s Binderbauer told GeekWire that the technologies under development could be used for applications other than power generation.

“There’s a medical application that’s particularly interesting that we’ve started,” he said, “and we’ve enabled that because we’ve gotten these beams to reactor-level performance already.”

TAE says it has attracted $500 million in investment for private-sector fusion research over the past 20 years. In addition to Allen’s Vulcan Capital, institutional investors include the Rockefeller family’s Venrock venture capital firm and Rusnano, a Russian investment firm.

Other privately funded fusion ventures include Helion Energy in Redmond, Wash., which has won backing from tech billionaire Peter Thiel’s Mithril investment firm; and General Fusion, which is headquartered in Burnaby, B.C., and counts Amazon’s billionaire founder, Jeff Bezos, among its investors.

Those all come in addition to research efforts backed by government and academic funding, such as the multinational $20 billion ITER experimental reactor under construction in France, and the $1.1 billion Wendelstein 7-X stellarator in Germany.

For what it’s worth, the Joint European Torus, or JET, has achieved plasma temperatures of around 100 million degrees C (180 million degrees F). And for just an instant at a time, Europe’s Large Hadron Collider can create quark-gluon plasma at temperatures in excess of 5 trillion degrees C (9 trillion degrees F).